pilot scale studies on membrane based industrial wastewater reuse

PILOT SCALE STUDIES ON MEMBRANE BASED INDUSTRIAL
WASTEWATER REUSE APPLICATION IN HO CHI MINH CITY,
VIETNAM
by
Tra Van Tung
A thesis submitted in partial fulfillment of the requirements for the
Degree of Master of Science in
Environmental Engineering and Management
Examination Committee:
Nationality:
Previous Degree:
Scholarship Donor:
Prof. Chettiyappan. Visvanathan (Chairperson)
Prof. Ajit P. Annachhatre
Prof. Nguyen Thi Kim Oanh
Dr. Nguyen Phuoc Dan
Vietnamese
Bachelor of Biology
Dalat University
Dalat, Vietnam
International Fellowship Program
Ford Foundation, USA – AIT Fellowship
Asian Institute of Technology
School of Environment, Resources and Development
Thailand
May 2011
i
Acknowledgements
I would like to express my sincere thanks and deep gratitude to Prof. Dr. C.Visvanathan,
Chairman of the Examination Committee, who guided and helped whenever I was needed
throughout this research. His helpful suggestions and encouragements were the best things
that help my thesis success. He spent time checking though the draft, as well as gave clear
explanations.
I extend sincere thanks to Prof. Dr. Ajit P.A, Prof. Nguyen Thi Kim Oanh and Assoc. Prof.
Dr. Nguyen Phuoc Dan, Examination Committee members for their constructive
suggestions and valuable comments for the successful completion of this study.
Special thanks are given to Dr. Bui Xuan Thanh and Mr. Amila for their ideas and
guidance during my thesis research. I would like to express my sincere thanks to Mr.
Nguyen Van and other colleagues in the central wastewater treatment plant (CWWTP) of
Le Minh Xuan Industrial Park and also lab-employees of HCMC University of Technology
Lab who made favorable conditions for my works throughout my study in HCMC.
I deeply acknowledge to Norit Asia Pacific Pte. Ltd, Singapore for providing membrane
module for this research and valuable suggestions. I also would like to thank Mr.Aik Leng
who is a membrane expert of Norit Company for providing technical information during
pilot unit design, construction and operational stage.
Special thanks go to Vietnam administrative authorities in providing information for data
collection. I also enthusiastically acknowledge to all farmers for their participation in
providing information for questionnaire survey in my field work.
I am intensely indebted to the International Fellowship Programs (IFP) of Ford Foundation
Scholarship for providing financial support that made my dream come true in Master’
program at AIT-Thailand.
Last but not least, special appreciation is my family due to very cheerfully provided the
unending moral support and encouragement during my study in Asian Institute of
Technology - Thailand for two years.
ii
Abstract
Water pollution, salt intrusion and over exploitation of water resources are main causes of
water shortage in HCMC. Untreated industrial wastewater is a main cause of polluted
water resources that leads to many negative effects on agricultural activities in peri-urban
areas of HCMC. This result is lack of quantity and quality of water used for agriculture and
low crop yield. It also has adverse effects on farmer health such as itches and scabies, etc.
The amount of industrial wastewater discharged in 2010 is 241,000 m3/d which is expected
to increase to 376,000 m3/d in 2020. Thus, there is high potential for reuse of this treated
effluent for agricultural activities in HCMC.
Pilot scale study of airlift-membrane bioreactor (A-MBR) and UF membrane use as
tertiary treatment after conventional activated sludge process (CAS) was carried out at
central wastewater treatment plant (CWWTP) of Le Minh Xuan industrial park for 6
months. This study focuses on the treated water quality of A-MBR and UF process to
compare with effluent quality of CAS and standard for industrial wastewater discharge and
reuse to estimate potential applying membrane technology in treated industrial wastewater
reuse for agricultural activities in peri-urban areas of HCMC. Effluent COD of A-MBR,
UF and CAS process was 54, 68 and 87 mg/L, respectively. Effluent BOD5 of A-MBR, UF
and CAS process was 13, 15 and 18 mg/L, respectively. Effluent SS of A-MBR and UF
was not detected whereas effluent SS of CAS process was 50 mg/L. Effluent Ni and Cd
was not detected with three process. However, Effluent Zn of A-MBR, UF and CAS
process was 0.25, 0.27 and 0.28 mg/L, respectively. Effluent Cr of A-MBR, UF and CAS
process was 0.15, 0.60 and 0.96 mg/L, respectively. Effluent total coliform of A-MBR, UF
and CAS process was 1.3x102, 2.2x101 and 1.7x104 MPN/100 mL, respectively. Effluent
E.coli of A-MBR, UF was nearly not detected whereas effluent E.coli of CAS process was
1.4x103 MPN/100 mL. Effluent quality of A-MBR, UF is higher than CAS process.
Treated water quality of A-MBR and UF process meet standard for industrial wastewater
reuse for agriculture.
iii
Table of Contents
Chapter Title
Page
Title Page
Acknowledgement
Abstract
Table of Contents
List of Tables
List of Figures
List of abbreviations
i
ii
iii
iv
vii
viii
x
1 Introduction ........................................................................................................... 1 1.1 Background of the study .................................................................. 1 1.2 Problem statement ............................................................................ 1 1.3 Objective of the study ...................................................................... 2 1.4 Scope and limitation of the study..................................................... 3 2 Literature Review .................................................................................................. 4 2.1 Wastewater reuse ............................................................................. 4 2.1.1 Status of wastewater reuse ............................................................... 5 2.1.2 Impact of untreated wastewater reuse on human health and quality
of crops. ............................................................................................ 6 2.1.3 Wastewater reclamation ................................................................... 7 2.1.4 Different sources of wastewater ....................................................... 7 2.1.5 Roles of wastewater reuse ................................................................ 7 2.1.6 Quality of reused wastewater ........................................................... 8 2.1.7 Selection of wastewater treatment method ...................................... 9 2.1.8 Economic and social consideration ................................................ 10 2.1.9 Public acceptance ........................................................................... 10 2.2
Industrial wastewater and reclamation of industrial wastewater ... 11 2.2.1 Industrial wastewater ..................................................................... 11 2.2.2 Contaminations of industrial wastewater and its impact ............... 11 2.2.3 Reclamation of industrial wastewater ............................................ 11 2.2.4 Potential of industrial wastewater reuse......................................... 11 2.3
Conventional technologies for industrial wastewater treatment .... 12 2.3.1 A typically conventional technology for industrial wastewater
treatment......................................................................................... 12 2.3.2 Activated sludge process ................................................................ 13 2.3.3 Advantages and disadvantages of conventional technologies ....... 13 2.4
Membrane technologies for industrial wastewater treatment ........ 14 2.4.1 Background on membrane filtration .............................................. 14 2.4.2 Membrane operational parameters ................................................. 15 2.4.3 Transmembrane Pressure (TMP) ................................................... 16 2.4.4 Advantages and disadvantages of membrane filtration ................. 16 2.4.5 Potential membrane technology for water reuse ............................ 16 2.5
Membrane Bioreactor for industrial wastewater treatment............ 20 2.5.1 Membrane Bioreactor (MBR) ........................................................ 20 2.5.2 Applications of MBR for industrial wastewater treatment ............ 23 2.5.3 Advantages and disadvantages....................................................... 23 iv
2.5.4
2.5.5
2.6
2.7
2.7.1
2.7.2
Concepts of critical and sustainable flux ....................................... 24 MBR operation modes ................................................................... 24 Membrane fouling .......................................................................... 24 Membrane cleaning ........................................................................ 24 Physical cleaning............................................................................ 24 Chemical cleaning .......................................................................... 24 3 Methodology ....................................................................................................... 26 3.1 Selection of the study area ............................................................. 26 3.2
Data collection ............................................................................... 28 3.2.1 Background information ................................................................ 28 3.2.2 Questionnaire survey...................................................................... 28 3.3
Experimental setup and operation of pilot scale units. .................. 28 3.3.1 Le Minh Xuan industrial park and its characteristics of wastewater.
........................................................................................................ 30 3.3.2 Conventional Activated Sludge (CAS) .......................................... 31 3.3.3 Membrane module ......................................................................... 32 3.3.4 Airlift-Membrane bioreactor (A-MBR) ......................................... 33 3.3.5 A-MBR process flow ..................................................................... 34 3.3.6 Membrane bioreactor (A-MBR) operational sequence .................. 36 3.3.7 Ultrafiltration tertiary treatment ..................................................... 37 3.3.8 Backwash process of A-MBR and UF membrane ......................... 38 3.3.9 Chemical enhanced backwash (CEB) ............................................ 39 3.4
Sampling Methods ......................................................................... 40 3.5
Analytical parameters .................................................................... 40 4 Results and Discussion........................................................................................ 43 4.1
Status of water resources in HCMC ............................................... 43 4.2
Industrial water consumption in HCMC ........................................ 47 4.2.1 Industrial status in HCMC ............................................................. 47 4.2.2 Water demand for industrial .......................................................... 48 4.3
Water consumption for agriculture in peri-urban of HCMC ......... 48 4.3.1 State of agriculture in HCMC ........................................................ 48 4.3.2 Estimate water demand for agriculture .......................................... 50 4.4.1 Impact on surface water ................................................................. 51 4.4.2 Impact on ground water ................................................................. 52 4.4.3 Farmers’ perspectives .................................................................... 53 4.4.4 Impact on human health ................................................................. 57 4.5
Characteristic of Feed wastewater to A-MBR and UF .................. 57 4.6
Operating condition of A-MBR and CAS process......................... 59 4.6.1 Seed sludge acclimatization ........................................................... 59 4.6.2 Organic loading rate and F/M ratio ................................................ 59 4.6.3 pH, DO, Temperature and MLSS in the aeration tank................... 60 4.7
Effect quality of membrane systems and comparison with
conventional activated sludge and standard ................................... 61 4.7.1 Treated water quality ..................................................................... 61 4.7.2 Quality and reuse option ................................................................ 70 4.8
TMP of membrane systems............................................................ 72 4.9
Effect quality vs reuse standard ..................................................... 73 4.10
Operating problems and suggestion ............................................... 74
v
4.11
5
Cost of membrane .......................................................................... 74 Conclusions and Recommendations ................................................................... 77 5.1 Conclusions ................................................................................... 77 5.2 Recommendations for further studies ........................................... 78 References ....................................................................................................... 80
Appendice A ..................................................................................................... 86
Appendice B ..................................................................................................... 88
Appendice C ..................................................................................................... 89
Appendice D ..................................................................................................... 90
Appendice E ..................................................................................................... 95
Appendice F .................................................................................................... 103
Appendice G ................................................................................................... 113
Appendice H ............................................................................................... 11114
Appendice I..................................................................................................... 115
Appendice J .................................................................................................... 118
Appendice K ............................................................................................... 11121
Appendice L ................................................................................................... 125
Appendice M .................................................................................................. 134
vi
List of Tables
Table
2.1
2.2
2.3
2.4
2.5
2.6
2.7
2.8
2.9
3.1
3.2
3.3
3.4
3.5
3.6
3.7
4.1
4.2
4.3
4.4
4.5
4.6
4.7
4.8
4.9
4.10
Title
Page
Advantages and disadvantages of wastewater reuse ............................................. 5 Summary guideline for wastewater reuse for agriculture FAO guideline and
Eastern Mediterranean Region to compare with QCVN 24/2009/BTNMT for
industrial discharge into water body at level B. .................................................... 8 Potential of wastewater reuse of industries ......................................................... 12 Advantages and disadvantages of conventional water treatment........................ 14 Comparison between membrane processes......................................................... 15 Advantages and disadvantages of membrane filtration ...................................... 16 Summary of treated wastewater by membrane technology for wastewater reuse
18 Comparison of Submerged and Side Stream MBRs ........................................... 21 Cleaning Chemicals ............................................................................................ 25 Characteristics of wastewater in Le Minh Xuan industrial zone. ....................... 31 Characteristics of membrane used in A-MBR and UF experiment .................... 32 The operation conditions of membrane of A-MBR and UF experiments........... 33 Operational parameters of A-MBR ..................................................................... 34 A-MBR operational sequence ............................................................................. 36 Parameters and three sampling location.............................................................. 40 Analysistical parameters and method of analysis ............................................... 42 The necessary reduction of freshwater use to meet the desirable WSI in HCMC
in 2025................................................................................................................. 46 Salinity of Hoc Mon – Binh Chanh irrigation systems ....................................... 47 Agricultural area in HCMC in 2009 .................................................................. 48 Water demand for agriculture in HCMC ............................................................ 50 Pb concentration in vegetable grown in HCMC ................................................. 56 Characteristics of feed wastewater ...................................................................... 58 Operating conditions of CAS and A-MBR ......................................................... 59 Comparison the effluent of CAS, A-MBR and UF processes with the standards
71 Removal efficiency A-MBR at different three OLR .......................................... 74 Operational problems solution/suggestion of A-MBR and UF pilot scale system .
............................................................................................................................. 74 vii
List of Figures
Figure
Title
2.1
2.2
2.3
2.4
2.5
2.6
2.7
2.8
Integrated water cycle systems approach for water reuse ................................... 4 Outline secondary effluent reuse ......................................................................... 9 Benefits of wastewater reuse versus treatment cost .......................................... 10 Conventional wastewater treatment................................................................... 13 Diagram of a simple activated sludge system ................................................... 13 Basic phase of membrane process ..................................................................... 14 Two modes of membrane filtration ................................................................... 15 (1) internal membrane with suction pump; (2) External air lift membrane with
suction pump ..................................................................................................... 20 Framework of Study Plan .................................................................................. 26 Map of Ho Chi Minh City ................................................................................. 27 Experiment set up and opration at pilot scale units ........................................... 29 Treatability and operation.................................................................................. 30 Operating condition of bioreactor...................................................................... 34 Membrane module used in A-MBR and UF systems ........................................ 33 Operating process of A-MBR ............................................................................ 35 Photo of A-MBR system ................................................................................... 36 Process of UF membrane after CAS.................................................................. 38 Photo of UF system ........................................................................................... 38 Locations of Sampling ....................................................................................... 40 Sai Gon and Dong Nai river system .................................................................. 44 Existing and predicted water intake capacity of water resources in HCMC ..... 44 Comparison between water intake capacity and water demand in HCMC ....... 45 WSI of Sai Gon and Dong Nai rivers ................................................................ 46 Map of agricultural area and irrigation systems in HCMC ............................... 49 Schematic diagram of route of potential water resources pollution risk from
activities of IPs .................................................................................................. 51 Map of potential pollution streams in HCMC and study area ........................... 52 The impact of wastewater on agricultural activities based on farmers’
perception .......................................................................................................... 54 (a): Rice yield in Le Minh Xuan (b) Rice Yield in Tan Tao ............................. 55 Variation of feed COD and color during operating period................................ 58 Variation of feed conductivity during operating period .................................... 59 MLSS variation of OLR1, OLR2 and OLR3 during operating period................ 61 Variation of pH value of CAS, A-MBR and UF processes during operating
period ................................................................................................................. 62 Variaton of effluent COD of CAS, A-MBR and UF processes during operating
period ................................................................................................................. 63 Average effluent COD of CAS, A-MBR and UF processes ............................. 63 Average effluent BOD5 of CAS, A-MBR and UF processes ............................ 64 Variation effluent SS of CAS, A-MBR and UF processes during operating
period ................................................................................................................. 65 Average effluent SS of CAS, A-MBR and UF processes ................................. 65 Variation of effluent conductivity of CAS, A-MBR and UF processes during
operating period ................................................................................................ 66 3.1
3.2
3.3
3.4
3.6
3.5
3.7
3.8
3.9
3.10
3.11
4.1
4.2
4.3
4.4
4.5
4.6
4.7
4.8
4.9
4.10
4.11
4.12
4.13
4.14
4.15
4.16
4.17
4.18
4.19
Page
viii
4.20
4.21
4.22
4.23
4.24
4.25
Average effluent conductivity of CAS, A-MBR and UF processes and feed
water .................................................................................................................. 67 Variation of color effluent of CAS, A-MBR and UF processes during operating
period ................................................................................................................. 67 Average feed water color and effluent color of CAS, A-MBR and UF processes
........................................................................................................................... 68 Variation of UV254 permeate A-MBR and UF processes .................................. 69 (a) Variation TMP of A-MBR at Flux 30 L/m2.h (b) Variation TMP of A-MBR
at Flux 45 L/m2.h ............................................................................................... 72 Variation TMP of UF membrane during the operating period .......................... 73 ix
List of Abbreviations
AAS
A-MBR
ASP
BOD
BTNMT
Atomic Absorption Spectrophotometer
Airlift- Membrane Bioreactor
Activated Sludge Process
Biochemical Oxygen Demand
Bo Tai Nguyen & Moi Truong (Ministry of Natural Resource and
Environment)
BW
Backwash
CAS
Conventional Activated Sludge
CEB
Chemical Enhanced Backwash
CFU
Colony Forming Unit
COD
Chemical Oxygen Demand
CWWTP
Central Wastewater Treatment Plant
DO
Dissolved Oxygen
DONRE
Department of Natural resource and Environment
DONRE
Department of Natural resource and Environment
DPA HCMC Department of Planning and Architecture of HCMC
DWRPIS
Division for Water Resources Planning and Investigation for the South
EPC
Environment Protection Center
F/M
Food/ Microorganisms
FAO
Food and Agricultural Organization
HCMC
Ho Chi Minh City
HDARD
Department of Agriculture and Rural Development, HCMC
HEPA
Ho Chi Minh City Environmental Protection Agency
HEPZA
Ho Chi Minh City Export Processing and Industrial Zone Authority
HRT
Hydraulic Retention Time
IER
Institute of Environmental Resources
LMX IP
Le Minh Xuan Industrial park
MBR
Membrane Bioreactor
MF
Microfiltration
MLSS
Mixed Liquor Suspended Solid
MPM
Most Probable Number
N
Nitrogen
NF
Nanofiltration
NTU
Nephelometric Turbidity Units
OLR
Organic Loading rate
P
Phosphorous
QCVN
Quy Chuan Viet Nam (Vietnamese Regulation)
RO
Reverse Osmosis
SRT
Sludge Retention Time
SS
Suspended Solids
SV
Solenoid Valve
TCVN
Tieu Chuan Vietnam (Vietnamese Standard)
TMP
Transmembrane Pressure
TSS
Total Suspended Solids
UF
Ultrafiltration
UNDP
Units Nation Development Program
USEPA
United States Environmental Protection Agency
UV
Ultraviolet
x
VIWASE
WHO
WMG
WSI
WTP
Vietnam Water Supply and Environment Company
Word Heath Organization
Water morning glory
Water stress index
Water Treatment Plant
xi
Chapter 1
Introduction
1.1
Background of the study
Recent years in Vietnam, industrial untreated wastewater which contents hazardous
materials having negative effects on human health and other living things is directly
dumped into water bodies leading to water pollution. Million cubic meter of untreated
wastewater per day is discharged into rivers, lakes or ponds where they are the water
supply for agriculture, irrigation, and navigation which become increasingly heavy
polluted. Polluted water resources are the causes of disease of residents, especially poor
people and farmers. Water pollution also has negative effects on the qualities of
agricultural products, vegetable growths, as well as public health due to direct use of
water pollution for agriculture.
Contaminants of industrial wastewater before return to water bodies must be minimized
by many different wastewater treatment technologies to prevent the potential negative
impact on public health as well as plants and animals. Membrane technology is a one of
novel technology in wastewater reclamation and reuse due to successful in removing most
of contaminants from wastewater that leads to increasing the potential for even greater
reuse. Moreover, membrane technology takes many advantages such as low energy cost,
low capital investment, chemicals requirements, and small space requirement compared to
other systems.
Membrane bioreactor (MBR) is advanced technology, compared to conventional activated
sludge. It can increase the efficiency of removing contaminants due to preventing leakage
of undecomposed substances by biological decomposed process. As a result, qualities of
treated water can be improved that can lead to meet the standard for wastewater reuse.
Moreover, MBR can bring many other advantages such as totally rejected suspended
solids by membrane, high sludge retention time leading to good condition for slowly
growing microorganisms such as nitrifying bacteria in system resulting high nitrogen
removal in wastewater, reducing reactor volume due to maintaining higher biomass in
bioreactor, and less sludge production. In addition, pathogens are rejected by membrane
module positively affecting disinfection process.
Effluents of wastewater after membrane treatment can reject the amount of chemicals that
can be discharged into water bodies. Therefore, treated industrial wastewater reuse has
huge potential to reach the increasing water demands due to increasing population, and
increasing consumption of human activities.
1.2
Problem statement
Ho Chi Minh City (HCMC) is the largest industrial City in Vietnam. Water consumption
is increasing continuously due to growth population, economic development, especially
water usage for industrial. However, water resources are increasingly polluted by
untreated wastewater or not well treated wastewater directly discharged into water bodies
and agricultural land from industrial parks in HCMC. Among the existing industrial parks
in HCM City, only six industrial parks had the central wastewater treatment plant (HEPA,
2007). The total wastewater volume generated daily from industrial parks was about
32,600 m3 and only 15,100 m3 (46%) has been treated. Untreated wastewater reuse for
1
agriculture has many negative effects on public health, the qualities of crop products, and
vegetable growth.
Untreated wastewater is a main cause of water resources pollution in South of Vietnam.
As a result, many large rivers in South of Vietnam such as Sai Gon river, Dong Nai River,
Thi Vai River which are major water supply for human activities are highly polluted.
COD and BOD in these rivers are higher than Vietnamese permitted standard, and heavy
metals are detected. The canals in HCMC will receive daily discharge of 2,100,000 m3
from domestic and industrial wastewater in 2020. The BOD5 load was 170 tons per day
in 2000 and projected load will be 380 tons/d in 2020. It perceptibly recognizes that all
canals in the HCMC have been heavily polluted. The bad smell frequently emits and
worse at low tides (HEPA, 2006).
The effluents of conventional wastewater treatment plant in Vietnam may be not meet
Vietnamese standard for wastewater discharge or reuse. According to Anh, (2009)
industrial wastewater treatment in Vietnam, in 2006, 134 out of 247 establishments
(54.3%) had treatment systems, only 34 met environmental standard (13.8%). In 2007,
263 out of 513 establishments (51.3%) had treatment systems, only 67 met environmental
standard (13.1%). In 2008, 601 out of 804 establishments (74.7%) have treatment
systems, only 287 met environmental standard (35.7%). In HCMC, many industries still
have not been complied with the regulation such as incompletion of construction of in-situ
wastewater treatment plant (WWTP) or poor operation and maintenance of in-situ WWTP
that resulted in poor effluent, not met the industrial effluent quality standards (HEPA,
2008). There is also not enough space for expending wastewater treatment plants of
industrial parks in some old industrial parks in Vietnam.
Moreover, water resources is increasingly scarce due to many reason such as climate
change, salination of water resources, decreasing ground water levels, increasing
consumption of water, as well as receiving untreated wastewater discharge.
This study indentified the potential of industrial wastewater reuse in HCMC. Airlift
membrane bioreactor (A-MBR) and UF membrane system used as tertiary treatment were
applied to treat industrial wastewater. Efficiencies of pollutants removal by A-MBR and
UF membrane were compared to conventional activated sludge (CAS).
Well treated industrial wastewater can bring to many benefits such as preventable
degradation of water resources, improvable efficiencies of water consumption, and
preventable negative effects of wastewater on public health and the qualities of
vegetables. It is also developing new water resource in order to overcome with water
shortage, and toward sustainable development.
1.3
Objective of the study
This study was conducted to achieve following objectives
1. To estimate the wastewater reuse potential for agriculture in Ho Chi Minh City
(HCMC);
2. To investigate the treated effluent qualities of ultrafiltration (UF) tertiary treatment
process and membrane bioreactor (A-MBR) process;
3. To compare the treated effluents from UF tertiary treatment and MBR with
existing conventional activated sludge (CAS) process;
4. To identify the optimum operating conditions for MBR and UF membrane system.
2
1.4
Scope and limitation of the study
This study investigated the potential of wastewater reuse for agriculture, and pilot scale
study with membrane units in order to accomplish the objectives mentioned above with
following steps and boundary limits.
•
Secondary data collection on amounts of industrial wastewater discharges and
estimate demand of water supply for agriculture in HCMC.
•
Secondary data collection on the untreated wastewater reuses in the HCMC and its
health impact. Farmers who live in peri-urban in HCMC and other stakeholders
were interviewed and information on wastewater reuse aspects was gathered.
•
Secondary and primary data were analysed and wastewater reuse potential in the
HCMC will be estimated.
• A pilot scale A-MBR and a UF tertiary treatment unit were operated throughout
the study period in Le Minh Xuan industrial zone. Treated water quality of the two
pilot scale units and existing CAS unit in the wastewater treatment plant were
monitored during 7 months.
• Treated water quality were analyzed and compared with the existing Vietnamese
industrial wastewater discharge standards (QCVN 24/2009/BTNMT) and
international wastewater reuse standards, USEPA Guideline for Water Reuse and
(FAO, 1985) Guidelines for interpretation of water quality for irrigation.
3
Chapter 2
Literature Review
2.1
Wastewater reuse
Sustainable water management leads to increasing seeking to alternative water resources
such as water reuse or minimise wastewater. Water reuse must be concerned in the period
water crisis. Water reuse is described as treated wastewater to a standard where as it can
be used. Minimise water use and maximum water reuse within the built environment is
important goal in sustainable development. Figure 2.1 shows the diagram of integrated
water cycle systems approach for water reuse (Landcom, 2006). This can be achieved by
using water resources for most appropriate purposes, identifying and maximizing
alternative water resources and minimizing the impact of wastewater on receiving aquatic
systems.
Figure 2.1 Integrated water cycle systems approach for water reuse
4
According to the U.S. Environmental Protection Agency (EPA) defines wastewater reuse
as, “using wastewater or reclaimed water from one application for another application.
The deliberate use of reclaimed water or wastewater must be in compliance with
applicable rules for a beneficial purpose such as landscape irrigation, agricultural
irrigation, aesthetic uses, ground water recharge, industrial uses, and fire protection”.
With different treatment measure, wastewater can reuse for different purpose that depends
on requirement level. The value of wastewater reuse depends on the quality of water
supply to compare with water demand of users, available water reserves, the water supply
capacity of recent water resources and the cost of water reclamation. The factors should
be considered treatment level, the scale of project and water distribution network to assess
the potential wastewater reuse. Wastewater reuse will be more favourable, if there is
available water distribution network or recycled wastewater to sever for a lager number of
users.
Wastewater reuse brings to many advantages and disadvantages in table 2.1 (McKenzie,
2005).
Table 2.1 Advantages and disadvantages of wastewater reuse
Advantages
• Reducing the demands on freshwater
resources.
• Reducing the need of large
wastewater treatment plant.
• Reducing the volume of wastewater
discharge.
• Wastewater with rich nutrients can
increase agricultural production.
• Reducing pollution of rivers or
ground water
Disadvantages
• Reuse of wastewater may be seasonal in
nature, resulting in the overloading of
treatment and disposal facilities during the
rainy season; if the wet season is of long
duration and/or high intensity, the seasonal
discharge of raw wastewaters may occur.
• Health problems, such as water-borne
diseases and skin irritations, may occur in
people coming into direct contact with
reused wastewater.
• In some cases, reuse of wastewater is not
economically feasible because of the
requirement for an additional distribution
system.
• Application of untreated wastewater as
irrigation water or as injected recharge water
may result in groundwater contamination.
Source: McKenzie, 2005
2.1.1 Status of wastewater reuse
In dates back to 5000 years, wastewater has been used for agriculture and irrigation.
Wastewater reused by farmers has been recorded in 16th and 18th centuries in Germany
and Unites Kingdom respectively. In China and India, wastewater reuse also has a long
history. In 19th century, untreated wastewater discharged into water bodies has been
indirectly used as unintentional potable water supplies.
5
Nowadays, wastewater reuse is common in the world. In Mediterranean countries,
wastewater as a water source has been used due to increasing water demand from
agriculture or irrigation and chronic water shortage (Angelakis et al, 1999). In European,
reclaimed wastewater is predominantly reused for agriculture, and urban or environmental
application due to the face of increasing water demand, increasing water supply costs, and
increasing competition for good quality fresh water reserves (Bixio et al, 2006).
According to Qadir et al, (2010), farmers who live in urban and peri-urban in developing
countries are often using wastewater for irrigation due to having no choice. Wastewater
provides nutrients or cheaper than other water resources.
In Vietnam, wastewater reuse for agriculture and irrigation has been used for centuries by
farmers due to a cheap, reliable water source, and supplying nutrients. Domestic and
industrial wastewater, nowadays, is widely used, especially in suburban areas (Anh,
2001). Nowadays, water reuse plays a significant role due to population growth,
increasing water resource pollution.
Comprehensive assessment of wastewater reuse in HCMC is difficult due to new thing
and not yet any investment of projects on that issue. On the other hand, wastewater reuse
was not yet address in the overall planning of the city or in the strategy of environmental
protection or environmental plans for water supply in the future. To estimate potential of
wastewater reuse in HCMC bases on the estimation of fresh water revers, degradation of
natural water resources and analysis of steady quantity and quality of wastewater
reclamation as well as the cost of wastewater reuse to compare with the cost of water
exploitation from natural water resources.
Moreover, water stress index (WSI) is also used to estimate the potential of wastewater
reuse in HCMC. When WSI is less than 10%, the pressure of water use on water resources
is low. WSI value in range 10 – 20%, water resources become limited and it is higher
20% that it needs large efforts on integrated management in order to balance supply and
needs, and the government should have specific action programs to solve conflict among
competitive consumers (Angelakis, 2003).
2.1.2 Impact of untreated wastewater reuse on human health and quality of crops.
Wastewater without proper management is used for agriculture that can lead to serious
risks to public health and the environment. Chemical pollutants and microbial pathogens
in wastewater are the main causes of these risks (Fatta-Kassinos et al, 2010). Inorganic
matters are a particular concern for reuse applications. Water with highly saline irrigation
can severely degrade soils over time, and heavy metals may accumulate in soils, and later
they may accumulate into the food chain, and finally into human body that may be a cause
of cancer.
Chemical pollutants in wastewater reuse for agriculture can directly damage of the plants.
The results of experiments have been demonstrated that corn took up lasalocid and
monensin, and sorghum, pea and corn were influenced their growth by uptake of
sulfadimethoxin. The chemical accumulation of plants depends on the part of plants. For
example, accumulation of chemicals in roots of corn and sorghum more than the shoots.
Moreover, they also have indirect effects on growth of plants because chemicals can
affect soil bacteria. As a result, decomposition of organic matters in soil is slower. Thus
recycle nutrient process is more slowly that has impact on suppling nutrients for plants
(Migliore et al., 1997).
6
Biological pathogens have the potential risks to public health due to exposure to
microbiological contaminants in water. There are four main groups of biological
pathogens divided into bacteria, viruses, protozoa and helminths contained in wastewater
(Tutuka et al, 2009).
2.1.3 Wastewater reclamation
When understanding of the relationship between water supply and diseases became clear,
there were many engineering solutions which were implemented to develop the
alternative water sources such as using reservoirs and aqueduct systems, relocation of
water intakes, and water and wastewater treatment systems. There were the controlling
practiced wastewater irrigations in sewage farms of many countries in Europe, America
and Australia (Vigneswaran et al, 2004).
There are many available technologies for reclamation wastewater. It depends on the
degree of treated requirement varies according to the specific reuse application and
associated water quality requirements. They are divided into three major groups including
the simplest treatments, more complex treatment systems, and more advanced
technologies. Sedimentation, aerobic biological treatment, oxidation ponds, biological
nutrient removal, and disinfection are known as the simplest treatments. Activated carbon,
air striping, ion exchange, chemical coagulation and precipitation are more complex
systems. Membrane technology such as microfiltration, nanofiltration, ultrafiltration and
reverse osmosis are used as advanced technologies. They are very attractive application
for wastewater reclamation due to success in removing most contaminants from
wastewater that leads to increasing the potential for even greater reuse (Visvanathan and
Asano, 2001). It also consists of moving-bed sand filter, granular activated carbon
adsorption bed and ozone disinfection (Petala et al, 2006).
2.1.4 Different sources of wastewater
Municipal wastewater was more concern on reuse due to vast amount of wastewater daily
discharge. However, industrial wastewater is worth to study for reuse for irrigation
because it considers that around 20% of it around the worldwide water production.
Food processing industries, containing high organic substances have high potential reuse
for agriculture to compare with other industries. Organic substances have positive effects
for some crop yields and no accumulation harmful substances in the soil.
2.1.5 Roles of wastewater reuse
Reclamation of wastewater to reuse may play an important role in the developmental
strategies for the utilization of water resources. There are various applications of
reclaimed wastewaters. It is most commonly for agriculture and irrigation. In urban areas,
reclaimed water is reused for street washing, fire systems or vehicle washing. It is also
reused in industrial plants such as cooling water, and reuse for enrichment of groundwater
bodies. Thus, wastewater reuse may strengthen water savings generating supplementary
water sources, which are especially important in areas with limited rainfalls (AbdelJawad, 1999).
Costs relating to water supply or wastewater disposal may are the causes of attractive
option to wastewater reuse. Wastewater reuse has positive influents on wastewater
treatment costs and water supply. It reduces the costs of head works and distribution
7
systems, and also motivates behind many reuse schemes. The total costs of water supply
or wastewater disposal have three major components such as the cost of fresh water,
wastewater disposal, and regeneration treatment. These costs can be minimized by
determining the optimum post-treatment or regeneration contaminant concentration (Feng
et al, 2004).
Wastewater reclamation and reuse also play the significant roles of the hydrologic cycle
in urban, agricultural, and industrial areas. The hydrological cycle is the processes of
continuous transport of water in the environment. Transport of water consists of some
main water cycle in nature such as fresh and saline surface water resources, atmospheric
water vapour, surface groundwater, and associated with various land use functions
(Visvanathan, Chongrak and Thammarat). The benefit of wastewater treatment can
improve the water quality of the effluent. Thus it can reduce the risk of illness when the
water supply is used by the public (Olivieria et al, 2005).
2.1.6 Quality of reused wastewater
Required quality of wastewater reuse depends on different using objective. It is highly
concerned about health protection.
Guidelines for wastewater reuse in agriculture are different among different countries
because it was built basing on economic, environmental, social differences of each
country. Table 2.2 shows guideline of wastewater reuse for agriculture of FAO and
Eastern Mediterranean Regions to compare with QCVN 24/2009 for industrial wastewater
discharge into water body at level B.
Table 2.2 Summary guideline for wastewater reuse for agriculture FAO guideline
and Eastern Mediterranean Region to compare with QCVN
24/2009/BTNMT for industrial discharge into water body at level B.
Parameter
pH
COD
BOD5
TSS
Total colif
E.coli
Cd
Zn
Ni
Cr
Unit
mg/L
mg/L
mg/L
MPN/100mL
MPN/100mL
mg/L
mg/L
mg/L
mg/L
FAO
Jordan
Kuwait
Oman
6-9
<20
<20
0.1
2.0
0.2
0.1
6-9
500
200
150
1,000
0.01
5.0
0.2
0.1
6.5-8.5
100
20
15
400
0.01
2.0
0.2
0.15
6-9
200
20
30
0.01
5.0
0.1
0.05
Saudi
Arabia
6-8.5
10
10
2.2
0.01
2.0
0.2
0.1
Tunisia
6.5-8.5
90
30
30
1,000
0.01
5.0
0.2
0.1
QCVN
24/2009
5.5-9
100
50
100
5,000
0.01
3.0
0.5
0.1
Source: CEHA, 2006
In general, Guideline of wastewater reuse for agriculture of Eastern Mediterranean Region
is more strictness than FAO guideline and QCVN 24/2009. However, QCVN 24/2009 is
stricter than FAO guideline. Therefore, QCVN 24/2009 can consider to apply for
wastewater reuse for agriculture in Vietnam. Ranges of these parameters such as pH,
COD, BOD5, TSS total coliform, Cd, Zn, Ni and Cr are around 5.5 -9, 90 – 500 mg/L, 10
8
-200 mg/L, 10-150 mg/L, 400-5000 MPN/100 mL, 0.01 – 0.1 mg/L, 2.0-5.0 mg/L, 0.1-0.5
mg/L, 0.05-0.15 mg/L, respectively.
2.1.7 Selection of wastewater treatment method
Most technologies used for treated wastewater reuse are fundamentally derived from
water and wastewater treated technology. However, since wastewater reclamation plays a
significant role in wastewater reuse and economic value, opportunities for adopting
technological innovation are much greater for applications in treated wastewater reuse.
Figure 2.2 shows reuse options and various treatment alternatives for wastewater reuse
(Atasoy.E et al). Different treated degrees require different treatment technologies which
are divided preliminary, primary, secondary, tertiary, and advanced treatment. The
simplest treated technologies are known as solid/liquid separation processes and
disinfection whereas more complex treated technologies are the combination of different
processes involved physical, chemical and biological processes to multiply barrier treated
approaches for contaminant removal.
Figure 2.2 Outline secondary effluent reuse
(http://nett21.gec.jp/GESAP/themes/themes2.html)
9
2.1.8 Economic and social consideration
Cost estimation for wastewater reuse including capital cost, operation and maintenance
costs, energy costs, revenue and timing of expenditure and receipt is essential to optimize
the net benefits from implementation. Beside that, social benefits of wastewater reuse
need to be assessed (Bahri, 1999; Haruvy Nava, 1997, 1998; Huravy.N, et al, 1999).
These estimations are useful because it has positive and negative effects. Positive effects
comprise value of water, nutrient, improvement of environment, public health, benefits
for water appropriated authorise, discharge reduction, elimination of certain treatment
process to meet mass limits and recycled water sale. It also has negative effects such as
risk due to pathogens and organic matters, accumulation of toxic elements on crops, costs
for storage and conveyance and treated cost (Kretschmer, N et al,).
Figure 2.3 shows the benefits of wastewater reuse versus treatment cost cited from
Shelef.G, 1991. This figure shows a conceptual economic justification. It is delineation of
benefits which are grained by setting public health and environmental damage. Benefits of
sum of reused wastewater value (line A-C) and preventing health and environmental
damage value (line A-B) is greater than treatment cost (line A-D). These benefits are
different in different countries.
Figure 2.3 Benefits of wastewater reuse versus treatment cost (Shelef.G, 1991)
2.1.9 Public acceptance
Public acceptance for wastewater reuse plays important role because it will be fail without
absence of social support. It needs the understanding of social and cultural aspects of
10
water reuse. The factors need to analyse to encourage public acceptance including costs,
benefits and health issues as well as legislation.
2.2 Industrial wastewater and reclamation of industrial wastewater
2.2.1 Industrial wastewater
Industrial wastewater is wastewater, generated in the process of industrial production
from the production stages and activities to serve for production. Industrial wastewater is
very diversity and difference on composition and waste quantity. It can be contaminated
due to inorganic and organic pollutants containing in it. If it is not appropriately treated, it
can make serious environmental pollution.
2.2.2 Contaminations of industrial wastewater and its impact
The characteristics of industrial wastewater are very various that depends on industrial
processing. In general, industrial wastewater contains heavy metals, harmful chemicals,
and other toxic substances, so industrial wastewater can be more serious than domestic
wastewater. Serious hazardous wastes having in industrial wastewater have worsened the
situation significantly. Industrial wastewaters have negative effects on the agricultural
economy and public health (Mohsen, 2004).
It also contains the pollutants including pharmaceuticals, antiseptics, UV filters,
surfactants and fragrances. Moreover, industrial wastewater may contain the hundreds of
different pathogens that can be the causes of disease by carrying humans and animals.
Untreated industrial wastewater disposal or inadequate treatment is also the main source
of pathogens in the water environment.
2.2.3 Reclamation of industrial wastewater
The reclamation of industrial wastewater has taken place in many developmental periods
which were started from direct discharge to recycling and reuse. The simple physiochemical treatment systems are adopted to treat industrial wastewater, but it is rapid
degradation of environment leading to forcing the governments to implement more
stringent legislations for industrial wastewater discharge. The strict standards of industrial
discharge have led to application of more advanced technologies for industrial wastewater
treatment (Mohsen, 2004).
2.2.4 Potential of industrial wastewater reuse
The different degrees of potential for industrial wastewater treatment and reuse are
different from different industries. Although in the same industry, the characteristics of
wastewater and volumes are different, if the processes are different. The different volumes
and concentrations in industrial wastewater are the most important factors to consider
applying reuse technology.
Industrial wastewater discharges into water bodies also leading to increasing costs for
industries located downstream. It is also a cause of over natural purification capacities and
dissolved oxygen is depleted below levels in water that can have negative impact on
aquatic life. A good solution for industrial wastewater reuse is, the wastewater discharge
should be met the requirement of effluent standard.
11
Industries have the high volume of wastewater, but pollutant concentrations in wastewater
is low that have high potential for reuse. However, industries having the low volume of
wastewater with high concentration of pollutants are more difficult to reuse. Based on
some of these governing factors, wastewater reuse potential is summarized in Table 2.3.
Table 2.3 Potential of wastewater reuse of industries
High Potential
Medium Potential
Low Potential
• Pulp and Paper
• Slaughterhouse
• Tanneries and leather finishing
• Cotton Textile
• Dairy
• Pesticide
• Pulp and Paper
• Canning and Food Processing
• Rubber
• Glass and Steel
• Distillery
• Aluminum
• Wool Textile
• Explosives manufacturing
• Photographic Processing
• Paint manufacturing
• Chemical
• Fertilizer
• Oil refining
• Petroleum
• Electroplating
• Meat Processing
Source: Visvanathan, and Takashi Asano (2001)
2.3 Conventional technologies for industrial wastewater treatment
2.3.1 A typically conventional technology for industrial wastewater treatment
Conventional wastewater treatment consists of a combination of physical, chemical, and
biological processes and operations to remove solids, organic matter and, sometimes,
nutrients from wastewater. It includes a pre-treatment, primary treatment, and secondary
treatment. Pre-treatment step consists of screens, and an aerated grit removal tank. It can
remove materials which can damage or clog the pumps and skimmers of primary
treatment clarifiers. Primary treatment is usually a sedimentation tank that is used after
pre-treatment step. Settleable organic and inorganic solids are removed by sedimentation
tank. Floating materials are removed by skimming. Secondary treatment usually consists
of two steps including bioreactor and sedimentation. The residual organics and solids
which are not treated by primary treatment can be removed by secondary treatment. The
objective of bioreactor is degradation of organic materials, and secondary sedimentation
removes settleable materials or floating. Bioreactor can work at two different operating
conditions such as aerobic and anaerobic condition. Figure 2.4 shows the basic process of
conventional wastewater treatment.
12
Figure 2.4 Conventional wastewater treatment
2.3.2 Activated sludge process
The concentration of organic pollutants in wastewater is removed by biological treatment
process with most widely using activated sludge. The activated sludge is a suspended
solid, and it is predominantly in aerobic condition. The activated sludge maintains a high
biomass by means of solid that is recycled from secondary clarifier. Figure 2.5 shows the
layout of a typical activated sludge system.
Figure 2.5 Diagram of a simple activated sludge system
Settleable biomass is separated from liquid by secondary sedimentation tank. The
production of gelatinous matrix allows the gathering of bacteria, protozoa, and other
microorganisms that is responsible for the removal of organic matter.
2.3.3 Advantages and disadvantages of conventional technologies
Removal efficiencies of conventional wastewater treatment plant is different that depend
on different parameters. For example, the removal efficiency of suspended solids (SS),
BOD5 and COD are 95%, 66% and 65%, respectively (Colmenarejo et al, 2006).
Conventional wastewater treatment is not successful removal with the trace chemical
contaminants which are persistence in wastewater. The trace chemical contaminants
include heavy metals, inorganic compounds, and organic pollutants such as endocrine
disputing compounds or pharmaceutically active compounds (Fatta-Kassinos et al, 2010).
Table 2.4 shows the advantages and disadvantages of conventional water treatment.
13
Table 2.4 Advantages and disadvantages of conventional water treatment.
Advantages
Disadvantages
• Simple and easy operation
• Low capital cost due to cheap building
materials
• Suitable for pure surface water
• Low maintenance and operation cost,
low cost of water supply, suitable for
weakly developing countries
Source: Fatta-Kassinos, 2010
• Waste chemical
• Low pathogens removal rate
• Low natural organic mater removal
rate
• Large area requirement
2.4 Membrane technologies for industrial wastewater treatment
2.4.1 Background on membrane filtration
Membrane filtration is physical separating process under driving force due to very small
pores of membrane. Pressure is required to drive the liquid passing though membrane
layer. The pressure required for separating process is varies which depend on the size of
pores, concentration, electrical charge or temperature. Figure 2.6 shows the basic phase of
a membrane process.
igure 2.6: Basic phase of membrane process
Figure 2.6 Basic phase of membrane process
There are four main kinds of membrane which are microfiltration, ultrafiltration,
nanofiltration, and reserse osmosis. These categories depend on the rejection particle size
of membrane. Table 2.5: shows comparison between membrane processes.
14
Table 2.5 Comparison between membrane processes.
Items
Pore size
(μm)
Pressure
range
(bar)
Separation
potential
Flux range
(L.m2/h.bar)
Microfiltration
(MF)
0.02 – 2.0
0.1 – 0.2
Suspensions,
Emulsions
>50
Ultrafiltration
(UF)
0.005 – 0.02
1.0 – 5.0
Macromolecula
solution, Emulsions
10 - 50
Nanofiltration
(NF)
0.001 – 0.02
5.0 – 20.0
Low to medium
molar mass solution
1.4 - 12
Reverse
Osmosis (RO)
0.0001 – 0.001
10 - 100
Aqueous low molar
mass solution
0.05 – 1.4
There are two operational modes of membrane filtration which is namely; dead end and
cross flow filtration. Figure 2.7: shows two modes of filtration.
Figure 2.7: Modes of filtration
Figure 2.7 Two modes of membrane filtration
In cross flow filtration, feed water is pumped parallel with the sure face of membrane.
The rejected materials can be recycled into the system back again. It is different when in
dead end filtration, feed water is pumped though the membrane and permeate pass though
the pores of membrane. The rejected materials are continuously accumulated on
membrane surface. In crossflow filtration requires higher energy than dead end, but less
fouling performance on membrane compared to dead end filtration with low energy
requirement, but high membrane fouling.
2.4.2 Membrane operational parameters
The most important parameters of membrane performance are transmembrane pressure,
membrane consistence, and permeate flux. They have the relationship that is given in
equations below.
Rt = Rm + Rc + Rf
15
Where:
J: permeate flux (L/m2.h)
UP: transmembrane pressure (kPa)
μ: Viscosity of the permeate (Pa.s)
Rt: Total resistance (1/m)
Rc: Cake resistance (1/m)
Rf: Fouling resistance caused by solute adsorption (1/m)
2.4.3 Transmembrane Pressure (TMP)
Difference of pressure between feed side and permeate side is defined as transmembrane
pressure. Low pressure membrane is affected by driving force which is associated with
any given flux. TMP is an overall indication of feed pressure requirement, used with the
flux to assess the fouling of membrane (WEF press, 2006).
2.4.4 Advantages and disadvantages of membrane filtration
Membrane application in water desalination or purification has advantages such as energy
efficiency, more simple to operate and higher quality of product. However, it still exits
disadvantages such as some time requirement for pre-treatment due to sensitivity to
concentration polarization and membrane fouling. The long time reliability of membrane
is not proven. It is not robust and can be destroyed. Table 2.6 shows advantage and
disadvantage of membrane filtration.
Table 2.6 Advantages and disadvantages of membrane filtration
Advantages
-
Disadvantages
Continuous separation
Low energy consumption
Can be easily combined with other
exiting technical
Up-scaling easy
Membrane properties are variable
and can be adjusted
-
Membrane fouling
Low membrane life time
Operating costs and maintains
2.4.5 Potential membrane technology for water reuse
The degree of treatment required varies according to the specific reuse application and
associated water quality requirements. The simplest treatments involve solid/liquid
separation such as sedimentation, aerobic biological treatment, oxidation ponds,
biological nutrient removal, and disinfection. More complex treatment systems involve
combinations of physical, chemical, and biological processes employing multiple barrier
treatment approaches for contaminant removal such as activated carbon, air striping, ion
exchange, chemical coagulation and precipitation. More advanced technologies include
microfiltration, nanofiltration, ultrafiltration and reverse osmosis. Membrane technology
is used to separate solids from wastewater in wastewater treatment. Membrane technology
can use as tertiary treatment in wastewater treatment plant. Use of membrane technology
has been successful in removing most contaminants from wastewater thereby increasing
the potential for even greater reuse (Visvanathan and Asano, 2001).
16
The membrane filtration system could remove all suspended solids, fecal coliforms, and
giardia cysts. It could also significantly reduce human enteric viruses such as reovirus and
enterovirus. The water reclamation plant at Eraring Power Station demonstrates the
potential for reuse of wastewater in power generation and other industrial manufacturing
facilities (Vigneswaran et al, 2004)
Membrane technology was used in wastewater treatment for reuse very normal. It met
almost standard of wastewater reuse, especially reuse for agriculture or irrigation. Table
2.7 shows the summary of some membrane technology applied in wastewater treatment
for reuse and permeate of membrane systems was compared to wastewater reuse for
agriculture of FAO, 1985. From these results showed that almost effluent of membrane
technology met standard for wastewater reuse in agriculture.
17
Table 2.7 Summary of treated wastewater by membrane technology for wastewater reuse
18
Table 2.7: Summary of treated wastewater by membrane technology for wastewater reuse
Membrane Wastewater
pH
COD
BOD5
EC
TSS
Total coliform
E.coli
Reference
technology
(mg/L) (mg/L) (µS/cm) (mg/L) (CFU/100mL.) (CFU/100mL)
Tam.L.S et al,
3.4
<2
569
<2
17.5
Municipal
6.9
MBR
2007
nd
<2
27
<2
<2
WW
5.4
MBR+RO
2
<2
659
<2
17.9
7.7
MF
nd
<2
33
<2
<2
5.5
MF+RO
MBR
Municipal
50
0.76
35
Arévalo.J et
UF
WW
75
1.2
0
al, 2009
UF+RO
Industrial WW 5.6
3.2
139
Chen.H.H et
al, 2005
Galil.N.I and
2.5
7.1
129
7.8
MBR
*Paper mill
Levinsky.L,
10.8
45
342
7.6
*Food
2007
production
9.0
2.1
385
*Petrochemical 8.0
WW
MBR
Industrial WW 7.2
2
nd
nd
nd
nd
You.S.J and
MBR+RO
6.8
2
nd
nd
nd
nd
Wu.D.C, 2009
MBR
Municipal
7.6
22
nd
2.07
0.10
Zanetti.F et al,
WW
2010
MBR
Industrial WW
10-30
<5
<2
<100
<20
Melin.T et al,
2006
MBR
Industrial WW
20
nd
<102
Wisneiwski.C,
2007
MBR
Petrochemical
7.6
38-78
3-5
<2.5
Qui.J.J et al,
WW
2007
DebiK.E et al,
8750
110
Industrial WW
UF
2010
3210
29
NF
4730
15
UF+NF
FAO, 1985
Reuse criteria for
6.6
<20
700-3000
<20
<200
agriculture
8.4
nd: not detected
19
Table 2.7: Summary of treated wastewater by membrane technology for wastewater reuse (Cont)
COD
BOD5
Membrane Wastewater pH
EC
TSS
Total coliform
E.coli
(mg/L) (mg/L) (µS/cm) (mg/L) (CFU/100mL.) (CFU/100mL)
technology
UF
Waste pond
7.8
94.5
1.8
1.98
4
1
RO
7.1
2.83
2.25
0.224
0
0
MBR
Municipal
=
=
<2
=
<2
<200
<20
WW
MBR
Paper mill
6-9
49.7
<5
1674
<2
WW
MBR
Municipal
<3
<1
<50
WW
UF
Municipal
43
2400
nd
146
11
WW
UF+RO
Steel WW
6.65
2.32
2,700
0.5
3,000
MBR
Industrial
7.6- 50-202
0 -14
WW
8.2
MBR
Municipal
6-7
21
4
2
MBR+ RO WW
6
43.3
MBR
Industrial
7.69 21.26
1.6
WW
MBR
Municipal
6.9
17.3
5.2
4
WW
MBR
Municipal
87
31
0
0
WW
MBR
Municipal
23-56
4-12
-63
WW
MBR
Municipal
24
4
<0.5
0
0
WW
Reuse criteria for
6.5
<20
700<20
<200
agriculture
8.4
3000
Viana, P. Z. et al,
2005
FAO, 1985
Alaboud.T, 2009
Saddoud.A et
al, 2007
Moeslang.H and
Brockmann.M,
Lopez.A et al,
2006
Lee.J.W et al,
2004
Wiszniowski.J et
al, 2010
Piyakuldumrong.P
and Araki.S, 2007
Colic.M and
Yunhua.Z, 2010
Liu.Z et al, 2006
Hotchkies.J.W,
2003
Zang.Y et al, 2007
Oron.G et al, 2006
Reference
2.5 Membrane Bioreactor for industrial wastewater treatment
2.5.1 Membrane Bioreactor (MBR)
Membrane bioreactor is the combination of two processes including biological treatment
process and membrane separating process. The biodegradation of organic mattes of
wastewater occurs in the bioreactor, and membrane system separates the treated water
from the mixed liquor.
The operations of membrane bioreactor process are wider different range of parameters
than the conventional activated sludge process. Solid retention time (SRT) of MBR can
exceed 30 days compared to 5 to 7 days of conventional activated sludge (CAS). The
food/Microorganisms (F/M) ratio of MBR is less than 0.1 per day, while F/M of CAS is
0.2 to 0.5 per day. Low F/M ratio occurs in MBR because of high mixed liquor suspended
solid (MLSS) in bioreactor which is range from 8.00 to 20,000 mg/L compared to 1,200
to 4,000 mg/L in CAS processes (Metcalf and Eddy, 2003; WEF, 2006).
There are two types of MBR which are membrane unit is located out side the bioreactor
(external loop), and located inside the bioreactor (internal loop), (Figure 2.8:1, 2 ).
External membrane module is generally developed due to its compactness. It is easy
maintenance because of the outside bioreactor. Submerged or immersed membrane
bioreactor (iMBR) is put directly inside the bioreactor. iMBRs generally requires less
energy-intensive, than external MBR. It also requires low transmembrane pressure due to
using air fluid as turbulence supply.
Figure 2.8 (1) internal membrane with suction pump; (2) External air lift membrane
with suction pump
Applications of both systems have advantages and disadvantages that is showed in the
table 2.8. The coarse bubble diffuser in the submerged configuration is generally used due
to provide a turbulent crossflow velocity over the surface of the membrane. It also
reduces the build up of material at the membrane surface, and thereby increases the
operational cycle of the system (Joseph and Visvanathan, 2005).
20
Table 2.8 Comparison of Submerged and Side Stream MBRs
Parameter
Submerged MBR
Aeration Cost
High (90%)
Pumping Cost
Low
Flux
Low
Foot Print
Large
Cleaning Requirements
Less Frequent
Operating Cost
Lower
Capital Cost
High
Source: Kurian Joseph and Visvanathan. C.
Side-Stream MBR
Low (20%)
High (60-80%)
High
Smaller
More frequent
Higher
Low
Food to Microorganisms (F/M) ratio
F/M is the rate of COD or BOD per unit volume of mixed liquor.
and
Where F/M: Food to biomass ratio, g BOD or bsCOD/g VSS.d.
Q: Influent wastewater flowrate, m3/d.
S0: Influent BOD or bsCOD concentration, g/m3.
V: Aeration tank volume, m3.
X: Mixed liquor biomass concentration in the aeration tank, g/m3.
HRT: Hydraulic retention time of aeration tank, V/Q.d.
A low F/M ratio implies a high MLSS and a low sludge yield
Mixed Liquor Suspended Solids (MLSS)
The concentration of suspended solids in mixed liquor is defined as MLSS. The unit of
MLSS is usually expressed in milligrams per liter (mg/L). It is also known as the amount
of biomass within the reactor. Mixed liquor is defined as the mixture of raw wastewater
and activated sludge which are contained in a bioreactor in the activated sludge process.
MLSS concentration can provide the reasonable indication of fouling propensity, but this
relationship is rather complex. Increasing MLSS can have negative, positive or
insignificant impact on membrane permeability. For example, high MLSS concentration
(30mg/L) has negative effects on membrane fouling. On the other hand, low MLSS
concentration at 6 mg/L reduces membrane fouling. However, it has insignificant effects
at 8-15 mg/L of MLSS concentration (Judd, 2006).
Dissolved oxygen (DO)
Aerobic microorganisms require oxygen for respiration. Dissolved oxygen concentration
in water depends on several different conditions such as temperature, solubility of gas,
pressure, and concentration of the impurities in the water.
21
DO concentration in water about 0.2 mg/L or above inhibits nitrate reduction due to
repressing the nitrate reduction enzyme. At DO concentration of 0.13 mg/L, the
denitrification ceases in a highly dispersed growth (Metcalf and Eddy, 2003; WEF, 2006).
DO have impact on membrane fouling of MBR though system biology. High dissolved
oxygen concentration in water can support better filterability. Oxygen limitation is a cause
of low cell surface hydrophobicity which has potential cause of membrane fouling (Judd,
2006).
Hydraulic Retention Time (HRT)
HRT has effect on membrane fouling. Increasing HRT leads to reducing membrane
fouling. Increasing organic loading rate and higher MLSS concentration result in reduce
of HRT (Harada et al, 1994).
Sludge Retention Time (SRT)
SRT is probably the most important operating parameter which impact on the membrane
fouling though MLSS concentration. It ultimately controls biomass characteristics. MBR
operates at higher SRT that can lead to increasing MLSS, but this in it self is not a cause
of excessive fouling. When SRT is reduce from 10 to 2 days, the membrane fouling rate
increases nearly 10 times. Corresponding to F/M ratio and MLSS are from 0.5 to 2.4 L/d
and 7.8 to 6.9 g/L, respectively (Trussell et al, 2006).
Effects of temperature on bioreactor operation
Temperature affects soluble oxygen in water. High temperature reduces dissolved oxygen
in water compared to low temperature. The optimum temperature for bacteria activities
ranges from 25 oC to 35 oC. When temperature rises to 50 oC, aerobic digestion and
nitrification are stoped (Metcalf and Eddy, 2003; WEF, 2006).
Temperature has effect on membrane filtration though permeate viscosity. Higher
temperature increases COD removal. At low temperature, foulant materials highly deposit
on membrane surface compared to high temperature.
J = J20*1.025(T-20)
Where J: Flux at the process temperature
J20: Flux at temperature of 20 oC
T: Temperature
Effects of pH
Nitrification is sensitive with pH. At pH of less than 6.8, rates of nitrification significantly
decline. If pH value about 5.8 to 6.0, the rates of nitrification may be 10 to 20 percent of
the rate at pH of 7.0. At the range of pH 7.5 to 8.0, optimal nitrification rates happen.
Nitrification rates is normally maintained at pH value of 7.0 to 7.2 (Metcalf and Eddy,
2003; WEF, 2006).
22
2.5.2 Applications of MBR for industrial wastewater treatment
The MBR technology is consequently an attractive option for the treatment of such
industrial wastewater. The removal efficiencies of MBR applied for seafood wastewater
treatment are high removal organic matters such as removal BOD5 (99%), COD and TOC
(85%) (Porntip et al, 2006). MBR is also feasible to treat the petrochemical wastewater,
and the product quality consistently meets the requirement for discharge (Qin et al, 2007).
Membrane bioreactor displays many advantages compared to conventional activated
sludge process. The effluent with high quality such as free from solid and germ meets
many current standards throughout the world, and also over come with increasingly
stringent standard of tomorrow (Wisniewski, 2007).
2.5.3 Advantages and disadvantages
CAS process is widely used in treating municipal or industrial wastewater. However, it
usually suffer failing in sedimentation process and thickening process because of the
growth of bacteria in the sludge suspension. MBR can apply to take numerous advantages
over CAS process. Among many biological processes, a membrane bioreactor (MBR) has
been recently most attracted because of acceptable level of effluent quality with simple
application or modification (Scholz et al, 2000, and Holler et al 2001). However, MBR
technology also has limited such as rapid decline of permeate flux due to membrane
fouling (Dijk and Roncken, 1997). The physicochemical characteristics and the
physiology of activated sludge have effects on membrane fouling (Chang and Lee, 1998).
The major advantages of the membrane bioreactors are:
Eliminated suspended solid by membrane separation or settleability of the sludge has no
effect on the quality of treated effluent.
Sludge retention time (SRT) can be maintained long time due to independent of hydraulic
retention time that results in complete growth of slow microorganisms such as nitrifying
bacteria. Reactor volume will be reduced because the microorganisms can disperse as
long as desired, and the overall activity level is possible to maintain at high concentration
in bioreactor. Moreover, Sedimentation tank or post-treatment is not requirement to
achieve for wastewater reuse.
It increases the treatment efficiency due to preventing the leakage of undecomposed
substances. Biodegradable substances have no endless accumulation within the treatment
process. Moreover, the low molecular weights can be broken down and gasified by
microorganisms, as a result, the quality of treated water raises.
Pathogens such as bacteria and viruses can be removed as expected leading to ecological
sound due to reducing force to the disinfection process.
Sludge product is reduced which is compared to conventional activated sludge processes,
due to maintaining low F/M (food/microorganisms) ratio. It can maintain a high sludge
capacity due to no effect of the fluctuations on volumetric. It is also no occurring of odour
dispersion.
23
However, according to Franca Zanetti et al, (2010), the disadvantages of MBR system are
high installation and management costs due to membrane fouling and subsequent
membrane cleaning.
2.5.4 Concepts of critical and sustainable flux
Critical flux is permeated flux after the occurrence of flux decline and before membrane
fouling. Two distinct forms of the critical are namely no fouling and little fouling which
occur at subcritical operation for strong and weak forms (Le-Clech et al, 2006).
The sustainable flux is defined as the flux for which transmembrane pressure gradually
increases at an acceptable rate, so chemical cleaning is not necessary (Ng et al, 2005).
Sustainable flux can be assessed for a longer filtration, while critical flux is mainly
determined in short term for filtration.
2.5.5 MBR operation modes
Two main operating modes of MBR are constant pressure and constant flux filtration. The
mode of constant pressure filtration is a rapid flux decline at the start of filtration and
gradually decreasing until reaching the steady state. The mode of constant flux filtration is
less fouling probability. According to Le-Clech et al, 2006, the large amount of particles
deposits on the membrane surface in the initial constant flux filtration. However, it may
bring benefits as a pre filter for membrane fouling due to reducing internal membrane
fouling.
2.6 Membrane fouling
When the particles get clog on the membrane surface or inside the membrane pores that
lead to membrane fouling. That is the causes of flux decline and affects the quality of
permeate product. Membrane fouling can require chemical cleaning or membrane
replacement. According to Baker, 2004, various types of foulants such as collidal,
microorganisms (bacteria, fungi), organic (olis, polyelectrolytes, humic substances) and
scaling mineral precipitates are the main causes of membrane fouling. There are three
main factors such as biomass characteristics, operating condition, and membrane
characteristics which have impact on membrane fouling (Chang et al, 2002).
2.7 Membrane cleaning
2.7.1 Physical cleaning
Physical cleaning of MBR is normally achieved either by backflushing, or relaxation to
remove gross solids which accumulate on membrane surface. It is simply stopping
permeation while air bubbles are continuing to scour the membrane. It has benefits when
these two techniques are used in combination, due to enhancement of backflushing by air
bubbles.
2.7.2 Chemical cleaning
Chemicals can use for membrane cleaning to remove recalcitrant foulants on membrane.
The membrane fouling may be the causes of irreversible process that the ordinary
cleaning method does not recover the loss of permeate flux due to plugging of solid
particles or large solutes on membrane (Lin and Espinoza-Gomez, 2005). Sodium
hypochlorite can be minimized the membrane biofouling. Low concentration of chemical
24
cleaning agent can be added to the backflush water to produce a “chemically enhanced
backflush” (CEB). The functions of chemical cleaning are showed in the table 2.9
Table 2.9 Cleaning Chemicals
Chemicals
NaOCl
Application
Destruction/removal of
organics
HCl
Removal scaling
NaOH
Various components
Citric acid
Removal of scaling
Source: Triqua, 2002.
Concentration
Max.Conc.allowed
500 ppm
1000 ppm
pH= 2
pH = 12
pH = 2
pH = 1
pH = 12
25
Chapter 3
Methodology
3.1
Selection of the study area
This study comprises of two segments to achieve the objectives as mentioned in Chapter
One. Segment one investigated the potential of wastewater reuse for agriculture in periurban area in Ho Chi Minh City (HCMC), Vietnam. Segment two was conducted in Le
Minh Xuan industrial zone, HCMC, Vietnam with a pilot scale airlift membrane
bioreactor (A-MBR), a pilot scale ultra filtration (UF) treatment unit and an actual scale
conventional activated sludge (CAS) process. Among the three treatment units A-MBR
and CAS was worked as secondary treatment units of industrial wastewater treatment
plant, while the UF was used as the tertiary treatment unit for further polishing of CAS
effluent. Figure 3.1 illustrates the framework of the study.
Figure 3.1 Framework of Study Plan
26
This study was carried out in the peri-urban area of Ho Chi Minh City (HCMC), Vietnam,
and Le Minh Xuan industrial zone which is located in Binh Chanh District is chosen to do
experiments of the membrane application for industrial wastewater treatment. HCMC is
located in the South in Vietnam and at 10010’-10038’ North and 106022’-106054’ East,
with a total agricultural area 121,313 ha (ARDS, 2009). Until 2008, there are 14 industrial
parks in HCMC (HEPZA, 2008). Where 80,500 ha is covered by agricultural lands among
that; 27,131, 10,000, 2,000, 1,792 and 11,000 ha is covered by area of rice, vegetable ,
maize, sugar cane, rubber tree and fruits tree, respectively (ARDS, 2009). Agricultural
production is mainly carried out in peri-urban area such as Hoc Mon District, Cu Chi
District, Binh Chanh District, and District 12 in HCMC. Figure 3.2 shows HCMC map
and Binh Chanh District map where the study was carried out.
Figure 3.2 Map of Ho Chi Minh City
27
3.2 Data collection
To achieve the objectives 1 and 2 that were mentioned in section 1.3, secondary data
collection through available literature and primary data collection through a questionnaire
survey was carried out. The study was conducted in the peri-urban region indicated in the
Figure 3.1.
3.2.1 Background information
Available secondary data on wastewater discharge and agricultural reuse was collected
from literature. Missing data was collected through discussions and questionnaire survey.
Information was focused on the causes of water resources pollution, the status of
wastewater reuse, number of industrial wastewater streams that discharge into water
bodies, and wastewater reuse impact on crops and health. Moreover, status of treated or
untreated wastewater from industrial zones in HCMC was analysed to estimate industrial
wastewater quality, discharged into water bodies, and the data of surface water quality are
collected to estimate the status of water quality, supplying for agriculture.
3.2.2 Questionnaire survey
The purposes of questionnaire survey are to attain information about wastewater reuse for
agriculture. Questionnaires are distributed to farmers who mainly live in peri-urban in
HCMC. They were asked the questions related to available water resources such as water
using for agriculture, status of wastewater reuse, causes of water pollution, impact of
wastewater reuse for agriculture on the yields of agricultural crops and famers health,
demand of water for agriculture, and water quality issue. The information collection from
survey was analysed to find out the results. (Questionnaire is presented in the Appendix
D).
3.3 Experimental setup and operation of pilot scale units.
Membrane bioreactor and UF membrane system were set up in connection with the
exiting industrial wastewater treatment plant in Le Minh Xuan industrial zone. Figure 3.3
shows experimental set up and operation at pilot scale units. Indicators of CAS effluent
and membrane permeate were compared to Vietnamese standard for industrial wastewater
discharge (QCVN 24/2009/BTNMT) which is given in appendix A, United States
Environmental Agency (UNEPA) is given in appendix B, and FAO guideline in appendix
C.
The existing CAS and pilot scale units at A-MBR and UF was operated and treatability
was assessed as shown in figure 3.4.
In addition, the performance of MBR was determined by measuring permeate flux, flux
qualities, and flux decline at different operating conditions such as pressures. Moreover,
MBR optimization was done with respect to F/M ratio, temperature, DO and MLSS.
28
Figure 3.3 Experiment set up and opration at pilot scale units
29
Figure 3.4 Treatability and operation
3.3.1 Le Minh Xuan industrial park and its characteristics of wastewater.
Le Minh Xuan IP (LMX IP)
Le Minh Xuan industrial park (IP) is located in area of Tan Nhut and Le Minh Xuan ward,
Binh Chanh District in HCMC, Vietnam. Total area of all the industrial zone is 100 ha.
Construction of houses and factories are 66.23 ha. Land for building management and
central service area is 5.53 ha. Green space is 11.14 ha. Land for construction of roads is
15.8 ha and land hub infrastructure is 1.2ha (Figure E1 and E2, Appendix E).
Production activities in LMX IP is very diversity such as production of battery, pesticide,
rubber and plastic, mechanisms, textile and dying, tanning, plating, food production,
parking and environmental treatment (Thanh, 2009).
Water consumption
Water volume supplying for factories and enterprises accounts for 77.4% of total water
consumption in LMX IP. Amount of water demand for different production is different.
Figure E.3 shows the percentage of water consumption for different production in LMX
IP (Thanh, 2009) (See in Figure E3, Appendix E).
Collection system and wastewater treatment
LMX IP has a separately collection system for rainwater and wastewater. Rainwater is
collected in the general storm water drainage system of the industrial park and directly
discharged into irrigation canals around the area. Domestic wastewater and product
wastewater collected from factories and enterprises after local pre-treatment sent to
central wastewater treatment plant. Treated wastewater was discharged into the canal 8.
Industrial wastewater is compared to QCVN 24/2009 at level B for industrial wastewater
30
discharge. Table 3.1 shows the influent and effluent of wastewater characteristics of Le
Minh Xuan Industrial Park.
Table 3.1 Characteristics of wastewater in Le Minh Xuan industrial zone.
Parameters
Unit
pH
Color
Pt-Co
COD
mg/L
BOD5
mg/L
TSS
mg/L
Total N
mg/L
Total P
mg/L
Total Fe
mg/L
As
mg/L
Hg
mg/L
Cr3+
mg/L
Zn
mg/L
Coliform
MPN/100 ml
Source: Thanh. (2009); Chi. (2008)
Raw
Wastewater
7±1.5
800±600
3,159±600
475±106
2137±1637
102±59
9.7±0.4
270
0.072
Undetected
12.18
57.28
15x104
Treated
Wastewater
7
180
69
6
13
6.1
0.56
0.38
0.028
Undetected
Undetected
3.039
Undetected
QCVN 24/2009
(level B)
5.5-9.0
70
100
50
100
30
6
5
0.1
0.01
1
3
5.0 x 103
Central wastewater treatment plant (CWWTP)
Area of the central wastewater treatment plant (CWWTP) of LMX IP is 1 ha and located
in inside the IP. It was covered by four roads namely as 8, 10, 11 and 12 road. CWWTP
has two parallel systems operated with total capacity of 4,000 m3/d and has been running
for 10 years. Whole information of LMX IP was presented in Appendix E. A mount of
wastewater daily discharge was unsteady. During Tet’s holiday wastewater did not
discharge due to stoped production of factories. A mount of wastewater collected from
factories around 6,000 m3/d was over the capacity of central wastewater treatment plant
(CWWTP) that is why a new system is building with capacity 2,000 m3/d (Figure E4,
Appendix E). As a result, the secondary sedimentation tank did not work well that let to
sludge floating in surface of tank and increasing SS concentration effluent in some days.
Collected rain water system and wastewater system is separated in LMX IP. Rain water is
collected and discharge into canal 8. Wastewater from factories and domestic is collected
into opening tank before pump to wastewater treatment system. Opening collected tank is
main cause of rain water can diluted wastewater in rain season.
3.3.2 Conventional Activated Sludge (CAS)
Schematic diagram of CWWTP of LMX IP was presented on Figure E7 in Appendix E.
Collected wastewater from factories and enterprises passes though the screen to remove
coarse materials and stored in equalization tank. Air is supplied and NaOH or HCL is
used to adjust pH at neutral. PAC and polymer are used for coagulation and flocculation
for SS removal at primary sedimentation tank. Wastewater passed though primary
sedimentation tank is collected at neutralization tank and adjusted pH to neutral by NaOH
or H2SO4.
31
Wastewater is distributed into aerobic tank. Air is supplied by air compressor. Operating
condition of aerobic tank is suitable for microorganisms and biodegradation of organic
materials. DO in aerobic tank is maintained from 2.5 to 4.5 mg/L. Mixed liquid suspended
solid (MLSS) is from 4,500 to 6,500 mg/L. pH from 7 to 8. Sludge retention time is 22.5
day and hydraulic retention time is 19.6 hours. Organic loading rate (OLR) is 0.75 kg
COD/m3.d and temperature range from 28 to 38 oC. Sludge product is sent to fertilizer
Company for composting. Schematic diagram of CWWTP was presented on Figure E.7
(Appendix E)
BOD5/COD ratio is used to evaluate the biodegradability of wastewaters. With low
unbiodegradable particulate COD fraction, the ratio is 1.8 to 1.9. For raw wastewater with
high unbiodegradable particulate COD fraction, the ratio is 2.0 to 2.1 (Hoover., et al.
1953; Ekama and Marais, 1978). Feed COD is 3,159 mg/L and feed BOD5 was 550 mg/L.
The ratio COD/BOD5 of LMX IP is 5.7. It is very high the ratio for unbiodegradable
particulate COD fraction. It means that raw wastewater of LMX IP is difficult for
biodegradation.
V = 1,800 m3; Sludge daily withdraw of CAS process: Qw= 80 m3/day
Calculate SRT = V/Qw = 1,800/80 = 22.5 days
3.3.3 Membrane module
Membrane X-flow module (airlift-membrane (A-MBR) and Aqualex-membrane (UF))
made by Norit Company is used in this study. Table 3.2 shows the specification of
membrane X-flow modules.
Table 3.2 Characteristics of membrane used in A-MBR and UF experiment
Description
Membrane material
Membrane type
Name
Module configuration (mm)
Membrane length (m)
Diameter (inch)
Effective surface area (m2)
Nominal pore size (MWCO) (µm)
Maximum flux (L/m2.d)
Recommended flux (L/m2.d)
Configuration
Operating pressure range (bar)
Maximum operating temperature (oC)
A-MBR membrane
UF membrane
PVDF
UF (cross flow)
Tubular
Airlift
5.2
1
4
1.6
0.05
75
35
Inside – Out
<2
45
Polysulfone
UF (dead end)
Hollow fiber
Aquaflex
0.8
1
4
6.2
0.03
120
50
Inside - Out
<6
45
Operating conditions of membranes is designed base on characteristics of membrane and
the instructions of Norit experts. They also based on the exiting conclusion of Le Minh
Xuan industrial park. Table 3.3 shows operating condition of membrane of A-MBR and
UF in experiments.
32
Table 3.3 The operation conditions of membrane of A-MBR and UF experiments
Item
A-MBR
UF
50
30
15
18
15
8.3
10
60
30
25 (only backwash time)
Feed flow (L/min)
Filtration time (min)
Backwash (s)
Backwash flow (L/min)
Air supply (L/min)
Figure 3.5 shows actual membrane module which will be used for A-MBR and UF
systems in this study.
Aqualex-membrane
(UF)
Airlift-membrane
(A-MBR)
Figure 3.5 Membrane module used in A-MBR and UF systems
3.3.4 Airlift-Membrane bioreactor (A-MBR)
A-MBR module was comprised three main parts as a bioreactor tank, an airlift-membrane
and a permeating collected tank. A-MBR was operated in external crossflow mode.
Bioreactor
Figure 3.6 indicated the operating condition of bioreactor.
33
Figure 3.6 Operating condition of bioreactor.
Sludge retention time (SRT) was 40 days. Sludge volume getting out bioreactor tank from
the bottom was 5.5 and 4.75 L/day related to 0.22 m3 and 0.19 m3, respectively.
Mixed liquor suspended solid (MLSS) is maintained operating condition in bioreactor
about 7,000 - 8.500 mg/L. Air was supplied oxygen for microorganisms demand by a
compressor. A-MBR was designed with parameters hereafter. Table 3.4 shows the
operational parameters of A-MBR.
Table 3.4 Operational parameters of A-MBR
Characteristics
Operation range
Membrane surface area
Flow rate
Influent COD
Loading rate
HRT
SRT
Volume of MBR
Feed pump
Circulating pump
Suction pump
Backwash pump
Air flow rate for Bioreactor
Air flow rate for Membrane
Unit
L/m2.h
m2
L/h
mg COD/L
kg COD/m3.d
hour
day
m3
m3/h
m3/h
L/h
L/h
L/h
L/h
Value
30 and 45
1.6
48 and 72
350, 450 and 724
0.18, 4.1 and 5.7
4.6, 2.6 and 3.1
40
0.19 and 0.22
3.6
1.5
72
4,800
1,800
900
3.3.5 A-MBR process flow
The process flow of the A-MBR is given in Figure 3.7. Effluent from primary
sedimentation tank was pumped to the bioreactor across a sedimentation tank (500 L) and
34
a screen (1 mm opening) to remove coarse materials that can negatively affect on
membrane. Bioreactor volume is controlled by a level controller which can control steady
wastewater volume in bioreactor by a controlling float. Figure 3.8 shows photo of AMBR system.
Wastewater treated by biological process is pumped into the ultrafiltration membrane
module by a feed pump, and permeate is passed though membrane by supporting of a
suction pump. In filtration period, solenoid valve 1 (SV1) was opened while SV2 was
close. Manual valve V1 and V5 were opened while manual vale V2, V3 and V4 were
closed. Concentrate was returned to bioreactor. Permeate was stored in a tank with the
volume about 100 liters. The small percentage of permeate was used to clean membrane
by regular backwash process or chemical cleaning process.
To check the flow rate and pressure, a flow rate gauge and pressure gauge are installed on
the pipe before membrane. Three pressure gauges were installed in membrane module to
determine the loss of pressure pass though the membrane or they can use for testing transmembrane pressure (TMP). This is important value to monitor.
A compressor was installed to supply air for bioreactor to supply oxygen for oxidation of
organic compounds by microorganisms, and for membrane module cleaning to control
fouling. Air flow rate supply for bioreactor and membrane was 1,800 L/h, and 900 L/h,
respectively.
Air was pumped to membrane though feed side during operation of A-MBR to enhance
membrane fouling control.
Membrane was operated 20 minutes, and then backwash was done in 15 second. The
experimental setup was operated automatically by automatic control program. Membrane
was operated intermittent with a cycle at 30 mins operation and 15 seconds backwash. In
backwash period, SV1 was closed and SV2 was opened.
Figure 3.7 Operating process of A-MBR
35
Figure 3.8 Photo of A-MBR system
Drain of A-MBR membrane carried out two times per day to remove coarse materials
clogging in the bottom of membrane. During drain off period, A-MBR system was
stopped operation. Manual valve V2 was opened and sludge inside of membrane was
drained of membrane. Clean water from collected tank was pumped to membrane by
backwash way to clean residue sludge in feed side of membrane. Sludge and wastewater
after clean membrane were drained off sewage.
Air from feed side of membrane passed though membrane to permeate side was released
by valve V3. Manual backwash was carried out and air was released out off membrane by
valve V3. Air in permeate side of A-MBR system was affected on output pressure and
output flow rate.
3.3.6 Membrane bioreactor (A-MBR) operational sequence
A-MBR was operated under 3 different loading rates in order to optimize the operational
parameters. Table 3.5 indicates the A-MBR operational sequence for the optimization of
A-MBR operational parameters. Basically the loading rate was altered in order to find out
the suitable organic loading to the A-MBR and the variation of permeate quality with the
loading rate.
Table 3.5 A-MBR operational sequence
Period (months)
Process
1 month
Startup period, mixed liquor from
CAS will be pumped to A-MBR tank
2 months
2 months
2 months
Optimization of loading rate
Optimization of loading rate
Optimization of loading rate
36
Loading rate
(kg COD/m3.d)
Increment of loading rate
from CAS loading rate to
1.8
1.8
4.1
5.7
Difference between CAS process of LMC IP and A-MBR of pilot scale study is
summarized following:
F/M of CAS process was 0.1±0.03 day-1. It is very low to compare with theory (0.2 – 0.5
day-1). However, HRT of CAS process is very long to compare with normal (16 h of CAS
process of LMX IP to compare with 6 -8 h). May be, CWWTP of LMX IP was designed
by extended aeration process.
F/M of CAS process was lower than A-MBR from 3 to 10 times (F/M of CAS process
was 0.077 day-1 whereas F/M of A-MBR was 0.23, 0.47 and 0.75 day-1). OLR of A-MBR
was higher than OLR of CAS process from 4 to 13 times (OLR of A-MBR was 1.8, 4.1
and 5.7 kg COD/m3.d whereas OLR of CAS process was 0.43 kg COD/m3.d). HRT of
CAS process was longer than A-MBR from 4 to 6 times (HRT of CAS process was 16 h
whereas HRT of A-MBR was 2.6, 3.1 and 4.8 h). SRT of A-MBR was longer than SRT of
CAS process nearly 2 times (SRT of A-MBR was 40 days whereas SRT of CAS process
was 22 day). This is advantages of MBR to compare with conventional activated sludge
that can lead to higher removal pollutant efficiency of MBR to compare with CAS
process.
3.3.7 Ultrafiltration tertiary treatment
The secondary sedimentation effluent was treated by UF membrane as tertiary treatment.
Secondary sedimentation effluent is pumped to the sand filtration with volume 0.18 m3.
Water passes though sand filtration came into UF membrane (dead-end) follow
mechanism inside – out. In filtration period, solenoid valve 1 (SV1) and 3 (SV3) were
opened while SV2 and SV4 were closed. Feed water came from top to bottom of UF
membrane.
Sand filtration was inserted before UF membrane as pre-treatment. Sand filtration was
high 1.2 m. Sand layer was 0.7 m. Diameter of sand filtration was 0.2 m. Total volume of
sand filtration was 0.18 m3.
Water passes though the UF membrane was stored in the permeate collection tank with
volume 100 L.
The pressure gauges and flow rate gauges are used to check the pressure loss after pass
though UF membrane module and flow rate of water pass though membrane. Figure 3.9
shows the process of UF membrane. Figure 3.10 shows photo of UF system.
The process of operation UF membrane was 10 mins for filtration and 1 min for
backwash. In backwash period, SV1 and SV3 were closed while SV2 and SV4 were
opened. Feed water was change direction from bottom to top. Clean water from storage
tank was pump to membrane from permeate. Clear water came up to down. It was
opposite direction of feed water. Concentrate of backwash was drained into the drain of
CAS system. Air was pumped into membrane in 15 seconds.
37
Figure 3.9 Process of UF membrane after CAS
Figure 3.10 Photo of UF system
3.3.8 Backwash process of A-MBR and UF membrane
Permeate collection in permeate tank was used for backwashing and chemical cleaning.
The pilot plants use automatic cleaning sequences that have been pre-programmed.
Cleaning took place on elapsed time interval. A cleaning cycle consist of flushing with
clean water (permeate). The following possibilities are available:
• Cleaning by means of backwash (BW).
• Cleaning by means of chemical enhanced backwash (CEB).
38
•
•
Cleaning by means of forward flushing. This cleaning is performed via the feed
side of membranes instead of the permeate side of the above mentioned BW and
CEB.
Cleaning by air flush (forward flushing intermittently supplied with some air at the
feed side of the membranes. (Air enhanced forward flush).
Backwash process was regularly operated to remove deposited foulants. There are three
steps for backwash process such as forward flushing, air flush, and backwash.
3.3.9 Chemical enhanced backwash (CEB)
Chemicals are used to remove any recalcitrant foulants on membrane including surface or
inside pores of membrane. They are introduced though backwash into membrane.
Chemical enhanced backwash (CEB) is operated two steps in which one is basic chemical
cleaning, and another is acid chemical cleaning. Stock chemicals are diluted at their
effective concentration for membrane cleaning before introduced into membrane.
A-MBR chemical cleaning (1 time/month):
When chemical cleaning, A-MBR system was stopped and wastewater in membrane was
drained from the bottom of membrane.
NaOCL (400 ppm) and acid citric 1% were used to clean membrane of MBR.
• NaOCL (400 ppm) was pump to membrane from permeate side and kept it in
membrane in 1 hour and then drain it out from bottom of membrane. Clean water
was pump to membrane to clean NaOCL residue out off membrane.
•
Acid citric 1% was pump to membrane and kept it in membrane 4 hour, and then
drained it out of memebrane. Clean water was pumped to membrane to clean acid
citric residue in membrane.
To prevent chemicals going to bioreactor tank, vale V5 of A-MBR system was closed
during chemical cleaning.
UF membrane chemical cleaning (1 time/2 days):
NaOH (200 ppm) was used for basic chemical cleaning step, and acid hydrochloric (HCL,
1%) was used for acid chemical cleaning step.
•
NaOH (200 ppm) was pumped to membrane and kept it in membrane 1 hour and
then drain it out off membrane.
•
Membrane is soaked about 10 minutes with clean water after basic chemical
cleaning to remove NaOH residue in membrane.
•
HCL 1% was pump to membrane and kept it in membrane 1 hour and then drain it
out by pumping clean water from permeate side as backwash. Clean water from
backwash side removed HCL residue in membrane.
39
3.4 Sampling Methods
Samples were collected at three points such as conventional effluent, UF permeate, and
MBR permeate. Figure 3.11 shows the sampling points in the system set up. This is based
on removal efficiency of A-MBR, UF membrane, and CAS effluent. Table 3.6 shows
parameters, frequency, and sampling location of CAS effluent, UF permeate, and A-MBR
permeate. All wastewater samples are collected in glass containers (added acid H2SO4 to
reduce pH less than 2 for avoiding of biodegradation when required), and then delivered
to HCMC University of Technology lab. The samples are kept in the refrigerator at
temperature low than 4 degree Celsius to preserve before analysis.
Figure 3.11 Locations of Sampling
Table 3.6 Parameters and three sampling location
Parameters
pH
Temperature
DO
TMP
MLSS
COD
BOD5
SS
Conductivity
Ni
Zn
Cr
Cd
UV254
Total Coliform
E.Coli
Frequency
3 times per week
3 times per week
3 times per week
3 times per week
Twice per week
Twice per week
One per week
Twice per week
Twice per week
One per OLR
One per OLR
One per OLR
One per OLR
Once per week
1 time per OLR
1 time per OLR
Sampling location
CAS effluent, UF permeate, A-MBR permeate
CAS, A-MBR
CAS, A-MBR
A-MBR, UF module
A-MBR
CAS effluent, A-MBR permeate, UF permeate
CAS effluent, A-MBR permeate, UF permeate
CAS effluent, A-MBR permeate, UF permeate
CAS effluent, A-MBR permeate, UF permeate
CAS effluent, A-MBR permeate, UF permeate
CAS effluent, A-MBR permeate, UF permeate
CAS effluent, A-MBR permeate, UF permeate
CAS effluent, A-MBR permeate, UF permeate
A-MBR permeate, UF permeate
CAS effluent, A-MBR permeate, UF permeate
CAS effluent, A-MBR permeate, UF permeate
3.5 Analytical parameters
Parameters are related to quality of wastewater reuse such as BOD, COD, SS, turbidity,
conductivity, heavy metals (Ni, Cr and Zn), particles, total coliforms, and E.coli were
40
measured. Dissolved organic matter related to performance of membrane was analyzed by
UV absorbance at 254 nm. Operation parameters of MBR system are influent flow, COD
loading, MLSS, HRT, SRT, F/M, temperature, and DO, TMP.
The water quality parameters given in table 3.7 were analyzed to evaluate the
performances of treatment units. Description on methods of biological water quality
parameters are given in following sections.
Total coliform and E.coli analysis
Total coliform and E.coli were analyzed by using membrane method.
Brief description of procedure
Media preparation
Medias m-ColiBlue24® was prepared before starting the experiments. Medias
m-ColiBlue24® was pour into one side of membrane.
Procedure
Wastewater samples was filtrated though membranes from other side of membrane. Then
membrane was incubated at 35oC±0.5oC in 24 hours. The appearance of blue colonies was
E.Coli and red colonies were other coliforms. Total coliform was total of blue and red
colonies.
41
Table 3.7 Analysistical parameters and method of analysis
No.
1
Parameters
Unit
pH
o
Equipment
Reference
pH measurement
pH meter
-
Thermometer
Thermometer
DO measurement
DO meter
-
Pressure
measurement
Digital pressure gauge
-
2
Temperature
3
DO
4
TMP
kPa
5
COD
mg/L
Closed Reflux,
Colormetric
UV spectroscopy
APHA et al,
2005
6
MLSS
mg/L
Dry at 103 – 105oC
Filter and Owen
APHA et al,
2005
7
BOD5
mg/L
German method
Oxitop
8
SS
9
Conductivity
10
Organic
Matters
at 254 nm
11
C
Method
mg/L
mg/L
o
APHA et al,
2005
Dry at 103 – 105 C
Filter/Owen
APHA et al,
2005
Thermometer
Conductivity meters
APHA et al,
2005
mg/L
UV/VIS
spectroscopy or
Chromatography
UV/VIS spectroscopy
or Chromatography
APHA et al,
2005
Ni
mg/L
Atomic absorption
Atomic absorption
spectrophotomer (AAS)
APHA et al,
2005
12
Cr
mg/L
Atomic absorption
(AAS)
APHA et al,
2005
13
Zn
mg/L
Atomic absorption
(AAS)
APHA et al,
2005
14
Total Coliform
MPN/100mL
Filtration method
Coliform Agar
APHA et al,
2005
15
E.coli
MPN/100mL
Filtration method
Chromocult ®
APHA et al,
2005
mS/cm
42
Chapter 4
Results and Discussion
This chapter includes the potential of industrial wastewater reuse for agriculture in HCMC
by data collection and the performances of two pilot membrane systems, namely A-MBR
and UF. A-MBR was used to treat wastewater after primary sedimentation. UF system
was used to treat wastewater after secondary sedimentation. The permeate of A-MBR and
UF was compared with the effluent of conventional activated sludge (CAS). In term of
industrial wastewater reuse for agriculture, effluent of CAS, A-MBR and UF processes
was compared with the standard for wastewater reuse.
In the HCMC study region, there is a limitation of available water sources compare to the
water demand. Water resources are depleting whereas water demand is increasing,
especially water demand for industries in HCMC. It is also indicated that industrial
wastewater was a main cause of water pollution.
4.1 Status of water resources in HCMC
At present, in HCMC main water resources consists of Dong Nai River, Sai Gon River
and groundwater are used for water supply in HCMC. Upstream Dau Tieng reservoir is
mainly used for irrigation and aquaculture. Tri An reservoir is used for hydroelectric
power plant. Rain water is used as water supply in the peri-urban area or in coastal zone
such as Can Gio with small volume for domestic activities. Water resources used for
agriculture in HCMC mainly are raw water taken from irrigation canals system of Sai Gon
and Dong Nai rivers and storm water in the rainy season. Figure 4.1 show Sai Gon and
Dong Nai river system.
The Dong canal water is expected to stop using in 2015 due to degradation of its quality
that may be generated from pollutants of agricultural and domestic activities of the NorthWest of HCMC and Tay Ninh province. Groundwater (GW) exploitation by Water Saigon
Company (WSC) and community including household, services and industries will be
limited due to degradation in terms of poor quality and water table descent (VIWASE,
2001). Water quality of Dong canal was presented in Table F2, Appendix F (HEPA, 2008,
2009 and 2010). As a result, water resources in HCM are increasingly shortage. Figure 4.2
showed the predicted water intake capacity of water resources in HCMC.
Currently, Dong Canal supplies for 7,000 ha of agricultural area in Cu Chi District. As
explained earlier, Dong canal water quality will be depleted up to significant level in
2015. Without questions, it will be impact on agricultural activities. Moreover, in dry
season, water source of Dong canal is limited that is not enough to supply for agricultural
activities. In 2010, Dong canal was exploited to supply for pipe water by Water Saigon
Company. Using water source of Dong canal for water pipe is one reason sharing water
use for tap water and irrigation which can lead to water shortage for agriculture in HCMC.
43
Dau Tieng Reservoir
Dau Tieng Dam
Thien Tan Water
Supply Plant
Tri An
Reservoir
Tri An Dam
Hoa An
Station
Dong Nai River
Sai Gon River
Binh Dien River
Long Tau
Figure 4.1 Sai Gon and Dong Nai river system
Figure 4.2 Existing and predicted water intake capacity of water resources in
HCMC
44
On the other hand, water consumption demand is increasingly year by year due to
population and economic growth. The total daily water use both demands for domestic
and industrial activities in HCMC were 1.75 million m3 in 2005, 3.6 million m3/d in 2020
and 4.1 million m3/d in 2025, respectively (Nga, 2006). Water demand for domestic from
2005 to 2015 is around 65% whereas water use for industry increases from 17% in 2005
to 23% in 2015 and water use for services reduce from 17% in 2005 to 11% to 2015.
(Table F2, Appendix F)
Figure 4.3(a) and 4.3(b) indicated water consumption demand will be over the water
intake capacity of Sai Gon and Dong Nai river system, and groundwater form 2020 to
2025 (VIWASE, 2001 and Nga, 2006). Consequence, HCMC has to find out new water
sources to supply water for sustainable development in the future. Tri An and Dau Tieng
reservoirs will be exploited for water supply in HCMC (Table F1 and F3, Appendix F).
Figure 4.3 Comparison between water intake capacity and water demand in HCMC
Moreover, Water stress index (WSI) of HCMC is estimated to be increasing. Figure 4.4
indicated that WSI in HCMC was over 10% in 2000 and it will be over 20% in 2025
(Dan, 2010). Therefore, HCMC must reduce raw water exploitation. In order to reduce
WSI from 22% to 20% and 15% in 2025, HCMC must to reduce raw water exploitation
rate 0.4 and 1.3 m3/d, respectively. To obtain this ratio, the local government should have
policies or strategic solutions for water sustainable management such as lowering
freshwater exploitation rate, increase of freshwater storage in dry season (increasing
reservoir volume, protecting forests in the upstream), using rainwater and reclaiming
wastewater. Table 4.1 shows the necessary reduction of freshwater use to meet the
desirable WSI in HCMC.
45
Figure 4.4 WSI of Sai Gon and Dong Nai rivers (Dan, 2010)
Table 4.1 The necessary reduction of freshwater use to meet the desirable WSI in
HCMC in 2025 (Dan, 2010).
Item
Desirable WSI
15%
Unit
10%
20%
Total capacity:
- For catchment area
m3/s
45
68
91
- For each person
L/capita/day
177
267
357
Water reduction HCMC (*)
L/capita/day
220
130
39
Capacity reduction to meet
m3/s
25
15
5
desirable WSI in HCMC
(*)
Note: Population of HCMC will be nearly 10 million people in 2025 (DPA HCMC,
2007)
Cause of water shortage
Main reasons which can lead to water shortage in HCMC are the pollution of water
resources, salt intrusion and over exploitation capacity of water resources.
•
Untreated wastewater of domestic, industry and hospital directly discharged into
water bodies are the main cause of pollution in water resources, especially surface
water such as Sai Gon River, canals or irrigation systems in HCMC.
Water bodies daily received 0.73 and 1 million m3/day in 2000 and 2005,
respectively from the discharge of domestic and industrial activities. Amount of
wastewater from hospitals and health care centers in HCMC is about 4,000
m3/day. Mass loading of BOD5 pollutant expected to increase from 170 ton per
day in 2000 to 380 ton per day in 2020 (Dan, 2007).
46
•
Salt intrusion from the sea to Sai Gon – Dong Nai basin and irrigation systems in
HCMC in dry season can lead to water shortage in HCMC. It usually occurs
during March to May. It has negative impact on water treatment plants, residential
areas along rivers as well as water quality for agricultural irrigation. Table 4.2
showed salinity of Hoc Mon- Binh Chanh irrigation systems.
Table 4.2 Salinity of Hoc Mon – Binh Chanh irrigation systems
Salinity (mg/L)
Irrigation in
Binh Chanh District
May, 2008
March, 2008
April, 2010
Tan Kien
1.1
3.7
6.5
Canal A
0.4
3.5
3.0
Canal B
0.6
3.1
4.5
5.5
Canal C
0.9
2.7
TCVN 6773:2000
>1
Source: HCMC irrigational exploitation and management, 2009 and 2011.
TCVN 6773:2000: Vietnamese standard of Water quality – Water quality guidelines for
irrigation (Table A5, Appendix A)
Salt concentration of Hoc Mon – Binh Chanh irrigation systems in dry season (March and
April) was very high that was over standard for agriculture due to salt intrusion. In dry
season, fresh water level in upstream (Tri An and Dau Tieng Reservior) was low that was
not enough fresh water to drain salt intrusion. Thus, in these months water of these canals
can not be used for agriculture that was a reason of water lack for agriculture during
March to April in year.
•
Rapid population growth and industrial development in HCMC are a cause of
increasing water exploitation that may lead to over capacity of water resources in
2025. Water intake from Sai Gon river, Dong Nai river and ground water is 2.15
million m3/day in 2025 (VIWASE, 2001) whereas water consumption demand is
3.6 and 4.1 million m3/day in 2020 and 2025, respectively (Nga, 2006).
In brief, water shortage has not only negative impact on sustainable development and
water consumption for human demand in near future, but also impact on agriculture in
HCMC.
4.2 Industrial water consumption in HCMC
4.2.1 Industrial status in HCMC
There are 15 existing industrial parks in HCMC by Ho Chi Minh City Export Processing
and Industrial Zones Authority (HEPZA, 2008 and Tuan, 2010) (Table F7, Appendix F).
Moreover, there are 55 existing industrial clusters which located in residential area of
HCMC. Unlike industrial parks, industrial clutters are located close together and do not
47
consist of infrastructures such as roads, greening area and drainage systems (DONRE,
2007) (Table F8, Appendix F).
There are two main water resources to supply industrial parks in HCMC comprising
ground water and treated water by Saigon Water Supply Company. 70% water supply for
industrial parks is groundwater, because the cost of water pipe by Saigon Water Supply
Company is very high around 0.225 USD/m3.
4.2.2 Water demand for industrial
As prediction, water demand for industrial parks increases from 0.24 million m3/day in
2010 to 0.38 million m3/day in 2020 (Table F9, Appendix F). The sources of water supply
for industrial include tap water, ground water or canals/rivers (HEPZA, 2008). Water
consumption demand for industrial in HCMC accounts for around 20% of total water use.
The huge amount of water consumption demand for industry in 2010 and 2020 will play a
significant role for industrial wastewater reuse in the period of water crisis in HCMC.
4.3 Water consumption for agriculture in peri-urban of HCMC
4.3.1 State of agriculture in HCMC
There are three main agricultural regions such as Hoc Mon, Cu Chi and Binh Chanh
District in Ho Chi Minh City (HCMC). According to report of agricultural economics
period 2006 to 2009 and target 2010 in HCMC by Agricultural and Rural Development
Service, total agricultural area in 2009 was 121,313 ha, comprising different kinds of
plants (Table 4.3). The rest area was used for lives stock farms. In 2009, total income
from agriculture was 38.2 million USD in which income from cultivation was 11.05
million USD.
Table 4.3 Agricultural area in HCMC in 2009 (ARDS, 2010)
Area
(ha)
27,131
10,000
2,000
1,792
3,500
11,000
1,900
3,400
38,860
Plant
Rice
Vegetable
Maize (corn)
Sugar cane
Rubber
Fruit trees
Flower and bonsai
Grass field
Forest
48
Agricultural activities in Cu Chi
Dong Canal, Cu Chi District
Agricultural activities and
irrigation system in Hoc Mon
Agricultural area and irrigation system in Binh Chanh
Figure 4.5 Map of agricultural area and irrigation systems in HCMC
There are three main irrigations such as Dong Canal, Hoc Mon – Binh Chanh canals, and
Sai Gon River –Cu Chi in HCMC in which Dong canal supplies water for 26,380 ha, Hoc
Mon – Binh Chanh canals supplies water for 23,800 ha, and Sai Gon River – Cu Chi
supplies water for 4,500 ha. The water quality of irrigation systems was deteriorating.
Hence this can not use for irrigation due to high pollution and salinity in dry season this
can lead to lack of water for crops during their growth period. Figure 4.5 show the map of
agricultural activities and irrigation systems in Binh Chanh, Hoc Mon and Cu Chi
District.
Dong canal is irrigation systems which are supply water for agriculture in Cu Chi District.
Upstream of Dong canal is Dau Tieng reservoir in Tay Ninh province.
Hoc Mon – Binh Chanh irrigation system includes main 8 channels such as Thay Cai
canal, An Ha canal, An Ha – C canal, region canal, Long An canal, A canal, B canal and
C canal. It was designed to control salt intrusion and water supply for agriculture without
49
the function of reducing pollution. These canal systems are connected to Binh Dien River.
Water is got into these irrigation systems in high tide from Binh Dien River. Now it was
over its capacity due to using for pollution control. That leads to negative impact on its
irrigation for agriculture.
Sai Gon River – Cu Chi supplies water for agricultural area along Sai Gon River to Cu
Chi District and rain water was used for agriculture in rain season.
4.3.2 Estimate water demand for agriculture
Base on agricultural area in HCMC and water demand for crops, annual water demand for
agriculture in HCMC can be calculated as follows. Table 4.4 shows the amount of water
demand for agriculture in HCMC.
Table 4.4 Water demand for agriculture in HCMC
Area (a)
Standard (b)
Crop (c)
Water demand
(ha)
(mm/ha)
(million m3/year)
per year
Rice
27,131
450 - 700
2
244 – 380
Vegetable
10,000
350 - 500
4
140 – 200
Sugarcane
1,792
1,500 – 2,500
1
26 – 45
Maize
2,000
500 – 800
1
10 – 16
Fruit trees
11,000
900 – 1,200
1
99 – 132
Total
519 – 773
(a)
Agricultural area: Agricultural and Rural Development Service, 2010.
(b)
Standard: Crop water need, FAO (Table C2, Appendix C)
1 mm/ha = 0.001 m * 10,000 m2 = 10 m3/ha
(c)
Crop per year from interview of farmers
Crop
Amount of water demand for main crops including rice, vegetable, sugarcane, maize
(corn) and fruit trees in HCMC is 519 to 773 million m3/year. Beside that there are large
areas of water morning glory, water mimosa etc. Thus, water demand for agriculture in
HCMC is very large.
4.4 Impact of untreated industrial wastewater in HCMC
Only 6 out of 14 IPs in HCMC have central wastewater treatment plant which a mount of
treated wastewater was 15,000 m3/day that accounts 46% of total industrial wastewater.
The rest (17,500 m3/d) is directly discharging into water bodies in HCMC. This lead to
many negative impact on environment, aquatic systems and human. Moreover, the 62% of
wastewater treatment plants dose not meet treated effluent up to the Vietnamese standard
for industrial wastewater discharge (HEPZA, 2008). Figure 4.6 shows the schematic
diagram of route of potential water resources pollution risk from activities of IPs.
50
Pipe water
from WSC
Groundwater
Central WTP in IP
industries in IPs
Wastewater
Wastewater
Not connect into
wastewater
drainage
system of IPs
Wastewater drainage
system of IPs
Leachate
In – situ pretreatment plant of
industry
Central WWTP
Surface receiving water
(Dongnai – Saigon Rivers, canals)
Infiltration
Groundwater
Figure 4.6 Schematic diagram of route of potential water resources pollution risk
from activities of IPs
4.4.1 Impact on surface water
Water bodies in HCMC received the huge amount of polluted water from industrial parks
that exceeds their self-purification capacity. As a result, surface water quality reduces that
does not only use for any purpose, but also has impact on environment. Analysis results of
surface water sources in HCMC showed that there were parameters in terms of organic
matter, nutrient, heavy metals and pathogens that were over Vietnamese surface water
quality standard (TCVN 5942:2005) at level B which could not use for agriculture,
irrigation or navigation. Receiving the effluents of industrial parks in HCMC was
presented in table F5, Appendix F (HEPZA, 2008). Therefore, water quality of these
canals can not directly use for agriculture or irrigation.
Canal systems of HCMC have been heavily polluted with dark color and the emission of
bad smell, especially at low tide (Figure F1, 2, 3, 4, 5, 6, 7, 8, 9, Appendix F). Base on
polluted wastewater discharging into water bodies by map in HCMC, it is predicted that
51
water sources around IP’s areas which are vulnerable areas will be increasingly polluted
and spread out, if it is not good about wastewater management and control pollution.
Figure 4.7 shows the prediction of water surface pollution in HCMC and area of this
study.
Cu Chi District
Tran Quang Co canal
District 12
District 12
Hoc Mon District
Binh Chanh District
Canal B, Binh Chanh
Figure 4.7 Map of potential pollution streams in HCMC and study area
4.4.2 Impact on ground water
Over exploitation of ground water for industry and agriculture in HCMC lead to depletion
of groundwater source. The contamination of polluted wastewater from industries further
deteriorated the quality of ground water. Monitoring results of ground water in HCMC
52
show that groundwater has continuously reduced due to recharging with polluted surface
water. Pleistocene aquifer of ground water was recharged about 39% and 8.5% of total
fresh water from surface water such as storm-water and Sai Gon river water, respectively
(Nga, 2005) (Table F4, Appendix F). Thus, polluted surface water has high risk pollution
for ground water.
Total organic carbon (TOC) of groundwater in some places was higher than 1.5 to 2 times
compared to previous years (Table F10, Appendix F). Heavy metals such as Zn, Pb, Cu
and Cd were also found in ground water of some places. They are over Vietnamese
environmental standard (TCVN 5944-1995) (Table F11, Appendix F). Therefore, use of
ground water for domestic, industrial and agricultural activities in recent may have
negative impact on human health due to direct absorption or accumulation of toxics on
food chain such as heavy metals, organic materials.
At the moment, it is not much concern of general public in HCMC. There should have
more studies and awareness program on this issue.
4.4.3 Farmers’ perspectives
Research on wastewater impact on agriculture in HCMC was not reported much. Data of
the interview of farmers were summarized (Figure 4.8).
•
All the farmers who were interviewed thought that industrial wastewater is the
main cause of water pollution.
•
80% of interviewed farmers pointed that water of irrigation systems was polluted.
Hence, it could not use for irrigation activities. However, twenty percent of them
said that water surface source such as Lon River and An Ha canal are not much
polluted (Figure F20 and F21, Appendix F).
•
90% of interviewed farmers claimed that water surface pollution was a cause of
water lack for agriculture. It could not use for their farms, so they only use rain
water, ground water or fresh water from upstream as Dau Tieng and Tri An
reservoirs. 10% of them believed that wastewater was good for their farms in
terms of water morning glory and water mimosa.
•
70% of interviewed farmers claimed that water pollution reduced their crop yield
such as crop yield of rice and vegetable. However, 30% of them think that it was
good for cultivating water morning glory, water mimosa and duckweed.
•
All the interviewed farmers believed that water pollution had impact on their crop
quality. Hence, it could lead to low price and yield. Most of them also thought that
industrial wastewater has many negative impacts on their health such as itches and
scabies. They had no idea about other diseases such as diarrhea, conjunctivitis,
cholera, etc. They also claimed that industrial wastewater should be treated before
discharge into water bodies.
53
•
Most of farmers do not protect their health by wearing of protected cloths. Excepts
farmers who grew the water morning glory, duckweed and water mimosa because
they often exposure with polluted water (Figure G1, G2 and G3, Appendix G).
In brief, untreated industrial wastewater has close relationship with agricultural activities
in HCMC such as pollution of irrigation systems, negative impact on crop yield and
quality, and farmer health.
Figure 4.8 The impact of wastewater on agricultural activities based on farmers’
perception
Combination of available documents and the results of interviewed farmers (Table D1 and
D2, Appendix D) strongly pointed the relationship between wastewater impact on
agriculture in HCMC in this study. These results were shown the relationship between
industrial wastewater and agricultural activities such as lack of water for agriculture,
impact on yield and quality of plants, agricultural soil, farmer health, farmer income and
community conflict.
Lack of water for agriculture
From survey, there are two main reasons of water lack fro agricultural activities in periurban HCMC. They are polluted water surface and salt intrusion into irrigation system,
especially in dry season. Main water sources used for agricultural activities are rain water.
Ground water and fresh water from upstream such as Dau Tieng and Tri An reservoirs. As
a result, it is the lack of water for agricultural activities in peri-urban area. Agricultural
activities are mainly on rain season. Many rice areas are followed on dry season due to no
fresh water supply for agricultural activities (Figure F14 and F15, Appendix F).
Impact on yield and quality of plant
Lack of water or use of water pollution for agriculture in HCMC is a main cause of
reducing agricultural yield and quality.
54
Interviewed farmers in Le Minh Xuan Ward, Binh Chanh District and Binh My Ward, Cu
Chi District claimed that rice yield reduced from 4.5 tons per hectare to 3.5 or 4 tons per
hectare in Le Minh Xuan Ward. The quality of rice was also not good (Figure F23). To
compare rice yield in Le Minh Ward and Tan Nhut Ward, Binh Chanh District showed
that rice yield in Le Minh Xuan Ward was about from 3.5 to 4 tons/ha whereas rice yield
in Tan Nhut Ward was about 4.5 tons/ha (Figure 4.9 (a)). Water supply for rice farms in
Le Minh Xuan Ward is mainly by irrigation systems of canal B (Figure F4, Appendix F)
which was heavy pollution whereas water supply for agriculture in Tan Nhut Ward is
Xang River which is not polluted (Figure F20, Appendix F). Farmers in Tan Tao Ward
claimed that rice yield cultivated in rain season (from June to August) was higher than
rice yield in next crop (from September to December) because of less rain water in this
crop (Figure 4.9(b)). Farmers in Binh My Ward, Cu Chi District also believed that
vegetable yield reduced from 6-10 tons/ha to 3-4 tons/ha due to impact of water pollution
by untreated industrial wastewater of factories around there.
Figure 4.9 (a): Rice yield in Le Minh Xuan
and Tan Nhut Ward, Binh Chanh District
Figure 4.9(b): Rice yield in Summer-Autumn
Crop and Winter –Spring Crop, in Tan Tan
Ward
Moreover, interviewed farmers in Le Minh Xuan Ward, Binh Chanh District believed that
occurring yellow color on rice leaves was a cause of water pollution. This phenomenon
did not happen before water pollution on canal because of industry (Figure F22, Appendix
F). This also occurred on rice farms of Mr.Anh who tried to cultivate his rice on dry
season by using directly water pollution form B canal in Le Minh Xuan Ward, Binh
Chanh District.
Use of water pollution for agriculture in HCMC was a cause of accumulation heavy
metals on vegetable. Analysis results by An, 2007 showed that Pb concentration in some
kinds of vegetable in many places in HCMC were over Vietnamese health standard of
health Ministry. Table 4.5 shows Pb concentration in vegetable that grew in HCMC.
55
Table 4.5 Pb concentration in vegetable grown in HCMC
No
1
2
3
4
5
6
7
8
9
10
Place
Vegetable
(Ward and District)
Tan Thoi Nhi, Hoc Mon
Red amaranth
Tan Thoi Nhi, Hoc Mon
Basil
Tan Thoi Nhi, Hoc Mon
Spinach
Dong Thanh, Hoc Mon
Chili spinach
Thoi Tam Thon, Hoc Mon
Lettuce
Phuoc Thanh, Cu Chi
Spinach
Phuoc Thanh, Cu Chi
Basil
Qui Duc, Binh Chanh
Spinach
Binh Chanh, Binh Chanh
Perilla
Da Phuoc, Binh Chanh
Water morning glory
10TCN 442-2001, 867/1998/QĐ-BYT
Pb concentration
(mg/kg)
0.226
0.257
0.264
0.479
0.705
0.282
0.205
0,601
0.409
0.719
0.200
Source: An, 2007
In brief, farmers in peri-urban of HCMC have to use wastewater for their farms because
they have no choice. It is unique water resources for their farms although it is heavy
pollution and has many negative impact on farmers, reducing quantity and quality of
agriculture products. Water pollution is also a cause of heavy metal accumulation on
vegetable.
Impact on agricultural soil
According to monitoring station and South environmental soil analysis: ”Report the
monitoring soil pollution by waste water from industrial production and urban living Nha Be - Binh Chanh and Cu Chi District in HCMC, 2001 - 2005”, area of agricultural
soil was increasingly abandoned due to soil pollution, especially heavy metals
accumulation. Soil pollution was caused using wastewater for watering and intrusion of
wastewater into farm due to high tide. Soil pollution had negative impact on yield and
quality of products. Heavy metals accumulation in soil in Nha Be – Binh Chanh region
was shown following:
Concentration of Cr in soil in 2004 and 2005 was from 57.7 to 106.2 mg/kg and from
42.18 to 63.50 mg/kg, respectively. It was over the standard Cr Canadian CCME 1997 (64
mg/kg) and higher than the Cr concentration in soil in 2001, 2002 and 2003 (Figure F26,
Appendix F).
Cu concentration accumulation in soil has trend to increase from 2001 to 2004. Cu
concentration in soil in 2005 ranged from 13.93 mg/kg to 22.15 mg/kg that was not
different in 2004. Cu concentration still meet Vietnamese standard (TCVN 7209-2002)
for safety limited of agricultural soil (Figure F27, Appendix F).
Concentration of As in soil was lower than Vietnamese standard for agricultural soil (12
mg/kg). However, trend of As accumulation in soil increased, especially high increasing
in 2005. As concentration in soil was 2.2 to 4.8 mg/kg in 2004 compared with 0.006 and
0.037 mg/kg in 2001 (Figure F28, Appendix F).
56
Similarly, Hg concentration in sagricultural soil in Nha Be-Binh Chanh still meet standard
(6.6 mg/kg) for agricultural soil. Hg concentration ranged from 0.1 to 0.11 mg/kg. But Hg
concentration also has trend to increasing accumulation in soil from 2001 to 2004 (Figure
F29, Appendix F).
Reprot of Le Huy Ba (2009) on the impact of heavy metals in soil on plants showed that
Cd2+ at concentration 1 ppm stimulated the activity of broccoli, but at 100 ppm dominated
the growth of broccoli. Cd2+ at 0.1 ppm stimulated the activity of rice and dominated at
concentration 30 – 100 ppm. Concentration of Hg2+ at 0.1 ppm stimulated the activity of
broccoli and stimulated the rice activity at concentration 10 ppm, but concentration 100
ppm of Hg2+ dominated the height of rice. Concentration of Pb2+ at 10 ppm stimulated the
broccoli, but dominated broccoli’s growth at 1,000 ppm.
Survey on farmers in Tan Tao Ward showed that there is the fallow of many rice areas
due to soil pollution or in some places, rice soil has to change in use of duckweed growth
(Figure F24 and F25, Appendix F).
In brief, trend of heavy metal accumulation from industrial wastewater on agricultural soil
is increasing. Heavy metals can directly affect the growth of plants or accumulate on crop
products.
4.4.4 Impact on human health
Industrial wastewater compositions such as organic matters, heavy metals, pathogens and
odor have high risk potential to human health. Thus, untreated wastewater with high
concentration of pollutants has high risk potential to human health compared to treated
wastewater. General relationship between wastewater and diseases are dermatosis,
digestive trouble and respiration. Industrial wastewater of Tan Thoi Hiep IP with
wastewater treatment plant (WWTP) had lower risk quotient (RQ) to human health such
as dermatosis and digestive trouble compared to wastewater of Vinh Loc IP without
WWTP (Tran, 2009). Table 4.6 shows the risk matrix of Tan Thoi Hiep IP and Vinh Loc
IP on diseases of dermatosis and digestive trouble. This study showed that treated
industrial wastewater is less risk potential for human health than untreated wastewater.
Figure 4.10 shows the diagram of risk quotient of different compositions of Tan Thoi
Hiep IP and Vinh Loc IP in HCMC (Tran, 2009).
4.5 Characteristic of Feed wastewater to A-MBR and UF
As mentioned in section of 3.3.1 the wastewater from LMX IP comes from different
factories. Feed wastewater was very complex due to combination of many different
productions of factories. Feed wastewater of A-MBR is the effluent of primary
sedimentation tank of CWWTP, while the feed for of UF is the effluent of secondary
sedimentation tank of CWWTP. The characteristics of feed wastewater are presented in
Table 4.6. Feed water for A-MBR from CWWTP of LMX IP was pre-treated by some
process such as coagulation, flocculation and setting at primary sedimentation tank as
well as removing coarse materials by screen 1mm. Feed water of UF system was treated
by CAS process before disinfection step as well as removing SS by sand filtration which
inserted before UF system.
57
Table 4.6 Characteristics of feed wastewater
Parameter
Unit
A-MBR (n=39)
UF (n= 39)
7.6 ± 0.3
4.74 ± 0.55
498 ± 294
178 ± 34
3.7 ± 2.25
61 ± 36
743 ± 570
2.4 x106
1.4 x104
0.59
0.29
nd
nd
7.5 ± 0.4
4.24 ± 0.52
86 ± 26
17±1.5
0.8 ± 0.13
50 ± 81.3
163 ± 68
4.9 x103
1.4 x103
0.22
0.18
nd
nd
pH
Conductivity
(mS/cm)
COD
(mg/L)
BOD5
(mg/L)
UVA254
(m-1)
SS
(mg/L)
Color
(Pt-Co)
Total Coliform
(MPN/100mL)
E. coli
(MPN/100mL)
Zn
(mg/L)
Ni
(mg/L)
Cr
(mg/L)
Cd
(mg/L)
Note: mean value ± standard deviation
nd: not detected
Figure 4.10 show the variation of feed COD and color during experimental period. Feed
COD was very high at period from November to January to compare with other months.
Feed COD of wastewater from October to November (rain season) was lowest to compare
other months. It may be a cause of diluted wastewater by rain water. Similarly, feed color
was lowest from October to November and highest from November to December.
Figure 4.11 show the variation of feed conductivity during experimental period. Feed
conductivity was about 4.74±0.55 mS/cm. Feed conductivity was very high. It may be a
cause of chemical use in the production of factories.
Figure 4.10 Variation of feed COD and color during operating period
58
Figure 4.11 Variation of feed conductivity during operating period
4.6 Operating condition of A-MBR and CAS process.
4.6.1 Seed sludge acclimatization
Seed sludge was collected from bioreactor tank of CWWTP of Le Minh Xuan IP.
Acclimation of seed sludge was carried out for one month period.
4.6.2 Organic loading rate and F/M ratio
Operation conditions of A-MBR and CAS were shown in Table 4.7. It was referred to
method on section 3.3.4. It was not the same with initial calculation for OLR. The reason
of changing COD concentration liked this, may be after Vietnamese Tet’s holiday during
the time for operation with OLR3 for two months, the factories with discharging high
COD concentration such as food products were not much production which can lead to
low COD concentration influent. Detail data calculation was presented on Appendix J.
Table 4.7 Operating conditions of CAS and A-MBR
Parameters
F/M
OLR
HRT
SRT
MLSS
pH
DO
Temp
Unit
CAS
day-1
kg COD/m3.d
hour
day
mg/L
mg/L
o
C
0.077
0.43
19.6
22.5
6,300
7.0-8.0
2.5
28-38
OLR1
0.23
1.8
4.2
40
6,996±523
6.58-8.22
6.09±0.99
40±0.5
59
A-MBR
OLR2
0.75
5.7
2.8
40
7,554±574
7.45-8.23
4.95±0.41
39±1
OLR3
0.47
4.1
2.6
40
8,737±229
7.43-8.2
4.73±0.22
40±0.6
4.6.3 pH, DO, Temperature and MLSS in the aeration tank
pH in the aeration tank of A-MBR was ranged from 7.67 ± 0.45 (n=50) which were
suitable for microorganisms growth. pH was steady in neutral range because of good
neutralization after settling at primary sedimentation tank.
The mean DO concentration in the aeration tank at OLR1 was 6.09 ± 0.99 mg/L (n=50).
These values were higher due to high capacity of air pump and air supply for membrane
of concentrate (sludge return). The mean DO concentration in the aeration tank at OLR2
and OLR3 were 4.95±0.41 and 4.73±0.22 mg/L, respectively because of changing a new
air pump with low capacity (30 L/min) to replace old one (80 L/min). This purpose was
reach to optimum energy consumption for A-MBR process. However, for further study, it
might be better to use a adjustable aeration system to maintain the DO concentration.
The mean temperature of mixed liquor in the aeration tank was 40 ± 2 oC (n=50) (data
detail in Table J1 and J2, Appendix J). High temperature may be due to high feed flow
rate (45-60 L/min) into the membranes and small aeration tank. In order to attain high
flow rate, high feed pump was used. It may occur temperature exchange between feed
water and feed pump that can lead to increasing temperature of feed water. High
temperature of aeration tank was due to high temperature of feed water circulation to
aeration tank. However, the mean operating temperature of A-MBR system was lower
than allowable that of Norit membrane (max 45 oC). Detail data of pH, DO and
temperature of aeration tank were presented in Table J1 and J2, Appendix J. Temperature
in the aeration tank of A-MBR system was higher than temperature of CAS process.
MLSS of OLR1 had trend to reduce during operating period from 7,050 mg/L to 6,450
mg/L because at OLR1, feed COD concentration was low around 303±100 mg/L that was
not enough nutrients to support for microorganisms growing. As a result, MLSS
concentration in aeration tank reduced. On the other hand, MLSS of OLR2 was increasing
during operating time from 7,240 to 8,700 mg/L. Although OLR1 and OLR2 were
operated with same volume of aeration tank (0.22 m3), OLR2 was higher COD
concentration than OLR1. Average COD concentration of OLR2 was 724 mg/L to
compare with 303 mg/L of OLR1 and flux of OLR2 was 45 L/m2.h to compare with 30
L/m2.h of OLR1. Similarly, MLSS of OLR3 had trend increasing from 8,650 mg/L to
9,050 mg/L during operating period. MLSS concentration of OLR3 had increasing trend
compare with MLSS concentration of OLR2. During the change from OLR2 to OLR3, little
excess sludge was removed from the tank. Input steady from sludge removal has to be
done to keep it at same range. It can be due to small volume of aeration tank at OLR3
(0.19 m3) to compare with OLR2 (0.22 m3). Figure 4.12 shows the variation of MLSS of
three OLR during operating period. Detail data of MLSS was shown in Table J3,
Appendix J.
60
Figure 4.12 MLSS variation of OLR1, OLR2 and OLR3 during operating period
4.7 Effect quality of membrane systems and comparison with conventional activated
sludge and standard
4.7.1 Treated water quality
pH
pH treated water quality of CAS, A-MBR and UF processes as presented in Figure 4.13
vary with time. In general, pH value effluent of three systems met Vietnamese standard
for industrial wastewater discharge into water bodies (Table A1, Appendix A). pH treated
water quality of CAS, A-MBR and UF processes is suitable for reuse of agricultural
purpose. These pH value of treated water quality vary in neutral range that is not much
effect on structure of soil and suitable for plant growth. Detail data of pH value variation
show in Table L1, Appendix L.
61
OLR1
OLR2
OLR3
Figure 4.13 Variation of pH value of CAS, A-MBR and UF processes during
operating period
COD removal performance
Figure 4.14 indicates the variation of effluent COD from CAS, A-MBR and UF processes
during the period. At the beginning of OLR1 effluent COD of CAS, A-MBR and UF
processes were lower than 100 mg/L which meet Vietnamese standard for industrial
wastewater discharge into water bodies. During this period (rain season from October to
middle of November), effluent COD of CAS process always meets Vietnamese standard
for industrial wastewater discharge at level B (Table A1, Appendix A). It can be
explained that effluent COD of CAS process was diluted by rain water that can lead to
reduce effluent COD of CAS process. However, at OLR2 and OLR3 of A-MBR process of
this study (dry season from December, 2010 to March, 2011), the effluent COD of CAS
process in some days did not meet the standard. It varies from 116 mg/L to 150 mg/L.
Detail data of COD effluent of CAS, A-MBR and UF processes was shown on Table L2,
Appendix L. On the other hand, treated water quality of A-MBR and UF always meet
standard to compare with CAS process. The results indicate that higher performance of
effluent COD of A-MBR and UF membrane process than CAS process.
The treated water quality of two membrane processes can be reused for agricultural
purpose with COD parameter. However, COD effluent of CAS process has to be careful
to directly reuse for agriculture due over the standard in some days of dry season. High
effluent COD discharge into irrigation systems can lead to depletion of oxygen due to
biological decomposition. Therefore, low moderate COD concentration of membrane
processes is beneficial for irrigation systems.
62
OLR1
OLR2
OLR3
Figure 4.14 Variation of effluent COD of CAS, A-MBR and UF processes during
operating period
Figure 4.15 Average effluent COD of CAS, A-MBR and UF processes
BOD5 removal performance
Average BOD5 effluents of CAS process and permeate A-MBR and UF processes were
18, 13 and 15 mg/L, respectively. All effluent of CAS, A-MBR and UF processes meet
Vietnamese standard for industrial wastewater discharge into water bodies. BOD5
removal efficiency of CAS, A-MBR and CAS+UF processes was 90, 92 and 91%,
respectively. This result indicates that BOD5 removal efficiency of A-MBR is better than
CAS process. BOD5 removal efficiency by biodegradation in aeration tank of CAS
63
process and A-MBR process is good. Detail data of BOD5 was shows on Table L9,
Appendix L. Figure 4.16 show average effluent BOD5 of CAS, A-MBR and UF
processes.
Effluent BOD5 is low moderate concentration that does not exceed amount cause problem
for irrigation system due to depletion of oxygen by biological decomposition. Effluent
BOD5 of CAS, A-MBR and UF processes can reuse for agricultural purpose.
Figure 4.16 Average effluent BOD5 of CAS, A-MBR and UF processes
SS removal performance
Figure 4.17 indicate the variation of effluent SS of CAS, A-MBR and UF processes. All
effluent SS met Vietnamese standard for industrial wastewater discharge into water
bodies. However, effluent SS of CAS is very high that is over Vietnamese standard in
some days. Samples were taken on day of UF membrane fouling due to high effluent SS
of CAS process. Effluent SS of CAS process on these days was 159, 215 and 246 mg/L
(Table 4.18). High effluent SS of CAS process may be due to over load capacity of
CWWTP of LMX IP.
Average of effluent SS of CAS process was 50 mg/L whereas effluent SS of two
membrane processes was not detected. This is agreement with many recent researches on
membrane that effluent SS of membrane is very low or not detected. Separation of SS
concentration in water by mechanism of membrane pore side is the result of undetected
SS at effluent of two membranes. Removal SS by membrane can take many advantages
such as improving COD removal or nutrient removal etc, especially improving heavy
metals removal due to absorption of heavy metals on suspended solid (Bolzonella. D., et
al. (2010)). SS removal efficiency by membrane is very high. It is nearly 100% that can
lead to meet many restricted standard in the word due to free solid permeate.
Nevertheless, effluent SS of CAS process was from 10 mg/L to 350 mg/L during
operating period. Figure 4.18 show average effluent SS of CAS, A-MBR and UF
processes. Detail data of effluent SS of CAS, A-MBR and UF processes were presented
on Table L4, Appendix L.
Effluent SS of membrane processes is not detected that is high potential to reuse for
agricultural activities. Effluent SS of CAS process also meet standard for industrial
64
wastewater reuse in agriculture. However, it is very high in some days that is over
standard.
Figure 4.17 Variation effluent SS of CAS, A-MBR and UF processes during
operating period
Figure 4.18 Average effluent SS of CAS, A-MBR and UF processes
Conductivity removal performance
Figure 4.19 indicate that the variation of effluent conductivity of CAS, A-MBR and UF
processes and feed water was often higher than 4 mS/cm during experimental period. It
was usually over FAO guideline for interpretation of water quality for irrigation (0.7 – 3
mS/cm). However, in some day the effluent conductivity of A-MBR process meet FAO
65
guideline to compare with other processes. The variation may be dependence on the
components of wastewater characteristic which can cause high conductivity. These
components may be highly removed by A-MBR due to taking advantage gravitational
classifier in aeration tank (high MLSS) and separation by UF membrane to compare with
single CAS process and UF process.
OLR1
OLR2
OLR3
Figure 4.19 Variation of effluent conductivity of CAS, A-MBR and UF processes
during operating period
Average conductivity of CAS, A-MBR and UF process was 4.23, 3.85 and 4.04 mS/cm,
respectively (Figure 4.20). Conductivity characteristic of Le Minh Xuan IP was difficult
to remove by CAS, A-MBR and UF process.
High effluent conductivity of CAS, A-MBR and UF processes could damage crop. High
effluent conductivity of CAS, A-MBR and UF processes may be due to high Chlorine and
Sodium which is toxic to some crops, especially, permeability problems of crop due to
extensive sodium. As a result, effluent conductivity of CAS, A-MBR and UF processes
could not directly reuse for agriculture base on FAO guideline. Therefore, it should find
out the cause of high influent conductivity of wastewater. It should be applied pretreatment or post-treatment of wastewater to meet FAO guideline for wastewater reuse in
agriculture in term of conductivity.
To find out the cause of high conductivity of wastewater in LMX IP, wastewater of
factories in IP was conducted by the measurement of conductivity at output of drain of
factories. The result of conductivity measurement showed that there are four main groups
of production, causing high conductivity of wastewater in LMX IP. That is tanning,
pesticide, planting and food production. Detail data of conductivity of factories in LMC
IP was presented in Table M1, Appendix M.
66
Figure 4.20 Average effluent conductivity of CAS, A-MBR and UF processes and
feed water
Color removal performance
Figure 4.21 indicate the variation of effluent color of CAS, A-MBR and UF processes
during operating period. Effluent Color of CAS, A-MBR and UF processes is still higher
than Vietnamese standard for industrial wastewater discharge into water bodies. However,
effluent color of A-MBR process had met standard in some days whereas CAS process
and UF did not meet standard during the experimental period. Normally, effluent color AMBR was always less than CAS and UF process. Detail data was presented on Table L5,
Appendix L.
OLR1
OLR2
OLR3
Figure 4.21 Variation of color effluent of CAS, A-MBR and UF processes during
operating period
67
Figure 4.22 indicate the average color value of feed water and effluent of CAS, A-MBR
and UF processes. Feed color was high around 743 Pt-Co, but effluent color of CAS, AMBR and UF process was 162, 112 and 132 Pt-Co, respectively. These results indicated
that color removal efficiency of A-MBR was higher than combination of CAS process
and UF process. Color removal efficiency of CAS, A-MBR and UF processes was 67.3,
73.7 and 15.1%, respectively. Low color removal efficiency of UF process after CAS
process could be presence of soluble or low molecular weight organics after
biodegradation in aeration tank that can pass though UF membrane.
High effluent color of CAS, A-MBR and UF did not meet standard for industrial
wastewater discharge into water bodies at level B. In this case, pre-treatment or posttreatment must be applied to reach a purpose of wastewater reuse for agriculture. To find
out the reason of high color of wastewater in LMX IP, it was found that the main cause of
high color was textile and dying production. Color measurement of output from some
factories was presented on Table M1, Appendix M. There are more than 20 textile and
dying factories in LMX IP which is discharge a huge amount of wastewater per day.
According to report of Thanh, 2009, amount of water consumption by textile and dying in
LMX IP account for 27.1%. Therefore, color of wastewater in LMX IP could be main
cause of textile and dying production.
Color characteristic of effluent was removed by chlorine. Small test was tested to treat
color effluent by three different chemicals including Cl2, NaOH and HCl. It was found
that color disappeared with adding Cl2 and had precipitation with yellow color while color
also became light with brown precipitation. However, color did not disappear with adding
HCL and no precipitation. Figure O1 on appendix O showed the photo of result after
adding chemical into effluent of CAS process. This may be the way for further study to
remove color effluent of wastewater in LMX IP.
Figure 4.22 Average feed water color and effluent color of CAS, A-MBR and UF
processes
68
UV254
Figure 4.23 indicate the variation of UV absorbance at 254 nm of A-MBR and UF process
during experimental period. Effluent UV254 of A-MBR and UF processes was 0.772 and
0.826 m-1. The UV 254 removal of UF system after CAS process was 5.41%. This result
agrees with the result of Decarolis. J., et al. (2001). UV254 rejection by hollow fiber
UF membrane (dead-end) which was used as tertiary wastewater was 4.1%.
OLR1
OLR2
OLR3
Figure 4.23 Variation of UV254 permeate A-MBR and UF processes
during operating period
Heavy metals removal performance
Four heavy metals were analyzed in this study were Zn, Ni, Cr and Cd. Cr and Cd did not
find in wastewater of LMX IP during the experimental period. Effluent Zn of CAS, AMBR and UF processes was 0.28, 0.25 and 0.27 mg/L, respectively. Effluent Ni of CAS,
A-MBR and UF processes was 0.96, 0.15 and 0.6 mg/L, respectively. Detail data was
presented on Table L10, Appendix L.
Four heavy metals meet Vietnamese standard for industrial wastewater discharge at level
B such as Zn = 3 mg/L, Ni = 0.5 mg/L, Cr = 1 mg/L and Cd = 0.01 mg/L. Therefore,
effluent of CAS, A-MBR and UF processes can directly reuse for agriculture in terms of
heavy metals for Zn, Ni, Cr and Cd. Low effluent heavy metals of CAS, A-MBR and UF
may have positive effects on plant growth at appropriated concentration and not much
impact on heavy metal accumulation in soil.
Pathogen removal performance
Effluent total coliform of A-MBR and UF process was from 7.8 – 1.3x102 and 2.0 –
2.2x101 MPN/100 mL, respectively. Effluent total coliform of UF process was lower than
A-MBR process due to smaller pore sizes of UF membrane than A-MBR, 0.03 µm to
compare with 0.05 µm. Effluent E.coli of two membrane processes was less than 1.8
69
MPN/100 mL or not dectected. This result agrees with Bolzonella. D., et al (2010). Total
coliform ranged from 0 to 240 MPN/100 mL as well as E.coli was not found in effluent of
membrane (MBR) (Bolzonella. D., et al. (2010)). Effluent total coliform and E.coli of
CAS process was 1.6x103-1.7x104 and 1.7x102-1.4x103 MPN/100 mL, respectively. They
were over Vietnamese standard for industrial wastewater discharge at level B, total
coliform (5x103 MPN/100 mL) and WHO guideline for E.coli (10x102 MPN/100/mL).
Detail data was presented on table L10, appendix L.
High removal efficiency of microorganisms by two membrane systems had important
implication for wastewater reclamation and reuse. That can directly reuse for agriculture
in term of microorganisms. It is no need to do a disinfection step, whereas CAS effluent
have to do one more disinfection step because its effluent did not often meet standard for
wastewater reuse for agriculture in term of microorganisms. High effluent pathogenic
organisms of CAS process can lead to high risk to farmers’ health due to direct expose
with pathogens.
4.7.2 Quality and reuse option
In general, effluent pH, SS, BOD5, COD, heavy metals such as Zn, Ni, Cr and Cd as well
as total coliform and E.coli of CAS, A-MBR and UF processes meet standard for
industrial wastewater discharge or reuse for agriculture. However, effluent COD and SS
of CAS process did not meet standard in some days. Therefore, effluent COD anf SS of
CAS process can be not strongly accepted for industrial wastewater discharge into water
bodies base on QCVN 24/2009/BTNMT and other guidelines.
Effluent color and conductivity of CAS, A-MBR and UF processes did not meet the
standard for industrial wastewater discharge or reuse for agriculture. Therefore,
wastewater of LMX IP should be treated these parameters before discharge into water
bodies or reuse for agriculture. Pre- treatment or post-treatment should be applied to
increase quality of effluent for agricultural reuse in peri-urban of HCMC. Moreover, to
control and manage the cause of high color and conductivity of wastewater from factories
should be study to reduce high color and conductivity of wastewater from factories before
collected wastewater to CWWTP of LMC IP.
Comparison efficiency of CAS, A-MBR and UF processes
Table 4.8 indicates the effluent quality of CAS, A-MBR and UF processes to compare
with standard for industrial wastewater discharge into water bodies or reuse for
agriculture. It indicates that the treated water quality of A-MBR process was higher than
CAS process and UF process as tertiary wastewater treatment after CAS process.
Therefore, A-MBR process has high potential to apply for treated industrial wastewater in
term of reuse for agriculture to compare with UF membrane use as tertiary treatment or
CAS process. UF membrane can also apply to treat industrial wastewater as tertiary
treatment for reuse in agriculture.
70
Table 4.8 Comparison the effluent of CAS, A-MBR and UF processes with the standards
Parameter
pH
Conductivity
COD
BOD5
SS
Color
Total coliform
E.Coli
Zn
Cr
Ni
Cd
nd: not detected
(*): FAO guideline
(**): WHO guideline
Unit
mS/cm
mg/L
mg/L
mg/L
Pt-Co
MPN/100 mL
MPN/100 mL
mg/L
mg/L
mg/L
mg/L
Effluent of CAS
7.5±0.4
4.2±0.5
87±26
18±1.5
49±81.3
162±67
1.6x103 -1.7x104
1.7x102-1.4x103
0.28±0.25
0.96±1.1
nd
nd
Effluent of A-MBR
7.8±0.4
3.8±0.8
54±22
13±2.6
nd
112±42
7.8x100 – 1.3x102
<1.8
0.25±0.17
0.15±0.05
nd
nd
71
Effluent of UF
7.5±0.3
4.01±0.58
68±23
15±1.4
nd
132±32
2.0x100 – 2.2x101
<1.8
0.27±0.29
0.6±0.5
nd
nd
QCVN 24/2009
5.5-9
0.7 – 3 (*)
100
50
100
70
5.0x103
1.0x103 (**)
3
1
0.5
0.01
4.8 TMP of membrane systems
TMP of A-MBR
A-MBR was operated with flux 30 L/m2.h (OLR1). TMP of A-MBR increased from 48.7
to 55.6 kPa during operating period. TMP was steady at 53 kPa from day 10 to day 37 and
slightly increase to 55.7 kPa on day 45 and steady at this value. Then, chemical cleaning
(CIP) was conducted on day 48. Compare to Flux 30 L/m2.h, TMP of flux 45 L/m3.h
increased rapidly. TMP slightly increased from 48.7 to 50.3 kPa on third day. It steady at
this value around day 9th and increased sharply to 55.3 kPa on day 16th and increased to
58.16 kPa on twenty three. Chemical cleaning was conducted after thirty days. TMP as
flux 45 L/m3.h (OLR2) was faster increasing than TMP of flux 30 L/m2.h. It could be due
to higher flux and MLSS of OLR2 than OLR1. MLSS of OLR1 was 6,996 mg/L to
compare with 7,554 mg/L of OLR2. Figure 4.26 showed variation of TMP of AMBR
during operating period.
Figure 4.24 (a): Variation TMP of A-MBR at Flux 30 L/m2.h
L/m2.h
Figure 4.24(b): Variation TMP of A-MBR at Flux 45
TMP of UF
Initial day TMP of UF was steady at 9.8 kPa. It sharply reached to 122.6 kPa on day 16th,
December, 2010. Membrane was clogged severely and it has taken pretty long time to
recover the membrane due to severe fouling. On day 3, January, 2011, TMP reached to
73.5 kPa and membrane clogging again. Other days, TMP was also changed unsteady.
Detail data was present on table K3, appendix K. The main cause of membrane clogging
was sludge from effluent of CAS process which got inside the channels of membrane and
got clog. Inserting sand filtration before UF membrane could solve this problem. It could
avoided membrane clogging phenomenon as before. During operating period with
inserting sand filtration, TMP of UF membrane was steadier. This result pointed that UF
operation could affect severely due to unexpected floating sludge from CAS process. For
safety, insertion of sand or other type of filter has to insert in these types of WWTP where
the risk of poor effect from secondary settling tank is high. The serious membrane
clogging was a cause of very high SS concentration at CAS effluent. Figure 4.25 showed
variation of UF membrane TMP during operating period.
72
SS: 350 mg/L
Rapid increasing due to floating sludge
Sand filter pre-treatment
SS: 268 mg/L
SS: 186 mg/L
SS: 159 mg/L
SS: 346 mg/L
Figure 4.25 Variation TMP of UF membrane during the operating period
4.9 Effect quality vs reuse standard
Table 4.9 show the removal efficiency of three organic loading rate (OLR) of A-MBR
process to compare with CAS process. Conductivity removal efficiency of OLR2 and
OLR3 was higher than OLR1, 23, 19 and 13%, respectively whereas conductivity removal
efficiency of CAS process was 11%. It could be the cause of higher MLSS in aeration
tank of OLR2 and OLR3 than OLR1 that can lead to increasing removal heavy metals by
precipitate classification and membrane separation. COD removal efficiency of OLR1,
OLR2 and OLR3 was 79, 90 and 86%, respectively whereas COD removal efficiency of
CAS process was 78%. BOD5 removal efficiency of three OLR was not much different
and little bit higher than CAS process (1-2%). It could be cause of low BOD5 influent
around 170 mg/L. Color removal efficiency of OLR1, OLR2 and OLR3 was 65, 81 and
72%, respectively whereas color removal efficiency of CAS process was 67%. This result
indicated that highest removal efficiency was OLR2 and lowest removal efficiency was
OLR1. It is ranged OLR2 (5.7 kg COD/m3.d), OLR3 (4.1 kg COD/m3.d) and OLR1 (1.8 kg
COD/m3.d).
With these unsteady observations, it is difficult to conclude a suitable optimum operating
conclusions. However, the A-MBR has performed far better than CAS process. It could
accommodate high loading rate and better quality effluent.
73
Table 4.9 Removal efficiency A-MBR at different three OLR
Parameter
Conductivity
COD
BOD5
SS
Color
Efficiency
removal of CAS
(%)
11.0
78.0
90.3
57.0
67.0
Efficiency
removal of OLR1
(%)
13.0
79.0
91.9
100
65.0
Efficiency
removal of OLR2
(%)
23.0
90.0
92.6
100
81.0
Efficiency
removal of OLR3
(%)
19.0
86.0
92.9
100
72.0
4.10 Operating problems and suggestion
Operational problems during treatment wastewater in Le Minh Xuan IP were investigated
in the study with A-MBR and UF membrane. The problem was unsteady operation of
CWWTP. Table 4.10 show the problems of operation, results and solutions to overcome
with problems.
Table 4.10 Operational problems solution/suggestion of A-MBR and UF pilot scale
system
Problem
Coarse materials come into
aeration tank of A-MBR
Observation
Not good for membrane.
May be damage
membrane and clogging
the feed pump that
reduces the power of feed
pump (effect on TMP
measurement)
Suggestion
Insert a sedimentation tank
and a screen (1 mm), before
aeration of A-MBR system,
to prevent coarse materials
come A-MBR membrane.
Opening feed pump and
clean it.
Too much of sludge from
secondary sedimentation
come to UF membrane in
some occultation
unexpectedly.
Membrane got clogging
Insert a sand filtration
before UF membrane, to
prevent sludge directly
come into UF membrane.
COD influent was not
steady at three OLR of AMBR process. OLR2 was
higher than OLR3.
Proper analyser of long term
It was not like initial
calculation of loading rate. data of WWTP regular
before pilot scale start.
Could not measure TMP of Increasing TMP rapidly.
A-MBR at OLR3 due to
membrane clogging
Increasing regular chemical
membrane cleaning. One
time per week.
High temperature in
aeration tank of A-MBR
system and high energy
consumption result in high
Using proper feed pump. It
could use high pressure
pump with lower power that
can keep the same flow rate,
Average temperature was
40 oC. Energy
consumption was higher
10 times to compare with
74
power of feed pump.
Norit’s information.
but not more effect on high
temperature and energy
consumption.
Increasing filtration time of
A-MBR (20 min to
compare with 10 min of
Norit information) due to
using higher capacity of
backwash pump (18 L/min
to compare with 8 L/min
of Norit Information).
Could not reduce flow rate
of backwash pump due to
air coming to membrane in
backwash step.
Increasing treated water
from collected tank return
back to aeration tank of
A-MBR.
Using proper backwash
pump. Change backwash
pump with lower capacity.
Stop supply feed water
from primary
sedimentation tank to
aeration tank of A-MBR,
especially in evening, due
to no wastewater discharge
from factories.
Increasing concentration
of sludge in aeration that
can lead to membrane
fouling due to sludge very
concentrate.
Connect electric role with
feed pump. Turn off feed
pump, suction pump and
backwash pump when
reducing water level in
aeration tank of A-MBR.
To design the membrane system for wastewater treatment as Le Minh Xuan IP should
think careful about the history profiles of IP, the variation of influent and effluent quality.
It should be do some tests to compare with that, and then thinking over the problems that
will come and find out the solution to prevent them by experiences.
In pilot scale study at LMX IP, high variation of COD influent concentration was effects
on initial purpose of study on three OLRs of A-MBR. At OLR2, feed COD was double
higher than OLR1 and OLR3 that lead to OLR2 higher than OLR3. It is different as initial
purpose. The unsteady operation or not good performance of secondary sedimentation of
LMX IP was effect on UF membrane operation due to clogging. That is main cause of
very different TMP of UF membrane.
To over come with this limitation, SS effluent of CAS process should be estimated more
by increasing the frequency of sample taking such as three time per day and one time per
two day fro further study or incorporation of inline turbidity measurement with TMP
measurement can be done.
4.11 Cost of membrane
Cost of membrane technology includes capital cost, O&M cost and life-cycle cost.
•
Capital cost included direct cost, indirect cost and land cost.
75
Direct costs includes equipment for all unit processes, mobilization, site preparation, site
electrical, yard piping, instrumentation and control, laboratory and administration
buildings.
Indirect costs includes legal fees, engineering design, inspection, contingency and
miscellaneous
•
O&M cost includes labour, materials, energy and chemicals
Case study of comparison of membrane options for water reuse and reclamation by Pierre
Côté, Michel Masini and Diana Mourato. (2004).
Comparison capital cost of three systems, they are MBR, CAS and CAS+TF (tertiary
filtration). MBR plants are less expensive than CAS and CAS+TF plants due to saving
land cost for secondary clarifiers and reducing the sixe of aeration tank. The capital cost
of CAS+TF is highest due to adding more membrane cost and without eliminating
anything.
Comparison O&M cost of MBR, CAS and CAS+TF.
O&M cost of MBR and CAS+TF is higher than CAS about 20 – 30%. O&M cost of MBR
is lightly higher than CAS+TF due to requirement of higher scouring aeration rate and the
membrane replacement cost.
Total life cost
Total life cost of CAS plants is lowest. Following is MBR and CAS+TF plants. Total life
cost of MBR and CAS+TF is higher than CAS about 5 – 20%. It is increasing with
increasing size plant.
76
Chapter 5
Conclusions and Recommendations
This study focused on the identification of potential industrial wastewater reuse for
agriculture in peri-urban areas of HCMC. Data collection such as impact of industrial
wastewater on water resources, farmer health and agricultural activities in HCMC is
combined with removal efficiency of A-MBR and UF systems in treating industrial
wastewater agricultural reuse purpose. A-MBR system was operated with three different
organic loading rates including 1.8 kg COD/m3.d, 4.1 kg COD/m3.d and 5.7 kg COD/m3.d
in order to optimize its operating conditions.
5.1
Conclusions
Following conclusions indicated the high potential of industrial wastewater reuse for
agriculture in HCMC.
•
Availability of water resources is decreasing due to water pollution, over
exploitation of water supply from water resources and salt intrusion that lead to
serious problems on agriculture in HCMC.
•
The huge amount of untreated or insufficiently treated wastewater, especially
industrial wastewater, directly discharges into water resources that is over the selfpurification capacity of water sources. As a result, water sources are polluted that
can not use for any purposes. It also has many negative effects on environment,
human health and agricultural activities. Therefore, treated industrial wastewater
for reuse can play a significant role to prevent pollution of water resources and
also deal with water scarcity at a moment period in HCMC.
Following conclusions were made on the performance of A-MBR and UF to compare
with conventional activated sludge and standard for wastewater reuse.
The experimental results obtained from pilot-scale study at Le Minh Xuan IP indicated
that membrane processes are suitable for industrial wastewater treatment to reuse for
agriculture.
•
The pH effluents of A-MBR and UF were around 7.83±0.37 and 7.5±0.32,
respectively. They met standard for wastewater reuse in agriculture or discharge
into downstream. It was not much different to compare with pH effluent of CAS
process (7.5±0.41).
•
COD removal efficiency of A-MBR was 85.33% and COD removal efficiency of
CAS+UF process was 84.05% whereas COD removal efficiency of CAS process
was 78.56%. Two membrane systems always met the standard for industrial
wastewater reuse for agriculture to compare with CAS process in term of COD
because in some day COD effluent of CAS was over the standard.
•
BOD5 effluent of three processes always met standard for industrial wastewater
discharge into water bodies or wastewater reuse. It may be a cause of low feed
BOD5 of wastewater in LMX IP (178 mg/L).
77
•
Permeate of A-MBR and UF membrane was nearly free suspended solids that
would be suitable for reuse due to high quality treated wastewater. Effluent SS of
CAS process was upper standard in some days. Therefore, it is careful in term of
reuse.
•
Effluent conductivity and color of CAS, A-MBR and UF processes did not meet
standard for industrial wastewater discharge or reuse. Conductivity removal
efficiency of three processes was not high. Conductivity removal of CAS, A-MBR
and CAS+UF processes was 10.9%, 18.8% and 14.9%, respectively. Color
removal of CAS, A-MBR processes and CAS+UF processes was 67.3%, 73.7%
and 72.6%, respectively.
•
Heavy metals’ effluent of CAS, A-MBR and UF processes met standard. Cd and
Cr were not detected at effluents. Effluent Zn of CAS, A-MBR and CAS+UF was
0.07 – 0.55, 0.11 – 0.43 and 0.03 – 0.59 mg/L, respectively. Effluent Ni of CAS,
A-MBR and CAS+UF processes was 0.18 – 2.22, 0.09 – 0.19 and 0.16 – 0.46
mg/L, respectively.
•
Total coliform and E.coli effluent of A-MBR and UF processes alway met
standard for industrial wastewater discharge whereas, some times, effluent of CAS
did not meet standard. Therefore, CAS effluent has to do disinfection step before
discharge into water bodies.
•
TMP at flux 45 L/m2.h (OLR2) increased faster than TMP at flux 30 L/m2.h
(OLR1).
•
COD removal efficiency of A-MBR process at OLR 5.7 kg COD/m3.d was higher
than OLR 4.1 and 1.8 kg COD/m3.d. COD removal efficiency of OLR 1.8, 4.1 and
5.7 kg COD/m3.d was 79%, 86% and 90%, respectively. Similarly, color removal
efficiency of A-MBR process at OLR 5.7 kg COD/m3.d was also higher than OLR
4.1 and 1.8 kg COD/m3.d. Color removal efficiency of OLR 1.8, 4.1 and 5.7 kg
COD/m3.d was 65%, 72% and 81%, respectively.
It can apply membrane technology to treat industrial wastewater for agricultural reuse in
HCMC. UF membrane system can apply to treat wastewater after exiting CAS process
and A-MBR can apply for new one due to higher treated performance.
5.2
Recommendations for further studies
Experimental further study on wastewater impacts on crop yield and quality as well as
relationship between wastewater and human health have to carry out to find out scientific
evidences. It will strongly support for the results of this research.
Further study on removal efficiency of membrane technology for treated different kinds of
industrial wastewater will be carried out in HCMC to compare with this result. It can
clearly reveal potential of membrane technology, applying treated industrial wastewater
reuse for agriculture in HCMC. Further study on economic factors such as investment cost
and O&M cost of membrane technology to compare with traditional technology also have
to be done for suitable with HCMC condition. Land cost in HCMC is very high.
78
Therefore, saving land space of membrane technology is very attracted to compare with
tradition technology.
Effluent color or conductivity of LMC IP did not meet standard for industrial wastewater
discharge or ruse. Therefore, it should be considered for further study such as pretreatment or post treatment to meet standard for wastewater reuse.
Over load capacity of CWWTP of LMX IP is the main cause of unsteady operation of
WWTP system. The pilot scale for further study on membrane technology should be
considered because it strongly affects removal efficiency of CAS process due to effects on
HRT and sludge sedimentation.
Feed COD of LMX IP was changing very much. It was low in rain season and high on
December to January. Further study can operate the same organic loading rate to compare
with CAS process base on changing feed COD.
Low feed COD in rain season of LMX IP can lead to reducing MLSS in aeration tank at
low OLR (1.8 kg COD/m3.d). Therefore, it can be considered in further studies.
79
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assessment of industrial estates at HCMC. University of Technology, Vietnam
National University - Ho Chi Minh City. Magazine of science and technology
development 12 (8).
Triqua. (2002). Operation Manual Cross Flow MBR Plant. Wageningen.
Tutuka, Q.W.C., Keegan, A., & Jin, B. (2009). Fate of pathogenic microorganisms and
indicators in secondary activated sludge wastewater treatment plants. Journal of
Environmental Management, 90, 1442–1447.
USEPA. (2004). Guideline for water reuse. United State Environmental Protection
Agency.
Retrived
August
2010,
from
website:
hppt://www.epa.gov/nrmrl/pubs/625r04108/625r04108.pdf
Vigneswaran, S., & Sundaravadivel, M. (2004). Recycle and reuse of domestic
wastewater. Faculty of Engineering, University of Technology, Sydney, Australia,
and Graduate School of the Environment, Macquarie University, Sydney, Australia.
Visvanathan, C., and Asano, T. The potential for industrial wastewater reuse.
Environmental Engineering Program. Asian Institute of Technology, and
Department of Civil and Environmental Engineering, University of California at
Davis.
Retrieved
August,
2010,
from
website:
hppt://www.faculty.ait.ac.th/visu/.../15/fiinaltext-dinesh.pdf.
Visvanathan, C., Chongrak, P., & Thammarat, K. (2005). Water reuse potentials in
thailand. Fourth Aquatech Asia 2005 Conference on Sustainable Water Resource
Management and Sustainable Wastewater Technology. BITEC, Bangkok, Thailand.
Retrieved
August,
2010,
from
website:
hppt://www.faculty.ait.ac.th/visu/Data/Publications/.../WW-Reuse.pdf.
VIWASE. (2001). Master Plan for Water Supply System of HCMC and Development
Trend to the year 2030. HCMC: Vietnam Water Supply and Environment
Company.
Water Enviroment Federation. (2006). Membrane systems for wastewater treatment. New
York: WEF Press McGraw-Hill.
Wisniewski, C. (2007). Membrane bioreactor for water reuse. Desalination, 203, 15–19.
Zanetti, F., Luca, G.D., & Sacchetti, R. (2010). Performance of a full-scale membrane
bioreactor system in treating municipal wastewater for reuse purposes. Bioresource
Technology, 101 (10), 3768-3771.
85
APPENDIX A
Vietnamese industrial wastewater – Discharge standard
(QCVN 24/2009/MTNMT)
Table A1: C Value of pollution parameters in industrial wastewater
No
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
Parameter
Temperature
pH
Odour
Colour (Co-Pt at pH = 7)
BOD5 (20oC)
COD
Suspended solids
Arsenic
Mercury
Lead
Cadimium
Chromium (VI)
Chromium (III)
Cooper
Zinc
Nickel
Manganese
Iron
Tin
Cyanide
Phenol
Mineral Oil and fat
Animal-vegetable oil and fat
Chlroine residual
PCBs
Pesticide: organic phosphrous
Pesticide: organic chlorine
Sunfide
Fluoride
Chloride
Ammonia (as N)
Total Nitrogen
Total Phosphorous
Coliform
Gross α activity
Gross β activity
Unit
o
C
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
MPN/100mL
Bq/L
Bq/L
86
C Value
A
B
40
40
6-9
5.5-9
comfortable
comfortable
20
70
30
50
50
100
50
100
0.05
0.1
0.005
0.01
0.1
0.5
0.005
0.01
0.05
0.1
0.2
1
2
2
3
3
0.2
0.5
0.5
1
1
5
0.2
1
0.07
0.1
0.1
0.5
5
5
10
20
1
2
0.003
0.01
0.3
1
0.1
0.1
0.2
0.5
5
10
500
600
5
10
15
30
4
6
3
3x10
5x103
0.1
0.1
1.0
1.0
TCVN 6773:2000 Water quality – Water quality guidelines for irrigation
2. Levels of irrigation water quality
Table A5 - Water quality irrigation
Parameter (mg/L)
Value
>1000
>1
>1
<2
5.5 8.5
>350
>0.001
0.005-0.01
0.05-0.1
0.1
TSS
Salinity
Bo
DO
pH
Cl
Hg
Cd
As
Pb
87
APPENDIX B
USEPA Guideline for Water Reuse
Table B1: USEPA Guidelines for Water Reuse
Type of Reuse
Treatment
Required
AGRICULTURAL Secondary
Food crops
Disinfection
commercially
processed
Reclaimed
Water Quality
pH = 6-9
BOD ≤ 30 mg/l
SS = 30 mg/l
FC ≤ 200/100
ml
Cl2 residual = 1
mg/l min.
Recommend
Monitoring
pH weekly
BOD weekly
SS daily
FC daily
Cl2 residual
continuous
PASTURAGE
Secondary
Pasture for milking Disinfection
animals
Pasture for
livestock
pH = 6-9
BOD ≤ 30 mg/l
SS ≤ 30 mg/l
FC ≤ 200/100
ml
Cl2 residual = 1
mg/L min.
pH weekly
BOD weekly
SS daily
FC daily
Cl2 residual
continuous
FORESTATION
pH = 6-9
BOD ≤ 30 mg/l
SS ≤ 30 mg/l
FC ≤ 200/100
ml
Cl2 residual = 1
mg/L min.
pH weekly
BOD weekly
SS daily
FC daily
Cl2 residual
continuous
pH = 6-9
BOD ≤ 30 mg/l
Turbidity ≤ 1
NTU
FC = 0/100 ml
Cl2 residual = 1
mg/L min.
pH weekly
BOD weekly
Turbidity daily
FC daily
Cl2 residual
continuous
Orchards and
Vinerds
Secondary
Disinfection
AGRICULTURAL Secondary
Food crops not
Filtration
commercially
Disinfection
processed
Setback
Distances
300 ft from
potable water
supply wells
100 ft from
areas
accessible to
public
300 ft from
potable water
supply wells
100 ft from
areas
accessible to
public
300 ft from
potable water
supply wells
100 ft from
areas
accessible to
the public
50 ft from
potable water
supply wells
Source: USEPA, Process Design Manual: Guidelines for Water Reuse, EPA/625/R-04/108
September 2004. Washington, DC.
88
Appendix C
FAO guideline for salt content of irrigation water
Table C1: Guidelines for interpretation of water quality for irrigation
Potential irrigation problem
Salinity
ECw1
TDS
Infiltration
SAR2 = 0 - 3 and ECw
3 -6
6-12
12-20
20-40
Units
Degree of restriction on use
None
Slight to moderate
Severe
dS/m
mg/L
< 0.7
< 450
0.7 - 3.0
450 - 2000
> 3.0
> 2000
> 0.7
> 1.2
> 1.9
> 2.9
> 5.0
0.7 - 0.2
1.2 - 0.3
1.9 - 0.5
2.9 - 1.3
5.0 - 2.9
< 0.2
< 0.3
< 0.5
< 1.3
< 2.9
Note: ECw means electrical conductivity in deci-Siemens per metre at 25°C
SAR means sodium adsorption ratio
FAO, Crop water need
Table C2: Indicative values of crop water needs
Crop water need
(mm/total growing period)
800-1600
1,200-2,200
450-650
300-500
350-500
900-1,200
700-1,300
500-800
400-600
350-550
500-700
350-500
600-900
500-700
450-700
450-650
450-700
550-750
1,500-2,500
600-1,000
400-800
Crop
Alfalfa
Banana
Barley/Oats/Wheat
Bean
Cabbage
Citrus
Cotton
Maize
Melon
Onion
Peanut
Pea
Pepper
Potato
Rice (paddy)
Sorghum/Millet
Soybean
Sugar beet
Sugarcane
Sunflower
Tomato
89
APPENDIX D
Questionnaire Survey and Summary of statistic of the results
Water use for Agriculture Questionnaire
1/ Location: ............................................................................................................................
2/ Area of agricultural Land:..................................................................................................
3/ Kind of vegetables farmed: ................................................................................................
................................................................................................................................................
4/ Income: ..............................................................................................................................
5/ Status of water use for agriculture: ....................................................................................
................................................................................................................................................
................................................................................................................................................
6/ Demand of water use for watering:....................................................................................
................................................................................................................................................
7/ Quantity and quality of water resources supplying for agriculture: ..................................
................................................................................................................................................
8/ Sources and causes of water pollution: ..............................................................................
................................................................................................................................................
9/ Effects of water pollution on yield crops: ..........................................................................
................................................................................................................................................
10/ Effects of water pollution on public health:.....................................................................
................................................................................................................................................
................................................................................................................................................
11/ Attitudes on wastewater reuse including farmers and local authorities; .........................
................................................................................................................................................
................................................................................................................................................
................................................................................................................................................
12/ Awareness of farmers about wastewater reuse for vegetable: .........................................
................................................................................................................................................
................................................................................................................................................
13/ Safety precautions of farmers such as wear comforter or cover their hands, etc. ...........
................................................................................................................................................
................................................................................................................................................
14/ Comments: .......................................................................................................................
................................................................................................................................................
................................................................................................................................................
................................................................................................................................................
Day….. Month….. Year 2010
The questionnaire is just used for thesis data collection
Thank you for Your Cooperation
90
Tình Trạng Sử Dụng Nước Trong Nông Nghiệp Trên Địa Bàn TPHCM
1/ Địa điểm : .............................................................................................................................
2/ Diện tích đất sử dụng: .........................................................................................................
3/ Loại cây trồng: ......................................................................................................................
.................................................................................................................................................
4/ Thu nhập: .............................................................................................................................
.................................................................................................................................................
5/ Tình trạng sử dụng nước trong nông nghiệp: ................................................................................
.................................................................................................................................................
.................................................................................................................................................
6/ Nhu cầu sử dụng nước cho tưới tiêu: ..................................................................................
.................................................................................................................................................
7/ Số lượng và Chất lượng và nguồn nước mặt:.........................................................................
.................................................................................................................................................
8/ Nguồn và các nguyên nhân gây ra ô nhiễm nguồn nước: ..............................................................
.................................................................................................................................................
.................................................................................................................................................
9/ Ảnh hưởnng của việc sử dụng nước thải tới chất lượng cây trồng và sản phẩm: ................
.................................................................................................................................................
10/ Ảnh hưởng của nước thải tới sức khỏe: .............................................................................
.................................................................................................................................................
.................................................................................................................................................
11/ Nhận thức về tái sử dụng nước thải của cả nông dân và chính quyền địa phương;
12/ Nâng cao nhận thức của nông dân về tái sử dụng nước thải cho nông nghiệp: ............................................
............................................................................................................................................................................
13/ An toàn của nông dân biện pháp phòng ngừa như đeo khẩu trang hoặc bao che tay
.................................................................................................................................................
.................................................................................................................................................
12/ Ý kiến:...............................................................................................................................
.................................................................................................................................................
.................................................................................................................................................
.................................................................................................................................................
.................................................................................................................................................
Ngày….. tháng….. năm 2010
Bảng câu hỏi chỉ được sử dụng để thu thập dữ liệu luận án.
Cảm ơn bạn đã hợp tác của bạn.
91
Table D1: Summary of industrial wastewater effects on water resource, agriculture and human health from data collection form
questionnaire survey
Location
(District)
Agricultural area
of District
(ha)
Average Status of water
use for
Yield
agriculture
(ton/ha)
Quality of
irrigations
Sources and
causes of
water
pollution
Effects of
water
pollution on
yield crops
Effects of
water
pollution on
public health
Wastewater
reuse
awareness
of farmers
Safety
precautions
of farmers
Low yield,
yellow leaves
of rice
Lack of water
Lack of water
for
agriculture
Good for
WMG
-
Itches, scabies
and no idea
other diseases
treated
Industrial
wastewater
-
Itches, scabies
and no idea
other diseases
treated
Industrial
wastewater
Wear
protection
cloths.
-
-
-
Binh Chanh
Le Minh Xuan
Ward
Rice: 25.8
3.5
C canal,
rain water
Pollution
Le Minh Xuan
IP
Tan Tao Ward
Rice: 13.5
Morning glory: 6
Duckweed: 2
3.5
Canal 1
C Canal
Xam Canal
Rain water
Pollution
Tan Tao IP
Tan Nhut
Ward
Rice: 12
4.5
Xang River,
rain water
Still good
-
-
Ba Hom Canal
pollution
Tan Tao IP
Good for
WMG
Itches and
scabies
and no idea
other diseases
treated
Industrial
wastewater
-
4.5
Rain water
pollution
Vinh Loc IP
-
Ground water
Tran Quang Co
Canal
pollution
-
Itches and
scabies
and no idea
other diseases
Itches and
scabies
and no idea
other diseases
treated
Industrial
wastewater
5
Lack of
water, 1 crop
per year (rain
water)
Lack of water
treated
Industrial
wastewater
-
Binh Tan
Binh Tri Dong
Ward
Water morning
glory (WMG): 5
Hoc Mon
Xuan Thoi
Thuong Ward
Rice: 5
Dong Thanh
Ward
Vegetable: 25
92
Table D1: Summary of industrial wastewater effects on water resource, agriculture and human health from data collection form
questionnaire survey (cont)
Location
(District)
Agricultural
area of
District
Average
Yield
Status of water
use for
agriculture
Quality of
irrigations
Sources and
causes of
water
pollution
Effects of
water
pollution on
yield crops
Effects of
water
pollution on
public health
Wastewater
reuse
awareness of
farmers
Safety
precautions
of farmers
Heavy
Pollution
Cu Chi
NorthWest IP
Reduce
vegetable
yield
Itches,
scabies
and no idea
other diseases
-
treated
Industrial
wastewater
-
-
-
Itches,
not use for
scabies
safe vegetable,
and no idea
use for water
other diseases
mimosa,
morning glory
Using for
Itches,
WMG,
scabies
vegetable,
and no idea
water mimosa other diseases
treated
Industrial
wastewater
-
treated
Industrial
wastewater
Wear
protection
cloths.
(ton/ha)
(ha)
Cu Chi
Binh My Ward Vegetable: 15
3-4
An Ha Ward
Vegetable: 6
Rice: 13
4-5
4.5
An Ha Canal,
Dong Canal and
rain water
Tan Thoi Hiep
Ward
Vegateble: 19
5
Ground water
Tran Quang Co
Canal
Heavy
pollution
Thoi An Ward
Vegetable: 7
3.5 - 4
Tran Quang Co
Canal,
Dua canal
Heavy
pollution
Clean in rain
Tan Quy IP,
season,
Tan Phu Trung
polluted in
IP
dry season
-
District 12
Tan Thoi Hiep
IP,
Quang Trung
industrial
cluster
Tan Thoi Hiep
IP,
Quang Trung
industrial
cluster
93
Table D2: The effect of wastewater on agricultural activities based on farmers’
perception
Issue
Cause of water pollution from industries
Pollution of irrigation systems
Polluted water of canals is a cause of lack water for
agriculture
Effects of polluted water on crop yields
• Wastewater good for rice
• Wastewater good for vegetable
• Wastewater good for water morning glory
Impact of polluted water on crop quality
Negative effects of wastewater on human health
Treated industrial wastewater before discharge into
water bodies
Wearing protected cloth
•
Yes
(%)
100
80
90
No
(%)
0
20
10
70
0
30
100
100
100
100
30
100
70
0
0
0
0
20
80
Farmers’ interview was conducted at 10 different wards in 5 districts. In average,
5 farmers were interviewed at one place. Total interviewed farmers were 50
people.
94
APPENDIX E
Le Minh Xuan Industrial Park
CWWTP
Figure E1: Aerial view of Le Minh Xuan IP
Figure E2: Factories in Le Minh Xuan industrial Park
95
Textile, Dying,
Washing and
Clothing
Others
Pesticide
Mechanism
Plastic Production
Figure E3: Percentage of water consumption of different production in LMX IP
6000
(m3/day)
5000
4000
3000
2000
1000
Tet’s holiday
0
January
February
March
Figure E4: Variation of actual flow rate of LMX IP in 2011 (LMX IP)
96
Figure E5: Central WWTP of Le Minh Xuan Industrial Park
Equalization tank
Screen
Collecting sludge tank
Figure E6.a, E6.b: Two parallel systems of WWTP in CWWTP of Le Minh Xuan
industrial park
97
Figure E7: Schematic diagram of CWWTP of LMX IP
Table E1: Volume of tanks in CWWTP in LMX IP
Volume (m3)
Equalization Tank
pH Adjustment Tank
Coagulation Tank
Flocculation Tank
Primary Sedimentation Tank
Neutralization Tank
Aeration Tank
Secondary Sedimentation Tank
Chlorine Tank
Sludge Stabilization Tank
Soure: LMX IP
Value
850
14
14
35
107
14
2,000
151
55
256
98
Table E2: Operating condition of CWWTP of LMX IP
Parameter
Flow rate
Feed COD
F/M
MLSS
HRT
SRT
DO
pH
Temp
OLR
Source: LMX IP
Unit
m3/d
mg/L
day-1
mg/L
h
day
mg/L
o
C
kg COD/m3.d
Value
3,000
500
0.136
4,500 – 6,500
16
22.5
2.5 – 4.5
7.0 – 8.0
28 - 38
0.75
Secondary
Sedimentation Tank
Aeration Tank
Primary
Sedimentation Tank
Figure E8: A photo of general WWTP system of LMX IP
99
Figure E9: Equalization tank
Figure E11: Primary sedimentation tank
tank
Figure E10: Screen
Figure E12: Bioreactor Tank
Figure E14: Collect sludge tank from Primary sedimentation tank
Figure E13: Secondary sedimentation
Figure E15: Collected sludge from secondary sedimentation tank
100
Chlorine disinfection
Figure E16: Chorine disinfection
Figure E17: Effluent after disinfection process
Figure E18 and E19: Sludge Thickening
101
APPENDIX F
Table F1: Existing and predicted water intake capacity of water resources for
provinces of Sai Gon and Dong Nai river catchment basin
Raw water
2000
2010
2015
3
3
3
resources
m /day
%
m /day
%
m /day
Dong Nai
900,000 47.2 1,562,000 61.5 2,277,000
River
Tri An
0
0
0
Reservoir
Sai Gon River
320,000 16.7 320,000 12.6 500,000
Dong canal
0
220,000 8.7
0
Dau Tieng
0
0
825,000
Reservoir
GW exploited
92,000
4.8 137,000 5.4 177,000
by WSC
GW exploited
600,000 31.3 300,000 11.8 63,000
by community
(*)
Total
1,912,000 100 2,539,000 100 3,842,000
Source: VIWASE, 2001
Note: (*) Community includes household, services and industries.
GW: ground water, WSC: Water Saigon Company
2025
%
m /day
%
59.2 1,610,000 33.9
3
0
1,500,000 31.6
13
500,000 10.5
0
0
21.6 1,100,000 23.2
4.6
0
0
1.6
40,000
0.8
100
4,750,000 100
Table F2: Water quality of Dong Canal from 2007 to 2009
Parameters
Unit
2007
pH
6.29
TSS
mg/L
49.7
Conductivity
mS/cm
4.19
Turbidity
NTU
9.42
Total N
mg/L
0.66
Total P
mg/L
0.16
COD
mg/L
4.1
BOD5
mg/L
2.1
Pb
mg/L
0.002
Cd
mg/L
0.04
Hg
mg/L
<0.001
Oil
mg/L
0.03
Total coliform MPN/100 mL
5.9x104
E.coli
MPN/100 mL
40
Source: HEPA, 2008, 2009 and 2010.
102
2008
5.91
53.5
3.65
7.36
0.5
0.09
4.0
2.8
0.002
0.001
<0.001
0.02
2.6x104
317
2009
6.3
4.3
3.1
<0.001
0.02
2.3x104
-
QCVN 08:2008
6 – 8.5
<20
0.1
0.1
<10
<4
0.02
0.005
0.001
0.01
<2.5x103
20
Table F3: Existing and predicted water consumption demands in HCMC
Sector
1995
(m /day) %
383,558 85
3
Domestic use
Industrial
50,413
zones
Industrial
19,624
cluster
Services
Total
453,595
Source: VIWASE, 2001
2005
(m /day) %
780,000
66
3
By 2010
(m /day) %
1,050,000 65
3
By 2015
(m /day)
%
1,178,868
66
3
11
140,000
12
210,000
13
314,375
17
4
61,000
5
80,000
5
100,745
6
205,000
17
270,000
17
205,598
100 1,186,000 100 1,610,000 100 1,799,586
11
100
Table F4: Fresh water reserve potential of aquifers in HCMC
The component recharge
Recharge from rainwater
Recharge from Dong canal
Recharge from Sai Gon River
Recharge from Northern and
Western boundaries of HCMC
Static gravity flow
Static elastic flow
Total
Source: Nga, 2005
Pleistocen
aquifer
(m3/day)
309,530
156,750
67,500
22,540
233,480
6,000
796,000
103
Upper Pliocene Lower Pliocene
aquifer
aquifer
3
(m /day)
(m3/day)
181,170
94,030
715,320
55,770
952,000
630,420
28,550
753,000
Table F5: Monitoring results of effluent quality at disposal outfalls of IZs in 2007 (HEPA, 2007)
No
1
2
3
4
5
6
7
1
1a
2
2a
3
4
4a
5
6
IZ
Position
With CWWTP:
Binh Chieu
Outfall(1)
Cat Lai
Outfall
Hiep Phuoc
Outfall
Tan Phu Trung(2)
Outfall
Tan Thoi Hiep
Outfall
Tay Bac Cu Chi (2)
Outfall
Vinh Loc
Outfall
Without CWWTP:
Le Minh Xuan
Effluent(3)
Le Minh Xuan
Outfall
Linh Trung 1
Effluent
Linh Trung 2
Outfall
Linh Trung 2
Effluent
Tan Binh
Outfall
Tan Binh
Effluent
Tan Tao
Outfall
Tan Thuan
Outfall
TCVN 5945-2005 Type B
Min
pH (mg/L)
Average
6.22
5.77
5.83
3.95
6.21
6.62
6.42
5.13
5.5
6.45
6.1
6.27
2.91
6.65
6.61
6.2
TSS (mg/L)
Average Max
Min
COD(mg/L)
Average Max
Min
BOD5(mg/L)
Average Max
Min
Oil (mg/L)
Average
Max
Max
Min
6.68
6.13
6.72
5.7
6.75
6.96
6.94
7.96
6.39
7.09
6.8
7.4
8.13
170
49
52
43
66
45
56
362
218
96
91
134
65
103
624
492
294
176
312
79
231
213
151
5.3
5
247
7
11
741
308
120
39
402
27
159
1514
724
610
97
672
61
423
72.4
67.0
0.5
1.2
81.0
3.0
2.3
271
141
73
11
164
14
61
607
241
574
36
237
30
167
4.2
0.4
1.3
0.1
1.3
0.1
1.1
8.00
4.95
5.74
1.21
10.32
1.50
4.78
13.2
12
36.4
3.2
33.8
2.6
11.2
6.28
6.53
6.72
6.57
6.7
6.58
7.09
6.98
7.02
5.5 -9.0
7.4
12.08
6.9
7.06
7.1
7.45
7.68
7.45
11.35
49
57
32
42
24
31
32
58
44
97
384
50
66
41
91
47
78
117
100
143
5188
69
151
51
764
69
116
433
13
8
11.2
17
5.3
5
6.09
78
8.5
82
366
31
52
21
170
16
148
116
100
197
3936
74
218
52
1194
37
249
422
2.4
4.9
4.1
9.0
1.0
4.6
1.1
55.0
2.3
34
108
9
24
9
60
8
65
49
50
80
1009
21
74
24
348
26
86
250
1.2
0.9
0.7
0.6
0.7
0.1
1.5
1.3
0.6
2.53
3.15
2.20
1.80
1.35
2.91
2.15
4.37
2.52
1.0
4.1
16.9
3.6
3.2
2.8
13.6
3.5
16.2
22.6
Note:
– Outfall of drainage system of IZ to the receiving water
– IP has not completed to build the wastewater drainage system. Therefore, the water from these outfalls was mainly storm-water and small
volume of industrial wastewater from a few industries
– Effluent of the central wastewater treatment plants
104
Table F6: Water quality of receiving water bodies (HEPA, 2008)
Le Minh Xuan
Parameter
pH
SS
DO
COD
BOD5
Total N
Total P
N-ammonia
N-NO3
Total Coliform
As
Hg
Pb
Cd
Cr 6+
Cr 3+
Cu
Zn
Ni
Phenol
Unit
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
MPN/100m
L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
Canal 6
Canal 8
5.5-6.8
3-155
1.1-5.2
25-300
19-160
3.3-19
0.02-3.34
5.5-7.2
16-111
1.2-4.5
67-300
19-160
7-21.1
0.08-5.09
Tan Thuan
Tan Tao
6.8-7.6
48-152
22-76
8.2-25.3
0.4-2.8
Tac Roi Canal
7.1-7.2
31-80
3.1-3.8
1-16
2.0-3.0
0.11-1.8
0.45-0.5
8.9.103-24.104
0.001
<0.0005
<0.02
<0.001
<0.05
<0.05
0.003-0.005
0.014-0.02
<0.05
<0.005
Vinh loc
6.0-6.3
37-57
42-70
18-39
2.7-5.7
3.4-11
1.8-4.3
1,100-36,000
Tan Binh
Tham Luong
Canal
2.7-7.18
31-105
66-270
20-72
Binh Chieu
Suoi Cai –Tac
River
Tan Phu
Trung
0.1-7
1.8-5.2
0.5-400
3.1-19.7
TCVN
5942-2005,
level B
5.5-9
80
≥2
< 35
< 25
12x103-4x105
1
15
10,000
9x103 – 3x109
<0.0001
0.39-0.21
<0.05
Note: TCVN 5942:2005-level B is Vietnamese surface water quality standards for rivers/canals which their water is used for agriculture,
irrigation or navigation
105
0.1
0.001
0.1
0.02
0.05
1
1
2
1
0.02
Table F7: Industrial parks and export processing zones in HCMC
No
IZ
01
02
03
04
05
06
07
08
09
10
11
12
13
14
15
Binh Chieu – IP
Cat Lai – IP
Hiep Phuoc IP
Le Minh Xuan IP
Linh Trung I –EPZ
Linh Trung II –EPZ
Phong Phu IP
Sai Gon Hi-Tech IP
Tan Binh IP
Tan Tao IP
Tan Thoi Hiep IP
Tan Thuan EPZ
Tay Bac Cu Chi IP
Vinh Loc IP
Tan Phu Trung IP
Location
Binh Chieu Ward, Thu Duc Dist.
Cat Lai Ward, Dist. 2
Nha Be Dist
Binh Chanh Dist.
Linh Trung Ward, Thu Duc Dist.
Binh Chieu Ward, Thu Duc Dist.
Binh Chanh Dist.
Dist. 9
Ward 15, Tan Binh Dist.
Binh Chanh Dist
Hiep Thanh Ward, Dist. 12
Tan Thuan Dong Ward, Dist. 7
Highway 22, Cu Chi Dist.
Binh Chanh Dist
Cu Chi dist.
Factories in IP
20
25
29
156
139
128
25
117
42
88
49
Source: HEPZA, 2008 and Tuan , 2009
106
Year
started
1996
1997
1996
1997
1992
1997
2002
2003
1997
1996
1997
1991
1997
1997
2008
Area
(ha)
1st stage
27.3
127
664
100
62
61.7
163.3
804
133.5
442
215.4
300
215.7
207
200
Area (ha)
in 2020
27.3
852
2000
100
62
61.7
163.3
804
250
460
215.4
300
345
207
500
Table F8. Medium-scale Industrial clusters in HCMC
No.
Industrial clusters
1
Binh Dang
2
Long Son
3
Phu Huu
4
Hiep Thanh
5
Thoi An
6
Saigon car factory
7
North of Thu Duc
8
Along Hanoi highway
9
Hiep Binh Phuoc
10 Hai Thanh
11 Viet Tai
12 Pounchen shoes factory
13 An Ha
14 Nhat Thanh
15 Le Minh Xuan
16 Da Phuoc
17 Hung Long
18 Truong Phu
19 Xuan Thoi Thuong
20 Tan Thoi Nhi
21 Xuan Thoi Son
22 Nhi Xuan
23 Dong Thanh
24 Bau Dung
25 Pham Van Coi
26 Tan Quy
27 SAMCO car factory
28 Bau Tran
29 Muong Chuoi
(DONRE, 2007)
Area in 2006
(ha)
33
50
175
158
26
19
200
130
20
17
10
62
80
150
100
100
100
15
143
250
38
100
78
110
100
300
112
100
74
107
Predicted area
(ha)
17
92
45
50
26
19
160
130
20
17
10
56
80
150
130
126
100
30
158
120
38
150
75
122
300
100
100
100
74
Table F9: Predicted water demand for industrial parks in HCMC.
No.
01
02
03
04
05
06
07
08
09
10
11
12
13
14
Total
Water Demand
(m3/day)
Industrial Park
2010
2,000
1,800
30,000
68,300
12,000
7,500
6,000
8,220
7,300
10,000
1,500
30,000
35,000
21,120
241,000
Binh Chieu
Cat Lai
Hiep Phuoc
Hi-tech industrial zone
Le Minh Xuan
Linh Trung I
Linh Trung II
Phong Phu
Tan Binh
Tan Tao
Tan Thoi Hiep
Tan Thuan
Tay Bac Cu Chi
Vinh Loc
2020
2,000
1,800
160,000
68,300
15,000
7,500
6,000
8,220
7,300
12,000
1,500
30,000
35,000
21,120
376,000
Source: HEPZA, 2008
Table F10: Total organic carbon (TOC) concentration of ground water of some
places in HCMC
TOC
(mg/L)
Place
Dong Thanh (Cu Chi District)
Dong Hung Thuan (District 12)
Linh Trung (Thu Duc District)
Tan Tao (Binh Tan District)
Source: HEPZA, 2008
2004
80.9
18
10.7
2006
168
39
19
13
18
Table F11: Concentration of heavy metals of ground water in HCMC
Parameter
s
Zn
(µg/L)
Pb
(µg/L)
Cu
(µg/L)
Cd
(µg/L)
Time
2006 (Dry)
2006
(Rainy)
2006 (Dry)
2006
(Rainy)
2006 (Dry)
2006
(Rainy)
2005 (Dry)
2005
(Rainy)
2006 (Dry)
2006
(Rainy)
Binh
Hung
49.7
Pham
Van Cuoi
69.5
Monitoring well
Tan Chanh
Phu
Hiep
Tho
16.6
15.9
54.2
6.9
12.1
2.1
1.5
2.1
52.1
7.3
5.0
59.3
0.4
11.0
3.4
1.2
1.7
3.0
Thu Duc
62.7
0.9
1.5
3.5
Tan Son
Nhat
1.5
8.3
46.1
5.5
1.2
3.4
1.1
1.3
0.01
0.01
2.2
2.2
0.3
Source: DWRPIS, 2007
108
2.1
1.5
3.0
TCVN
(5944-1995)
5.0
(mg/L)
0.05
(mg/L)
1.0
(mg/L)
0.01
(mg/L)
Industrial wastewater discharge into irrigation systems in HCMC
Figure F1: Wastewater of LMX IP
discharge into Canal 8, Binh Chanh
District
Figure F2: Wastewater discharge of Tan
Phu Trung IP into Thay Cai Canal, Hoc
Mon District
Figure F3: Wastewater discharge from
factories into Canal 1, Tan Tao Ward,
Binh Chanh District
Figure F5: Surface water pollution of
Canal B in Binh Chanh District
Figure F6: Surface water pollution of
Dua Canal in District 12
Figure F7: Surface water pollution of Ba
Hom Canal, Binh Tri Dong Ward, Binh
Tan District
Figure F8: Surface water pollution of
Canal 1, Tan Tao Ward, Binh Chanh
District
Figure F9: Surface water pollution of
Tran Quang Co canal, Hiep Thanh
Ward, District 12
Figure F10: Have to ground water for
vegetable Tan Hiep Ward, District 12 due
to Tran Quang Co canal pollution
Figure F11: Use rain water due to canal 1
pollution in Tan Tao Ward, Binh Chanh
District
Figure F12: Stored rainwater for next
crop in pond in Tan Tao, Binh Chanh
District
Figure F13: One crop per year due to only
using Rain water, in Xuan Thoi Thuong,
Hoc Mon District
109
Figure F14: No water for rice in dry season in Tan Tao Ward,
Binh Chanh District
Figure F15: Soil fallow in dry season in Le Minh Xuan Ward,
Binh Chanh District
Figure F16 (a) and F16 (a): Directly collected water from polluted canal B for rice farm in dry season, Binh Chanh District
Figure F17 (a) and F17 (b): Directly collected water from polluted canal B for farm in dry season, Binh Chanh District
Figure F18 and F19: Growing water morning glory in wastewater in Tan Tao, Binh Chanh Distrcit and Binh Tri Dong, Binh Tan
District
110
Figure F20: Xang River, Tan Nhut, Binh
Chanh District
Figure F20: An Ha canal, Hoc Mon District
Figure F21: Dong canal, Cu Chi
District
Figure F22: Rice affected by wastewater
(yellow leaves) in Le Minh Xuan Ward, Binh
Chanh District
Figure F23: Poor quality and low yield of rice
Le Minh Xuan Ward, Bhinh Chanh District
Figure 24: Change using purpose of
soil from rice growth to duckweed, in
Tan tao, Binh Chanh
Figure F25: Soil Fallow due to high pollution
in Tan Tao Ward, Binh chanh District
Figure F26:
Cr concentration at 4 monitoring points in Nha
Be-Binh Chanh region
Figure F27: Cu concentration at 4
monitoring points in Nha Be-Binh
Chanh region
Figure F28: As concentration at 4 monitoring
points in Nha Be-Binh Chanh region
Figure F29: Hg concentration at 4 monitoring
points in Nha Be-Binh Chanh region
111
APPENDIX G
Photos of effects of untreated industrial wastewater on farmer health in HCMC
Figure G1: Protection of farmer health
with plastic cloths in Binh Tri Dong,
Binh Tan District
Figure G2: Protection of farmer health
with plastic cloths in Tan Tao, Binh
Chanh District
Figure G4: Eye affected by water
pollution in Sang Canal, Xuan Thoi
Thuong, Hoc Mon District
Figure G5: Flooding in rain season with
water pollution cover around farmer
houses in Tan Tao, Binh Chanh District
112
Figure G3: Protection of farmer
health with plastic cloths in Dong
Xuan, District 12
APPENDIX H
10TCN 442-2001, concentration of heavy metals in vegetable (Vietnam)
10TCN 442-2001
Table H1: Concentration of heavy metals in vegetable
Element
Concentration
(mg/kg )
1
2
30
40
40
0.05
1
1
As
Pb
Cu
Sn
Zn
Hg
Cd
Sb
113
APPENDIX I
Calculation sample (A-MBR)
Flow rate
Membrane area (A) = 1.6 m2
Flux = 30 L/m2.h
Flow rate (out) = 30 L/m2.h * 1.6 m2 = 48 L/h = 1.152 m3/d
Flux = 45 L/m2.h
Flow rate (out) = 45 L/m2.h * 1.6 m2 = 72 L/h = 1.728 m3/d
Volume Bioreactor at OLR3 (Initial calculation with S0 = 350 mg/L)
Diagram of bioreactor = 0.85 m
Area of bioreactor tank = r2 * 3.14 = (0.85/2)2 * 3.14 = 0.567 m2
V3 = (Q3 * COD)/OLR3 = (1.728 m3/d * 0.35 kg/m3)/3.2 kg COD/m3.d = 0.19 m3 = 190 L
Height of bioreactor tank = V3/S = 0.19 m3 / 0.567 m2 = 0.33 m
OLR (With change of COD concentration during operating time at site)
S1 (OLR1) = 303 mg/L = 0.303 kg/m3, S2 (OLR2) = 724 mg/L = 0.724 kg/m3, S3 (OLR3) =
450 mg/L = 0.45 kg/m3
V1 = V2 = 220 L = 0.22 m3
OLR1 = (Q1 * COD)/V1 = (1.152 m3/d * 0.350 kg/m3)/0.22 m3 = 1.8 kg COD/m3.d
OLR2 = (Q2 * COD)/V2 = (1.728 m3/d * 0.724 kg/m3)/0.22 m3 = 5.7 kg COD/m3.d
OLR3 = (Q3 * COD)/V3 = (1.728 m3/d * 0.450 kg/m3)/0.19 m3= 4.1 kg COD/m3.d
HRT
HRT1 = V1/Q1 = 220 L / 48 L/h = 4.2 h
HRT2 = V2/Q2 = 220 L / 72 L/h = 3.1 h
HRT3 = V3/Q3 = 190 L / 72 L/h = 2.6 h
Daily getting out of sludge
OLR1 = OLR2 = V1/SRT = 220 L / 40 d = 6 L/d
OLR3 = V3/SRT = 190 L / 40 d = 5 L/d
F/M
MLSS (OLR1) = 6774 mg/L, MLSS (OLR2) = 7554 mg/L and MLSS (OLR3) = 8737
mg/L
F/M (OLR1) = 0.27 (day -1); F/M (OLR2) = 0.75 (day -1) and F/M (OLR3) = 0.47 (day -1)
114
Membrane resistance of A-MBR:
Viscosity of water at 42oC, μ = 0.63*10-3 N.s/m2
Table I1: Flux and TMP variation of A-MBR membrane operating with tap water
Flux (L/h)
S = 1.6 m2
74
96
124
152
176
Filtration flux
(L/m2.h)
46.25
60
77.5
95
110
TMP
(kPa)
71.31
73.97
76.63
79.29
81.95
Figure I1: TMP vs Flux of A-MBR membrane
Rm=0.1634kPa/(L/m2.h)*103kPa/Pa*3600s/h*1000L/m3/0.63*10-3Ns/m2 = 2.313*1012 m1
115
Membrane resistance of UF membrane:
Viscosity of water at 30oC, μ = 0.798*10-3 N.s/m2
Table I2: Flux and TMP variation of UF membrane operating with tap water
Flux (L/min)
S = 6.2 m2
96.77
116.13
135.48
154.84
174.19
Filtration flux
L/m2.h
10
12
14
16
18
TMP
kPa
48.39
58.06
67.74
77.42
87.10
Figure I2:TMP vs Flux of UF membrane
Rm=0.248kPa/(L/m2.h)*103kPa/Pa*3600s/h*1000L/m3/0.798*10-3Ns/m2 = 1.119*1012 m1
116
APPENDIX J
Results of pH, DO, Temperature and MLSS for bioreactor tank of A-MBR system
Table J1: DO, pH and Temperature variation of aerial tank during OLR1 and OLR2
period
Date
OLR 1.8 kg COD/m3.d
10/06/2010
10/09/2010
10/11/2010
10/14/2010
10/20/2010
10/25/2010
10/27/2010
10/31/2010
11/01/2010
11/04/2010
11/13/2010
11/14/2010
11/15/2010
11/16/2010
OLR 5.7 kg COD/m3.d
11/07/2010
11/08/2010
11/09/2010
11/11/2010
11/13/2010
11/15/2010
11/18/2010
12/23/2010
12/25/2010
12/26/2010
12/28/2010
12/30/2010
01/01/2011
01/03/2011
01/04/2011
01/07/2011
01/10/2011
01/12/2011
01/15/2011
01/17/2011
01/18/2011
01/20/2011
Day
DO
(mg/L)
pH
Temp
(oC)
7
10
12
15
21
26
28
32
33
36
45
46
47
48
7.47
7.71
6.87
6.95
6.35
6.86
5.25
4.95
4.65
5.33
6.23
6.14
5.25
5.22
7.71
7.75
7.87
7.07
8.22
6.58
7.85
7.85
7.40
7.91
7.32
7.60
8.08
8.14
42
41
37
37
42
42
42
41
42
37
38
40
40
42
69
70
71
73
75
77
80
85
87
88
90
92
94
96
97
100
103
105
108
110
111
113
5.51
5.13
5.18
5.24
4.49
5.35
5.15
5.27
5.32
5.43
5.36
4.37
4.28
4.53
4.61
4.53
4.62
4.56
4.53
4.99
4.66
4.25
8.17
7.92
8.03
8.06
8.22
8.23
8.14
7.89
7.74
8.03
8.20
7.65
7.73
7.95
8.12
7.86
7.68
7.94
7.78
7.45
8.13
7.56
38
38
37
40
38
40
40
40
40
40
40
40
40
40
40
40
39
40
38
37
37
37
117
Table J2: DO, pH and Temperature variation of aerial tank during OLR3 period
Date
OLR 4.1 kg COD/m3.d
01/22/2011
01/23/2011
01/24/2011
01/26/2011
02/08/2011
02/09/2011
02/10/2011
02/11/2011
02/12/2011
02/13/2011
02/14/2011
02/16/2011
02/18/2011
02/19/2011
02/21/2011
02/22/2011
02/28/2011
03/01/2011
03/05/2011
03/07/2011
03/08/2011
03/14/2011
03/15/2011
03/17/2011
03/19/2011
03/20/2011
Day
DO
(mg/L)
pH
Temp
(oC)
115
116
117
119
132
133
134
135
136
137
138
140
142
143
145
146
152
153
157
159
160
166
167
169
171
172
4.63
4.67
4.59
4.71
4.29
4.86
5.01
4.92
4.87
4.53
4.31
4.15
4.56
4.47
4.28
4.63
4.12
4.32
4.45
4.31
4.28
4.32
4.26
4.28
-
7.92
8.04
7.43
7.68
8.02
7.92
7.63
7.56
7.89
7.43
7.63
7.92
8.13
7.78
7.63
7.76
7.82
7.84
7.86
7.78
7.83
7.62
8.20
7.87
-
40
40
40
40
40
40
40
40
40
40
40
39
40
37
40
40
40
40
40
40
40
40
40
40
40
40
118
Table J3: MLSS of variation of aerial tank during three OLRs period
Date
OLR 1.8 kg COD/m3.d
10/05/2010
10/07/2010
10/12/2010
10/14/2010
10/19/2010
10/21/2010
10/24/2010
10/29/2010
11/03/2010
11/08/2010
11/10/2010
11/18/2010
OLR 5.7 kg COD/m3.d
11/24/2010
11/26/2010
12/01/2010
12/03/2010
12/08/2010
12/10/2010
12/14/2010
12/19/2010
01/12/2011
01/18/2011
01/21/2011
OLR 4.1 kg COD/m3.d
01/27/2011
02/15/2011
02/23/2011
03/02/2011
03/04/2011
03/09/2011
03/11/2011
03/18/2011
03/23/2011
Day
MLSS
(mg/L)
1
3
8
10
15
17
20
25
30
35
37
45
7,050
7,250
7,000
7,650
7,400
6,900
6800
6,700
6,100
6,450
6,480
6,450
51
53
58
60
65
67
71
76
100
106
109
7,450
7,240
7,250
7,350
7,050
7,200
6,950
7,350
7,950
8,300
8,700
115
134
142
149
151
156
158
165
170
8,650
8,500
8,500
8,500
8,500
8,500
8,650
8,700
9,050
119
APPENDIX K
TMP results of A-MBR and UF membrane systems
Table K1: TMP variation of A-MBR membrane during OLR1 and OLR2 period
Date
Day
TMP
OLR 1.8 kg COD/m3.d
09/30/2010
1
51.67
10/06/2010
7
51.67
100/9/2010
10
53.00
10/11/2010
12
53.00
10/14/2010
15
53.00
10/20/2010
21
53.00
10/25/2010
26
53.00
10/27/2010
28
53.00
10/31/2010
32
53.00
11/01/2010
33
53.00
11/04/2010
36
53.00
11/05/2010
37
53.00
11/13/2010
45
55.66
11/14/2010
46
55.66
11/15/2010
47
55.66
11/16/2010
48
55.66
3
OLR 5.7 kg COD/m .d
12/07/2010
69
48.73
12/08/2010
70
48.73
12/09/2010
71
50.33
12/11/2010
73
50.33
12/13/2010
75
50.33
12/15/2010
77
50.33
12/18/2010
80
50.33
12/23/2010
85
55.50
12/25/2010
87
55.50
12/26/2010
88
55.50
12/28/2010
90
55.50
12/30/2010
92
58.16
01/01/2011
94
58.16
01/03/2011
96
50.33
01/04/2011
97
50.33
01/07/2011
100
32.67
01/10/2011
103
32.67
01/12/2011
105
32.67
01/15/2011
108
36.33
01/17/2011
110
37.00
01/18/2011
111
37.67
01/20/2011
113
37.67
Pin
(Mpa)
Pin
(kPa)
Pout
(cm Hg)
Pout
(kPa)
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
-5.0
-5.0
-6.0
-6.0
-6.0
-6.0
-6.0
-6.0
-6.0
-6.0
-6.0
-6.0
-8.0
-8.0
-8.0
-8.0
-6.7
-6.7
-7.9
-7.9
-7.9
-7.9
-7.9
-7.9
-7.9
-7.9
-7.9
-7.9
-10.6
-10.6
-10.6
-10.6
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.01
0.01
0.01
0.01
0.01
0.01
100
100
100
100
100
100
100
105
105
105
105
105
105
100
100
70
70
70
80
80
80
80
-2.8
-2.8
-4.0
-4.0
-4.0
-4.0
-4.0
-6.0
-6.0
-6.0
-6.0
-8.0
-8.0
-4.0
-4.0
-2.0
-2.0
-2.0
-1.0
-1.5
-2.0
-2.0
-3.7
-3.7
-5.3
-5.3
-5.3
-5.3
-5.3
-7.9
-7.9
-7.9
-7.9
-10.6
-10.6
-5.3
-5.3
-2.6
-2.6
-2.6
-1.3
-1.9
-2.6
-2.6
120
Table K2: TMP variation of A-MBR membrane during OLR3 period
Date
Day
OLR 4.1 kg COD/m3.d
01/22/2011
115
01/23/2011
116
01/24/2011
117
01/26/2011
119
02/08/2011
132
02/09/2011
133
02/10/2011
134
02/11/2011
135
02/12/2011
136
02/13/2011
137
02/14/2011
138
02/16/2011
140
02/18/2011
142
02/19/2011
143
02/21/2011
145
02/22/2011
146
02/28/2011
152
03/01/2011
153
03/05/2011
157
03/07/2011
159
03/08/2011
160
03/14/2011
166
03/15/2011
167
03/17/2011
169
03/19/2011
171
03/20/2011
172
03/21/2011
173
03/22/2011
174
03/24/2011
176
TMP
(kPa)
Pin
(Mpa)
Pin
(kPa)
Pout
(cm Hg)
Pout
(kPa)
36.33
36.33
37.67
37.67
37.67
37.67
37.67
37.67
37.67
77.67
77.67
77.67
77.67
77.67
77.67
87.67
87.67
87.67
87.67
87.67
87.67
87.67
87.67
67.67
67.67
67.67
77.67
77.67
77.67
0.08
0.08
0.08
0.08
0.08
0.08
0.08
0.08
0.08
0.16
0.16
0.16
0.16
0.16
0.16
0.18
0.18
0.18
0.18
0.18
0.18
0.18
0.18
0.14
0.14
0.14
0.16
0.16
0.16
80
80
80
80
80
80
80
80
80
160
160
160
160
160
160
180
180
180
180
180
180
180
180
140
140
140
160
160
160
-1.0
-1.0
-2.0
-2.0
-2.0
-2.0
-2.0
-2.0
-2.0
-2.0
-2.0
-2.0
-2.0
-2.0
-2.0
-2.0
-2.0
-2.0
-2.0
-2.0
-2.0
-2.0
-2.0
-2.0
-2.0
-2.0
-2.0
-2.0
-2.0
-1.3
-1.3
-2.6
-2.6
-2.6
-2.6
-2.6
-2.6
-2.6
-2.6
-2.6
-2.6
-2.6
-2.6
-2.6
-2.6
-2.6
-2.6
-2.6
-2.6
-2.6
-2.6
-2.6
-2.6
-2.6
-2.6
-2.6
-2.6
-2.6
121
Table K3: TMP variation of UF membrane before adding Sand filtration
Date
10/25/2010
10/27/2010
10/31/2010
11/01/2010
11/04/2010
11/05/2010
11/13/2010
11/14/2010
11/15/2010
11/16/2010
12/07/2010
12/08/2010
12/09/2010
12/11/2010
12/13/2010
12/15/2010
12/18/2010
12/23/2010
12/25/2010
12/26/2010
12/28/2010
12/30/2010
01/01/2011
01/03/2011
01/10/2011
01/12/2011
01/15/2011
01/17/2011
01/18/2011
01/20/2011
Day
26
28
32
33
36
37
45
46
47
48
69
70
71
73
75
77
80
85
87
88
90
92
94
96
103
105
108
110
111
113
TMP
(kPa)
9.81
9.81
9.81
9.81
9.81
9.81
14.71
14.71
9.81
122.59
9.81
9.81
14.71
9.81
24.52
24.52
9.81
24.52
9.81
24.52
39.23
24.52
24.52
73.55
9.81
24.52
9.81
34.33
9.81
24.52
122
Pin
(kg/cm2)
0.2
0.2
0.2
0.2
0.2
0.2
0.3
0.3
0.2
2.5
0.2
0.2
0.3
0.2
0.2
0.3
0.2
0.5
0.2
0.3
0.8
0.3
0.5
1.5
0.2
0.3
0.2
0.7
0.2
0.5
Pin
(kPa)
19.61
19.61
19.61
19.61
19.61
19.61
29.42
29.42
19.61
245.17
19.61
19.61
29.42
19.61
49.03
49.03
19.61
49.03
19.61
49.03
78.45
49.03
49.03
147.10
19.61
49.03
19.61
68.65
19.61
49.03
Table K4: TMP variation of UF membrane after adding Sand filtration
Date
01/22/2011
01/23/2011
01/24/2011
01/26/2011
02/08/2011
02/09/2011
02/10/2011
02/11/2011
02/12/2011
02/13/2011
02/14/2011
02/16/2011
02/18/2011
02/19/2011
02/21/2011
02/22/2011
02/28/2011
03/01/2011
03/05/2011
03/07/2011
03/08/2011
03/14/2011
03/15/2011
03/17/2011
03/19/2011
03/20/2011
03/21/2011
03/22/2011
03/24/2011
Day
115
116
117
119
132
133
134
135
136
137
138
140
142
143
145
146
152
153
157
159
160
166
167
169
171
172
173
174
176
TMP
(kPa)
9.81
14.71
14.71
9.81
14.71
14.71
9.81
14.71
14.71
9.81
14.71
19.61
9.81
34.32
9.81
19.61
24.52
9.81
19.61
9.81
14.71
24.52
9.81
14.71
19.61
9.81
14.71
19.61
9.81
Pin
(kg/cm2)
0.2
0.3
0.3
0.2
0.3
0.3
0.2
0.3
0.3
0.2
0.3
0.4
0.2
0.5
0.2
0.4
0.5
0.2
0.4
0.2
0.3
0.5
0.2
0.3
0.4
0.2
0.3
0.4
0.2
123
Pin
(kPa)
19.61
29.42
29.42
19.61
29.42
29.42
19.61
29.42
29.42
19.61
29.42
39.23
19.61
68.65
19.61
39.23
49.03
19.61
39.23
19.61
29.42
49.03
19.61
29.42
39.23
19.61
29.42
39.23
19.61
APPENDIX L
Treated water quality of CAS, A-MBR and UF processes
Table L1: Detail Data of pH feed and treated water quality of CAS process and
membrane systems during operating time
pH of Feed
Day water
OLR 1.8 kg COD/m3.d
1
8.02
3
7.70
8
7.54
10
7.63
15
7.30
20
7.78
22
7.40
24
7.35
30
7.89
34
7.65
OLR 5.7 kg/COD/m3.d
36
7.69
38
7.73
43
7.66
45
7.77
50
7.68
52
7.77
56
7.64
59
7.82
66
7.76
73
8.00
85
87
7.48
91
7.11
93
7.23
94
7.60
OLR 4.1 kg COD/m3.d
98
7.93
100
7.27
119
7.31
121
7.60
127
7.53
129
7.77
134
7.49
136
7.74
141
7.39
143
8.61
148
7.12
150
7.25
155
7.23
157
7.39
pH of CAS
effluent
pH of MBR
permeate
pH of UF
permeate
7.94
7.40
7.41
7.18
7.14
7.39
7.10
6.87
7.33
7.07
8.01
7.70
7.90
7.53
7.79
8.04
7.80
7.69
6.86
7.67
7.51
7.37
7.46
7.15
7.23
7.31
7.23
6.95
7.12
7.41
7.50
7.40
7.48
7.80
7.33
7.55
7.76
7.60
7.44
8.09
7.35
7.63
7.04
7.26
7.19
8.19
8.30
7.69
7.34
7.69
7.81
7.64
7.45
7.44
8.36
7.30
7.47
7.53
7.57
7.55
7.61
7.38
7.63
7.59
7.41
7.95
7.87
7.68
7.42
8.14
7.25
7.48
7.05
7.22
7.21
8.36
6.63
7.27
7.42
7.42
7.36
7.51
8.04
8.10
8.83
7.95
7.52
7.56
7.40
8.37
7.81
7.91
7.89
8.00
7.90
7.94
8.73
7.52
8.14
8.40
8.04
7.89
8.40
7.76
7.41
7.33
7.29
7.45
7.43
7.55
8.15
7.38
8.46
8.07
7.65
7.48
7.45
124
Table L2: Detail Data of COD feed and treated water quality of CAS process and
membrane systems during operating time, COD removal efficiency during three
different organic loading rates (OLR).
Da
y
Feed
water
Effluent Permeate Permeat
COD of COD of e COD
CAS
MBR
of UF
(mg/
L)
(mg/L)
(mg/L)
OLR1.8 kg COD/m3.d
1
380
79
45
3
385
65
61
8
203
63
75
10
97
44
30
15
269
49
64
20
277
51
47
22
288
73
73
24
434
83
35
30
379
65
38
34
322
56
88
3
OLR 5.7 kg COD/m .d
36
976
100
24
43 1219
83
53
50
349
150
94
56
372
73
66
59
482
90
24
66
234
72
45
73
350
116
17
85 1241
124
26
87
748
94
63
91 1023
116
57
93
976
132
85
OLR 4.1 kg COD/m3.d
98
256
83
64
100 560
77
64
119 648
114
74
121 464
80
51
127 352
74
22
129 464
74
32
134 616
78
35
136 472
80
64
141 256
110
96
148 256
64
61
155 496
102
70
157 368
128
51
Removal
Efficiency
of CAS
Removal
Efficiency
of MBR
Removal
Efficiency
of UF
(mg/L)
(%)
(%)
(%)
60
51
43
8
28
36
62
46
57
40
79.20
83.02
68.97
54.64
81.62
81.59
74.65
80.88
82.85
82.61
88.16
84.15
63.05
69.07
76.21
83.03
74.65
91.94
89.97
72.67
23.08
22.22
31.75
81.82
44.11
29.41
15.07
44.58
12.31
28.57
65
68
77
63
85
54
103
107
79
85
101
89.75
93.19
57.02
80.38
81.37
69.23
66.86
90.01
87.37
88.62
86.45
97.54
95.65
73.07
82.26
94.99
80.77
95.14
97.90
91.58
94.46
91.29
35.00
18.07
48.67
13.70
5.09
25.00
11.21
13.71
16.67
27.03
23.81
70
72
90
77
66
61
53
75
93
51
96
99
67.58
86.25
82.41
82.76
78.98
84.05
87.27
83.05
56.88
75.00
79.35
65.22
75.00
88.57
88.58
89.01
93.75
93.10
94.29
86.44
62.50
76.25
85.81
86.09
15.66
6.49
21.05
3.75
10.81
17.57
32.65
6.00
15.94
20.31
6.25
22.50
125
Table L3: Average COD of feed water and treated water quality of CAS, A-MBR and UF processes, and % removal of COD
Average and
standard
deviation
Average
OLR =1.8
3
kg COD/m .d
STDEV
Average
OLR =5.7
3
kg COD/m .d
STDEV
Average
OLR =4.1
3
STDEV
kg COD/m .d
STDEV: Standard deviati
OLR
Feed
water
(mg/L)
303
100
724
378
450
132
CAS
A-MBR
UF
(mg/L)
63
13
105
25
91
19
(mg/L)
56
19
50
26
57
21
(mg/L)
43
17
81
18
77
15
126
Remove of
CAS
(%)
77
9
81
12
78
10
Remove of
A-MBR
(%)
79
10
90
8
86
9
Remove of
UF
(%)
33
20
22
12
14
9
Table L4: Detail Data of SS treated water quality of CAS process and membrane
systems during operating time, SS removal efficiency during three different organic
loading rates (OLR).
SS
effluent
of CAS
(mg/L)
(mg/L)
OLR1.8 kg COD/m3.d
1
60
40
3
30
10
8
80
20
10
128
16
15
30
10
20
50
20
22
30
10
24
25
10
30
120
10
34
80
20
OLR 5.7 kg COD/m3.d
36
125
30
38
20
10
43
20
10
45
20
10
50
30
10
52
80
50
56
140
50
59
60
20
66
20
20
73
30
10
85
50
10
87
50
10
91
40
20
93
60
10
94
30
20
OLR 4.1 kg COD/m3.d
98
120
30
100
113
20
119
60
35
121
145
20
127
40
20
129
67
10
134
85
20
136
67
20
141
66
27
143
50
20
148
40
40
150
40
20
155
50
20
157
40
20
Day
SS of
influent
SS of
MBR
permeate
(mg/L)
SS of UF
permeate
(mg/L)
Removal
Efficiency of
CAS
(%)
Removal
Efficiency of
MBR
(%)
Removal
Efficiency of
UF
(%)
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
33.33
66.67
75.00
87.50
66.67
60.00
66.67
60.00
91.67
75.00
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
76.00
50.00
50.00
50.00
66.67
37.50
64.29
66.67
0.00
66.67
80.00
80.00
50.00
83.33
33.33
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
75.00
82.30
41.67
86.21
50.00
85.07
76.47
70.00
59.09
60.00
0.00
50.00
60.00
50.00
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
127
Table L5: Detail Data of Color treated water quality of CAS process and membrane
systems during operating time, color removal efficiency during three different
organic loading rates.
Color of
CAS
effluent
(Pt-Co)
(Pt-Co)
OLR 1.8 kg COD/m3.d
1
482
182
3
351
163
8
290
145
10
338
147
15
277
106
20
215
148
22
528
112
24
541
135
30
1945
117
34
409
95
OLR 5.7 kg COD/m3.d
36
2,315
168
38
1,925
146
43
381
130
45
411
151
50
2,000
144
52
452
189
56
815
191
59
570
144
66
960
202
73
318
159
85
867
122
87
1,280
142
91
228
143
93
521
110
94
322
180
OLR 4.1 kg COD/m3.d
98
237
128
100
1,160
128
119
1,240
94
121
990
152
127
1,570
527
129
1,380
232
134
940
158
136
310
196
141
359
176
143
528
176
148
347
204
150
286
194
155
396
136
157
484
166
Day
Color
influent
Color of
MBR
permeate
(Pt-Co)
Color of
UF
permeate
(Pt-Co)
Removal
Efficiency of
CAS
(%)
Removal
Efficiency of
MBR
(%)
Removal
Efficiency
of UF
(%)
124
147
143
141
123
163
135
88
39
93
102
137
130
117
99
139
108
126
90
91
62.24
53.56
50.00
56.51
61.73
31.16
78.79
75.05
93.98
76.77
74.27
58.12
50.69
58.28
55.60
24.19
74.43
83.73
97.99
77.26
43.96
15.95
10.34
20.41
6.60
6.08
3.57
6.67
23.08
4.21
58
89
116
54
88
128
172
137
50
133
35
74
120
55
131
148
121
67
135
130
151
140
124
178
133
114
135
133
97
174
92.74
92.42
65.88
63.26
92.80
58.19
76.56
74.74
78.96
50.00
85.93
88.91
37.28
78.89
44.10
97.49
95.38
69.55
86.86
95.60
71.68
78.90
75.96
94.79
58.18
95.96
94.22
47.37
89.44
59.32
11.90
17.12
48.46
10.60
9.72
20.11
26.70
13.89
11.88
16.35
6.56
4.93
6.99
11.82
3.33
110
123
74
64
140
61
71
146
183
183
147
161
153
154
113
126
94
146
262
148
137
165
160
168
154
128
128
136
45.99
88.97
92.42
84.65
66.43
83.19
83.19
36.77
50.97
66.67
41.21
32.17
65.66
65.70
53.59
89.40
94.03
93.54
91.08
95.58
92.45
52.90
49.03
65.34
57.64
43.71
61.36
68.18
11.72
1.56
0.00
3.95
50.28
36.21
13.29
15.82
9.09
4.55
24.51
34.02
5.88
18.07
128
Table L6: Average color of feed water and treated water quality of, CAS, A-MBR and UF processes, and % removal of color
Average and
standard
deviation
Average
OLR 1.8
3
kg COD/m .d
STDEV
Average
OLR 5.7
3
kg COD/m .d
STDEV
Average
OLR 4.1
3
STDEV
kg COD/m .d
STDEV: Standard deviation
OLR
Feed
water
(Pt-Co)
538
506
891
682
731
464
CAS
A-MBR
UF
(Pt-Co)
135
27
155
27
191
103
(Pt-Co)
120
37
96
41
126
43
(Pt-Co)
114
18
132
27
148
39
129
Remove of
CAS
(%)
64
18
72
18
65
20
Remove of
A-MBR
(%)
65
21
81
16
72
20
Remove of
UF
(%)
14
13
15
11
16
15
Table L7: Detail Data of conductivity treated water quality of CAS process and
membrane systems during operating time, conductivity removal efficiency during three
different organic loading rates.
Cond of
CAS
effluent
(mS/cm)
(mS/cm)
OLR 1.8 kg COD/m3.d
1
5.06
4.80
3
4.95
4.52
8
5.30
4.77
10
4.41
4.33
15
5.20
4.60
20
5.35
4.57
22
4.60
4.20
24
5.80
5.20
30
5.40
4.70
34
4.14
3.76
OLR 5.7 kg COD/m3.d
36
5.70
4.80
38
4.80
4.30
43
4.00
3.30
45
5.79
4.84
50
4.40
4.20
52
4.97
4.46
56
5.40
5.00
59
5.20
4.70
66
4.80
4.38
73
5.28
4.90
85
4.25
3.50
91
4.00
3.90
93
4.00
4.00
94
5.20
4.30
OLR 4.1 kg COD/m3.d
98
4.40
3.60
100
4.00
3.50
119
4.30
3.70
121
4.56
4.32
127
4.09
3.65
129
4.30
3.40
134
4.77
4.23
136
5.16
4.28
141
5.15
4.75
143
4.95
3.87
148
3.97
3.12
150
4.23
4.14
155
4.17
3.97
157
4.86
4.52
Day
Cond of
influent
Cond of
MBR
permeate
(mS/cm)
Cond of
UF
permeate
(mS/cm)
Removal
Efficiency
of CAS
(%)
Removal
Efficiency of
MBR
(%)
Removal
Efficiency
of UF
(%)
4.92
4.62
5.01
4.30
4.90
5.10
4.60
3.50
2.70
3.66
4.74
4.26
4.75
4.28
4.60
4.46
3.90
5.00
4.20
3.65
5.14
8.69
10.00
1.81
11.54
14.58
8.70
10.34
12.96
9.18
2.77
6.67
5.47
2.49
5.77
4.67
0.00
39.66
50.00
11.59
1.25
5.75
0.42
1.15
0.00
2.41
7.14
3.85
10.64
2.93
2.40
2.70
3.30
4.70
2.70
3.47
5.30
4.50
1.66
4.94
3.40
4.00
2.80
4.00
4.70
4.30
2.20
4.44
4.00
4.36
4.80
4.60
4.30
4.72
3.30
3.70
3.80
4.20
15.79
10.42
17.50
16.41
4.55
10.26
7.41
9.62
8.75
7.20
17.65
2.50
0.00
17.31
57.89
43.75
17.50
18.83
38.64
30.18
1.85
13.46
65.42
6.44
20.00
0.00
30.00
23.08
2.08
0.00
33.33
8.26
4.76
2.24
4.00
2.13
1.83
3.67
5.71
5.13
5.00
2.33
3.50
3.60
3.40
3.00
3.62
2.70
2.51
3.66
4.88
4.62
3.04
4.02
3.87
4.44
3.50
3.50
3.40
4.31
3.65
3.20
4.23
3.74
4.32
3.72
3.08
3.73
3.95
4.51
18.18
12.50
13.95
5.26
10.76
20.93
11.32
17.05
7.77
21.82
21.41
2.13
4.80
7.00
20.45
10.00
20.93
34.21
11.49
37.21
47.38
29.07
5.24
6.67
23.43
4.96
7.19
8.64
2.78
0.00
8.11
0.23
0.00
5.88
0.00
12.62
9.05
3.88
1.28
9.90
0.50
0.22
130
Table L8: Detail Data of UV254 nm of membrane systems during three different
organic loading rates.
Day
UV 254 nm of MBR
(m-1)
OLR 1.8 kg COD/m3.d
3
0.993
8
0.973
10
0.943
15
0.792
0.889
20
0.793
22
0.587
24
OLR 5.7 kg COD/m3.d
36
38
43
50
52
87
91
94
OLR 4.1 kg COD/m3.d
121
125
134
141
143
148
150
155
157
0.309
0.412
0.596
0.490
0.755
UV 254 nm of UF
(m-1)
0.907
0.855
0.793
0.647
0.741
0.637
0.765
0.846
0.625
0.310
0.731
0.321
0.774
0.831
0.980
0.860
0.824
0.891
0.950
0.968
0.925
0.914
0.943
0.935
0.582
0.936
0.927
0.830
0.940
0.998
0.954
0.914
0.919
0.974
0.961
0.915
131
Table L9: Detail Data of BOD5 treated water quality of CAS process and membrane
systems during operating time
Feed BOD5
(mg/L)
OLR 1.8 kg COD/m3.d
10/11/2010
132
22/11/2010
138
3
OLR 5.7 kg COD/m .d
08/12/2010
175
17/12/2010
198
12/01/2010
201
OLR 4.1 kg COD/m3.d
23/02/2010
186
01/03/2011
216
16/03/2011
216
18/03/2011
138
BOD5 of CAS
effluent
(mg/L)
BOD5 of MBR
permeate
(mg/L)
BOD5 of UF
permeate
(mg/L)
17
16
12
10
13
12
18
18
16
15
14
13
15
15
14
20
18
18
16
18
10
10
13
18
16
16
14
Table L10: Detail Data of total coliform, E.coli and heavy metals (Zn, Ni, Cd, Cr) treated
water quality of CAS process and membrane systems during operating time during
three different organic loading rates.
Total coliform
E.coli
Zn
Ni
Cd
Cr
MPN/100mL
MPN/100mL
(mg/L)
(mg/L)
(mg/L)
(mg/L)
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
3
OLR 1.8 kg COD/m .d
PS
2.4*106
CAS
4.9 *103
A1.3 * 102
MBR
UF
3.3*101
OLR5.7 kg COD/m3.d
PS
1.7*104
CAS
A1.7*102
MBR
2.3*101
UF
OLR 4.1 kg COD/m3.d
PS
CAS
1.6*103
MBR
7.8*100
UF
2.0*100
Nd: Not detected
1.4*104
1.4*103
<1.8
0.56
0.43
0.49
0.19
<1.8
0.59
0.46
3.5*103
<1.8
0.07
0.11
2.20
0.09
<1.8
0.03
1.20
nd
nd
nd
nd
0.59
0.22
0.18
0.19
0.29
0.18
0.16
0.16
nd
nd
nd
nd
nd
nd
nd
nd
2
1.7*10
<1.8
<1.8
132
Appendix M
Table M1. Company list with Color and Conductivity in wastewater effluent in Le
Minh Xuan IP
No
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
Company
Tan Man Hung
Binh Minh
Hong Phuc
Sinh Kim
Gia Hoi
Dinh Hoang Dung
Duc Phu
HANDA
Kim Khi Thang Long
Dung Tien
G-M
SXGL Thuan Phat
Strong Way
Van Phuc Thanh
Dinh Ba Tien
Nguyen Khiem
Minh Tien
Tien Kim Thanh
Nguyen Thanh
Hong Chau
GC Thuan Phat
Long Phung
Hiep Phu Huy
Van Nga
Trong An
Linh Van
Loc Hiep Hoa
Ngoc Nhi
BB Thanh Dat
Buu dien Ha Noi
Nhom Thanh
Dai Phat
Hieu Hoa
Hoa Tho
Vinh Tan
Phuoc Hung
ATA
Ngoc Lan
Det Nhuom Thanh Phat
Production
Battery
Chemicals
Food production
Dyeing
Dyeing
Textile and dyeing
Dyeing
Motorcycle part
Mechanism
Dyeing
Battery
Dyeing
Motorcycle parts
Dyeing
Battery
Plating
Battery
Textile and dyeing
Plating
Battery
Dyeing
Food production
Plastic
Parking
Plating
Tanning
Pup and paper
Dyeing
packing
Plating
Plating
Alumium
Dyeing
Dyeing
Seafood production
Zinc production
Plating
Dyeing
Dyeing
133
Water
use
(m3/day)
12.8
35.1
10.5
55.2
28.7
24.2
17.6
19.5
42.3
16.1
2.1
1.6
3.8
49.0
16.3
2.4
Color
Conductivity
(Pt-Co)
(mS/cm)
69
339
1.04
2.19
0.83
0.93
16.7
1.29
2.97
2.91
1.28
1.86
0.60
2.84
0.69
0.89
0.70
7.45
2.40
6.07
1.90
1.35
3.99
1.20
2.14
1.30
2.03
52.9
2.0
1.0
1.4
8.42
0.4
0.9
1.9
1.4
1.7
1.9
2.9
1.67
3.7
1705
1780
750
1045
131
227
935
367
394
138
215
2160
37
1100
253
490
9
0.8
3.2
9
6.7
15.4
467
1023
9
No
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
Company
Le Phu
Hung Nghia
Phuoc Hai
An Giang
Tan Tien Cuong
Nguyen Quoc
Thang Loi
Long phung
Dat Thanh
Doan Thanh Phu
Viet Nhat
Quang Tien
Hua Hong
Jin Kyong VN
Ngoc Lan
BB Trung Son
Nguyen Quoc
Ho Bac
Nguyen Thanh
Phu Thuan
MT Quoc Viet
Nguyen Huu Tam
SHANG ONE
Đien Co Ha Noi
Nghiep Phong
Cong Nghiep
Lam Tung
Minh Anh
MINGUANG
Huy Phu
Dau Khí
Du Phat
Trung Thanh Hoa
Tan Tuong An
Tien Dung
Si Xang
Minh Thanh
Thien Long
Nguyen Hung
Uy Thanh
VT Sai Gon Printing
Dao Thu
Cuu Long
Production
Food production
Mechanism
Dyeing
Pesticide
Dyeing
Dyeing
Plating
Food production
Plating
Dyeing
Livestock food
Parking
Food production
Clothing and Wash
Textile and Dying
Parking
Dying
Cleaning chemical
Plating
Clothing
Environmental
Footwear production
Turbine
Inox tank
Animal food store
Textile and Dying
Plating
Dying
Wood
Dying
Chemical
Dying
Water
use
(m3/day)
10.3
Conductivity
(Pt-Co)
(mS/cm)
320
842
1843
23.2
1.59
2.07
15.84
1.1
4.0
0.62
1.31
1.29
0.65
1.53
1.7
1.0
0.9
0.6
0.7
2.9
2.4
2.6
0.3
0.6
1.4
0.9
1.2
0.5
0.5
1.4
2.0
1.0
0.3
1.4
1.4
1.2
1.4
2.1
1.0
1.3
0.6
0.5
1.0
0.5
0.7
0.9
19.7
3.6
1436
1.6
4.5
14.3
22.7
17.4
133.3
9
24.7
4.5
1.2
48.9
3.7
9.6
9
27.2
9
72.2
9
1.2
9
2.5
134
Color
No
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
Company
Phuoc Long
MT Xanh
Thinh Toan
Minh Nghi
Loi Van
Quang Tam
Anh Quan
Thanh Xuan Viet Nam
Hieu Hao
Vi Nam Viet
Tan Mau Hung
Tan Hoa Thinh
Dai Phat
Phuoc Hai
Hoa Tho
Bao Ve Thuc Vat
Tat Ba
Nguyen Hoang Sang
Hoa Binh
Phat Loi
Hoa Khanh
Ngoc Yen
ALFA Sai Gon
Truong To Ha
Hoa Chat Binh Minh
MT Viet Uc
Anh Phuong
Muc In TH
Hoang Thoai Vinh
Tan Diep Binh
Ngoc Tung
Hoa Lien Tien
Mekong TBD
Quang Minh
HL+DH
Fong Tai
Truong Minh
Gia Cuong Thinh
Phu Van Trung
Quang Tien
CTy Bong Binh Chanh
Hiep Hung
Cty Cao Su Doc Lap
Production
Water
use
(m3/day)
Textile and Dying
Waste treatment
66.4
Juice production
Plating
29.5
Mechanism
Textile and Dying
Battery
33.8
12.8
2.6
Aluminum
Dying
Dying
Pesticide
Plating
Copper & Aluminum
Pesticide
Plating
Dying
Pesticide
Pesticide
Plating
Chemical
Waste treatment
Pesticide
Food production
Rubber
Plating
Dying
Plating
Plating
Plating
Battery
Plating
Rubber
135
22.5
1.7
20.0
41.6
2.7
Color
Conductivity
(mS/cm)
(Pt-Co)
9
9
9
0.5
1.1
0.2
0.7
2.1
0.5
0.6
0.7
1.1
1.2
0.9
2.7
1.3
1.6
4.0
0.6
4.0
1.2
1.4
1.0
1.5
1.4
8.8
16.5
1.7
1.6
0.6
1.1
0.6
0.7
1.1
0.9
0.6
0.8
1.0
1.3
0.5
2.5
0.9
1.7
0.6
0.7
0.5
No
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
Company
Tan Hop
Phuong Nam
WuFeng
Hung Loi
Nhon Phong
Ho Bac
May Sai Gon
Han Chau
Huy Hao
Thien Vu (E-Den)
Nguyen Quoc
Tung Nguyet
Hong Phu
Vinh Hoa
Dang Thanh Son
Ngoc Tung
Thien Dong An
HD SG Viet Phat
Thanh Son
Dang Tu Ky
Nhan Thanh
Dai Phat
Thanh Son Hoa Nong
Huu Doanh
Yi Lin VN
Duc Thinh
TP Thuan Phat
CHUAN LIN
Du Phat
TAA View
Production
Water
use
(m3/day)
6.8
Food production
Footwear production
Fishing tool
Clothing and Wash
Battery
6.7
24.0
17.9
4.5
80.3
16.1
Dying
Cleaning barrel
Dying
Plastic
66.8
Dying
Mechanism
Tanning
Dying
Copper
Pesticide
324.8
29.0
11.3
Paper store
Food production
Textile and Dying
Note: 9 with high color
136
2.1
2.6
72.7
4.5
Color
Conductivity
(mS/cm)
(Pt-Co)
1.1
0.5
1.6
2.4
1.2
0.5
1.7
1.2
1.4
0.8
7.9
0.8
1.3
2.3
0.5
0.5
0.8
0.8
0.7
16.2
0.2
1.5
2.5
0.8
1.4
1.2
5.6
2.1
1.4
0.7