Japan and China Joint Symposium

Transcription

Japan and China Joint Symposium
Sustainable Sanitation and Environment and Human Health Risk Management
Date: October 15th, 2012
Venue: Hokkaido University Conference Hall (学術交流会館)
Organizers:

Main Organizer: Faculty of Engineering, Hokkaido University

Co-organizer: Xi’an University of Architecture & Technology, JST
Outline:
Poverty is considered to contribute to increased incidence of all waterborne diseases,
which in turn perpetuate and exacerbate the cycle of poverty. This symposium will
discuss solutions to water and sanitation problems around the world based on
achievements made by research groups in Japan and China on the Strategic
International Research Cooperative Program implemented by JST.
Language:
English
Program:
12:30-13:00: Registration
13:00-13:15: Opening Session


Welcome address by Prof. Naoyuki Funamizu (Faculty of Engineering, Hokkaido
University)
Opening address by Prof. Xiaochang Wang (Xi’an University of Architecture &
Technology)
13:15-14:00:Session1: Urine and its application (Chair: Mr. Charchalac Ochoa)

Moustapha Sene: Effect of Human Urine Application Volume in Komatsuna Growth

Shanqing Jiang: Characteristics of nitrogen and phosphorus absorption by soil particles
for urine disposal and fertilizer production

Hideaki Miyai: Investigation into determination method of anti-malarial drugs in
agricultural soil and plant assumed as human urine reuse
14:00-15:00:Session2: Pathogen and Toxicity (Chair: Ms.Zhang)

Shuji Ozawa: Detection, Quantification and Isolation of Escherichia coli O157 with Flow
Cytometry and Fluorescence-Activated Cell Sorting

Zhenzhen Yu: Comparison of strain culture and real-time PCR for identification of
Escherichia coli in environmental water

Takashi Yoshimura: Bacterial extracellular polymeric substances as a novel adsorbent for
human noroviruses

Maoni Wu: Comparison of bioassays using algae and luminescent bacteria for ecotoxicity
assessment of reclaimed water
15:00-15:30: Coffee Break
15:30-16:15:Session3:Gray & Wastewater Treatment (Chair: Mr. Sene)

Jialing Tang: Isolation and characterization of membrane fouling substances from a
membrane bioreactor

Sebastian Ignacio Charchalac Ochoa : Evaluation of Intermittent Sand Filtration
for Removal of Greywater-related Micropollutants

Yucong Zheng: Comparative study of constructed wetlands of various types for treating
polluted river water
16:15-17:15:Session4:Composting (Chair: Ms. Wu)

Qian Li : Characteristics of fecal organic decomposition and nitrogen transformation in an
aerobic composting reactor with sawdust as bulky matrix under two typical temperatures

Natsuru Yamauchi: Investigation on maturing period of compost from composting toilet

Yongmei Zhang: Anaerobic digestion of kitchen wastes for the production of carbon
source for a membrane bioreactor

Rui Tezuka: Inactivation mechanism of pathogenic bacteria using lime and ash in
composting toilet
17:15-17:45:Session5: Design (Chair: Mr. Yamauchi)

Yosuke Deguchi: Design of resource recycling sanitation system based on relationship
between fertilizer demand and potential supply of human excreta as fertilizer in
Indonesia

Kenta Yabui: Design of composting toilet for practical application in Burkina Faso
17:45-18:00 closing, photo session
*One presentation: 10minutes presentation followed by 5 minutes discussion
Effect of human urine application volume in Komatsuna
growth
Moustapha SENE*, Nowaki HIJIKATA*, Ken USHIJIMA*, Naoyuki FUNAMIZU*
1/2/3/4
Department of Environmental Engineering, Hokkaido University.
(Kita13,Nishi 8,Kita-ku,Sapporo-shi,Hokkaido,060-8628,Japan)
Keywords: Human urine, application volume, agriculture
Human urine contains large amount of nitrogen (N), phosphorus (P) and Potassium (K) and
can be reuse in agriculture in order to substitute industrial fertilizer. Nevertheless urine
contains some salts, pathogen and pharmaceuticals. Considered the salt issue, too much
urine application has a potential to inhibit plant growth, since it may cause too much sodium
and/or nitrogen accumulation in soil. Therefore, the objectives of this study were to
investigate the effect of human urine application volume in Komatsuna cultivation.
Pot test was conducted in greenhouse using sandy soil (a) and sandy soil mixed with chaff
charcoal compost (b) as media. Considered total nitrogen required to growth “Komatsuna” in
(a) (140 mg/pot) and in (b) (28.3 mg/pot). Diluted (1/3) synthetic urine volume application was
designed as V0 (34.8 mL/pot) for (a) and V0’ (7.0 mL/pot) for (b) in total 30 days cultivation., 3
different urine treatments volumes and 1 modified Hoagland solution volume (same amount N
with plant requirement), those defined as V0, 2V0, 3V0 and Vm-H were applied in different pots
in (a). In similar manner V0’, 2V0’, 3V0’, and Vm-H’ were applied in (b). Totally, 4 fertilizer
treatments were set in each media and control (5 case/media). 50 experimental pots were
used for 10 treatments with 5 replications per condition. Then, plant weight, N concentration
in shoot, root and soil were measured.
In shoot dry weight of (a), V0 (2.38±0.23 g), 2V0 (2.49±0.88 g), 3V0 (3.10.± 0.43 g) and Vm-H
(2.71±0.33 g) had no significant difference but significantly higher than control (0.28±0.23 g)
(Turkey Kramer, p<0.05). In the case of (b), shoot dry weight values (V0’) 5.32±0.73, (2V0’)
6.10±0.73, (3V0’) 5.87±0.68 and (Vm-H’) 5.51±0.31 were in the same level but only (2V0’) was
higher than (control’) 4.92±0.44 g. Furthermore, N concentration in shoot in (a) were
42.45±2.33 (V0), 63.75±6.22 (2V0), 80.40±1.83 (3V0), 31.74±2.43 (Vm-H) and 10.45±1.73 mg/g
plant dry weight (control) and significantly different among them. Besides in (a), N reminded in
soil after cultivation for the followed treatments V0, 2V0, Vm-H (0.16±0.02, 0.17±0.01, 014±0.02
mg/g plant dry weight, respectively) was in the same level and significantly lower than 3V0
(0.22±0.01 mg/g plant dry weight). Regarding the (b) case, N reminded in soil after cultivation
for all treatment included was statistically in the same level. Moreover in (b), N uptake in
shoot (V0’) 30.41±4.56, (2V0’) 31.57±1.47 and (3V0’) 34.41±3.88 mg/g plant dry weight were in
the same level but significantly higher than Vm-H’ (22.29±1.89 mg/g plant dry weight).
From the results, we concluded that urine volume had no effect for Komatsuna growth.
Moreover accumulation of N in soil was not observed. Perhaps, extra N and Na might be
leached from the pot in our experimental system. Furthermore, urine volume affects N
concentration of Komatsuna in soil (a) but not in soil (b). In soil (a) other nutrients (P or
micronutrients likewise Fe, Zn, B and so on) probably supply by compost in soil (b), may limit
Komatsuna growth.
-1-
-2-
Characteristics of nitrogen and phosphorus absorption by soil
particles for urine disposal and fertilizer production
#
S.Q. Jiang, X.C. Wang , C. Li
Key Lab of Northwest Water Resource, Environment and Ecology, MOE, Xi’an University of Architecture
and Technology, Xi’an 710055 China
(E-mail: [email protected])
Keywords: urine; nitrogen and phosphorus absorption; soil particles
Background and objectives
The current option about the dispose of human excreta is inadequacy for the reason that
flush-and-discharge systems require large amounts of water and many investments.
Ecological sanitation technology which claims to recover resources such as nutrients, water
and energy from human waste and wastewater would be a promising approach (Uno Winblad,
2004). The human urine is of particular interest for which contains most of the nutrients and
few disease-producing organisms but makes up less than one percent of the total volume in
domestic wastewater. Urine could be separated in a urine diversion dehydrating toilet (UDDT),
which can then be treated and used as fertilizer (Katukiza, A.Y., et al., 2012)
The aim of the present study was to optimize the recovery nutrients from concentrated urine
by air dried soil absorption and ensure minimize ammonia losses in the process. We will also
evaluate the nutritional value of the final soil products and discuss the feasibility of its use as
an agricultural fertilizer.
Materials and methods
The urine was collected from the men’s tank of the No Mix system in the office building. During
collection and storage under non-sterile conditions, the urea present in the fresh urine was
hydrolyzed to ammonium due to microbial activity of the system. The soil for the experiment
was excavated from surface 20cm of the ground in the campus and then air-dried outdoor over
2mm sieve to save. Basic phy-chemical properties of the stored urine and the original soil are
shown in Table 1.
During the first process step, in order to ensure the ammonia volatilization less enough and
acid consumption minimum as well, stored urine which adjusted pH to 6,5,4,3 and 2 with
12mol/L hydrochloric acid were concentrated to one-tenth of the original volume and collected
the condensate water in lab-scale distillation apparatus, respectively. In the second process
step, we alternately dried and milled the mixture of concentrated urine (pH<4) and air-dried soil
particles (d<2mm) whose mass ratio 1:2, and detected the absorption status of nutrients in the
urine on the soil particles, especially about nitrogen.
Table 1 Characteristics of the stored urine and original soil
Parameter
pH
Unite
-
Stored Urine
9.13
Parameter
pH
Unite
-
original soil
8.8
-1
mgNL
-1
6172.16
TKN
mgNg
mgNL
-1
5829.21
Water content
%
Urea
mgNL
-1
314.45
Water-holding capacity
%
Ptot
mgPL
-1
306.03
Ptot
mgP2O5g
Ktot
mgKL
-1
2737.42
Ktot
mgK2Og
TOC
mgCL
-1
5488
TOC
mgCg
Ntot
+
NH4 +NH3
0.3157
1.31
28.5
-1
2.88
-1
20.6
-1
24.9
Results
As a result of comparison of the ammonia volatilization rate under the different pH, it was
clearly found that the optimum pH adjustment range was pH<4, and the volatilization rate less
-3-
than 0.4% (Figure1). With the increase of the mixed times, nutrient concentration in the soil
productions increase gradually. Contrasted with the idea TKN (Hypothesis non- volatile in the
test process) and the actual TKN in the soil productions, the ammonia volatilization rate was
about 10%. After 7 times alternately mixed, dried and milled TKN content in the soil production
could reach 15% (Figure 2). Referred to the standard of complex fertilizer (GB15063-2009) in
China, the total nutrient content (N+P2O5+K2O) in the soil production could up to 25%, which is
feasible to use as an agricultural fertilizer.
Figure 1 Ammonia volatilization rate under pH between 2 to 6 during the concentration process
Figure 2 TKN concentration of the soil during repeated absorption process
Conclusion
In conclusion, it is a practicable method to recover all nutrients from source-separated
human urine and use the production as an agricultural fertilizer by combining concentration
and absorption on soil.
References
Katukiza, A.Y., Ronteltap, M., Niwagaba, C.B., Foppen, J.W.A., Kansiime, F., Lens, P.N.L. (2012)
Sustainable sanitation technology options for urban slums – a review. Biotechnology Advances.
30(2012), 964– 978.
Uno Winblad (Ed.) (2004) Ecological sanitation (second edition). Stockholm Environment Institute,
Stockholm, Sweden.
-4-
Investigation into determination method of anti-malarial drugs
in agricultural soil assumed as human urine reuse
1
1
2
Hideaki. MIYAI* , Nowaki. HIJIKATA , Takashi. KAKIMOTO , Naoyuki. FUNAMIZU
1
2
1
Department of Environmental Engineering, Hokkaido University
Department of Water Environment, Center for Environmental Science in Saitama
Keywords: urine reuse; anti-malarial drugs; agricultural soil; determination method; LC/MS
Although diffusion of appropriate sanitation is one of the big issue in Millenium development
goals, one speculation indicates the difficulty in sub-Sahel region in Africa. For this region, it
has been expected to introduce an on-site wastewater differentiable treatment system, since
the system has advantage for sewer pipe free, water free and recovery of fertilizer
components. Several attempts have shown that human urine obtained from the system is
available to crops and vegetables as a liquid fertilizer. On the other hands, pharmaceuticals
contained in the urine might be widely spread in environment when urine is directly reused.
Assumed as urine reuse in sub-Sahel region, behaviors of anti-malarial drugs, which are
commonly distributed in the region, in agricultural field should be monitored. However,
determination method of anti-malarial drugs in soil has not been developed, so far. In this
study, therefore, the determination method using LC/MS and solid phase extraction (SPE)
were investigated.
Four anti-malarial drugs, chloroquine (CQ), doxycycline (DX), quinine (Q) and artesunate
(AS), were focused in this study, since they are highly excreted in urine as unchanged form or
commonly distributed in sub-Sahel region. As extract solution from soil, water, methanol and
methanol +KCl were compared in the present study. 0.03 mg of anti-malarial drugs were
spiked in 10 g of soil mixture (river sand and compost at the ratio of 4:1) and extracted with 30
mL of extract solution by shaking and sonication. The suspension was centrifuged and the
supernatant was collected. These procedures were done again. The collected supernatants
were filtered through glass filter and set up at 90 ml. Then 30 ml of them were transported in
2000 mL of pure water adjusted pH 2.00±0.05 with HCl. The liquid was load in conditioned
SPE cartridge (Oasis HLB, 6 cc/ 500 mg) and washed with 5 mL of pure water. Target
compounds in the cartridge were eluted with 5 ml of acetonitrile and 5 ml of mixture of
acetonitrile and pure water (1:1). The eluate was filtered and injected into LC/MS system.
Separations of the targets were done on a SunFire C18 (2.1 × 50 mm, 3 mm) column with 10
mM ammonium formate in ultrapure water containing 0.3% formic acid and acetonitrile by
gradient program.
Recovery rate of targets in methanol and methanol +KCl extraction were relatively higher than
water extraction. The values of CQ, DX, Q and AS in methanol +KCl extraction were 16±1.3%,
65±2.7%, 80±5.1% and 88±2.7%, respectively, and those in methanol extraction were 9±0.1%,
50±6.3%, 59±0.9% and 90±2.2%, respectively. Recovery rate of CQ, DX and Q in methanol
+KCl extraction were significantly higher than that of methanol (t-test, p < 0.05). One reason
of high recovery of DX and Q in methanol +KCl extraction might be amide radical, since
positive charge of the amide radical would ionically bound with soil. On the other hands,
recovery of CQ, which is high log Kow, was not success in the present study. Therefore,
extraction with hydrophobic solvent (e.g. acetone, dichloromethane) should be further
investigated.
-5-
-6-
Detection, Quantification and Isolation of Escherichia coli
O157 with Flow Cytometry and Fluorescence-Activated Cell
Sorting
S. Ozawa#*, S. Ishii*, S. Okabe*
* Division of Environmental Engineering, Faculty of Engineering, Hokkaido university
(〒060-8628 North 13, West 8, Kitaku, Sapporo, Hokkaido, Japan)
Keywords: E. coli O157; Flow cytometry; Fluorescence-activated cell sorting
Several disease incidents have occurred directly or indirectly by drinking water, river water, or
recreational water polluted by pathogens. In recent years, enteric diseases caused by the use
of polluted irrigation water were reported. Pathogenic bacteria in irrigation water may
contaminate vegetables and can cause foodborne diseases. Microbiological safety is also
necessary to be verified for reclaimed water that has been used increasingly over the world.
Flow cytometry (FCM) and fluorescence-activated cell-sorting (FACS) have been developed
as strong tools for detecting, quantifying and recovering microorganisms from aquatic
environments. However, it is still challenging to isolate rare pathogens from environmental
samples without pre-incubation.
Particles in FCM individually flow along laminar sheath fluid. Each particle is irradiated with
laser beams, and resulting signals (forward scatter, side scatter, and various fluorescent
signals) are monitored. When FCM-FACS is used, particles with specific characteristics are
electrically charged, and can be individually sorted by their charge.
FCM-FACS has several advantages in environmental microbiology. The use of fluorescentlylabeled antibodies or fluorescent probes enables to detect microorganisms specifically from
complex populations. FCM can detect thousands of particles in a second and sort
immediately, therefore high throughput assay is available. Cells can be isolated directly from
water samples prior to incubation in a medium and bacterial population diversity is preserved.
The objective of my study is to develop a method to detect, quantify and isolate rare
pathogens from environmental water by using FCM-FACS for estimating contamination
source contribution.
Optimizing fundamental method by using pure culture samples were implemented. As a result,
sufficient amount of antibody was verified. Sorting efficiency from K12 and O157 mixed
culture sample (Figure 1) was verified by quantitative PCR (Figure 2, Figure 3).
As a future plan, sorting efficiency especially single-cell sorting should be improved. To
develop and optimize the method to recover live bacteria from environmental water, several
methods reported for aquatic samples and soil samples will be applied.
M6
M5
M4
Figure 1 Detection of O157 from K12-O157 mixed cultures by FCM. Samples with different K12/O157
ratio were stained with APC-labeled antibody and FITC-labeled antibody. Horizontal axis means
fluorescence from FITC and vertical axis means one of APC. Particles in R2 gate were sorted. M6
contains 52.8%, M5 contains 9.2% and M4 contains 1.1% of O157.
-7-
M6
77.6%
M5
55.1%
M4
33.2%
Figure 2 Detection rate (i.e. detected O157 cell numbers by qPCR divided by sorted O157 cell
numbers) from different ratio of K12 and O157 mixed sample in Figure1. Detection rate was converted
based on regression line of colonial PCR (Figure 3). The data over 100% after conversion was
considered as 100%. Error bar shows difference between results of duplicated wells.
Figure 3 qPCR result of O157 added as control. Horizontal axis shows Log10 O157 cell numbers added
as control and vertical axis shows Log10 O157 cell numbers detected by qPCR. Detection rate (i.e.
detected O157 cell numbers divided by added O157 cell numbers) were 37.8 % in average
References
Tani, K. and Nasu, M. (1999) Escherichia coli O157 in Natural River Water, Microbes and Environments.
14(2), 101-105
Centers for Disease Control and Prevention. (2006) Update on Multi-State Outbreak of E. coli O157:H7
Infections From Fresh Spinach, October 6
Biegala, I., & Not, F. (2003). Assessment of picoeukaryotes in the natural environment by using taxonspecific oligonucleotide probes in association with tyramide signal amplification-fluorescence.
Applied and Environmental Microbiology, 69(9), 5519.
Tanaka, Y., Yamaguchi, N., & Nasu, M. (2000). Viability of Escherichia coli O157:H7 in natural river
water determined by the use of flow cytometry. Journal of Microbiological Methods, 228–236.
Picot, J., Guerin, C. L., Le Van Kim, C., & Boulanger, C. M. (2012). Flow cytometry: retrospective,
fundamentals and recent instrumentation. Cytotechnology, 64(2), 109–30.
Ferrari, B. C., Winsley, T. J., Bergquist, P. L., & Dorst, J. V. (2012). Flow Cytometry in Environmental
Microbiology: A Rapid Approach for the Isolation of Single Cells for Advanced Molecular Biology
Analysis. Methods in Molecular Biology, 881, 3–26.
-8-
Comparison of strain culture and real-time PCR for
identification of Escherichia coli in environmental water
#
J H Zhou*, X C Wang *, Z Ji*, L M Xu*, Z Z Yu*
* Key Lab of Northwest Water Resource, Environment and Ecology, MOE, Xi’an University of
Architecture and Technology, Xi’an 710055, P.R. China
#
Corresponding author, E-mail: [email protected]
Keywords: culture method; real-time PCR; Escherichia coli
This study compared a membrane filtration method on MFC agar/culture method and a realtime PCR method to detect Escherichia coli (E. coli) in environmental water. Real-time PCR
detection method is incapable of distinguishing between viable and non-viable
pathogenic microorganisms while culture method can detect the viable cells. And the
influent of Siyuan sewage system and the effluent of MBR were collected to prepare
experiment water samples. The E. coli was spiked into water samples as bacterial tracer. The
concentration of E. coli was detected both by culture method and real-time PCR.
We used 7 concentration gradient of recombinant plasmid as template proceeding real-time
PCR, then we could get the standard curve as shown Figure 1.1. The result indicated that
0
6
2
good linear relation was between 10 and 10 copies/µL and R was around 0.993. The
detection limit was less than 5 copies/µL.
As a result of comparison of the different water samples, we can conclude that different water
quality has different influences on recovery rate. The recovery rate of high turbidity of water
was 37.3% while that of low turbidity was 63.9% during the protocol of real-time PCR
detection.
The water samples obtained from the MBR effluent was treated with different pore size
membranes and the results were shown in Figure 1.2. It was found that the differences of the
E. coli concentration between two methods were found obviously variation with 0.22 µm
membranes, whereas the variations were relatively slight when the samples passed through
0.45 µm and 0.65 µm membranes, respectively. We can conclude that different treatments
have different influences on the detection of E. coli by two methods. Comparing the result of
three parallel tests, the variation of culture method was smaller than that of real-time PCR.
The concentration of coagulant added into water samples also had influences on E. coli
removal efficiencies and the consequence we could infer from Figure 1.3. It was clear that the
removal efficiencies were increased with the increase of concentration of coagulant. The
concentration of E. coli measured by culture method was ten times higher than that of realtime PCR.
Figure 1.1 Standard curve of real-time PCR
-9-
Concentration (copies/L)
1.E+06
MFC-Culture
Real-time PCR
1.E+05
1.E+04
1.E+03
1.E+02
0.22 μm
(a)
1.E+06
MFC-Culture
Real-time PCR
1.E+05
1.E+04
1.E+03
1.E+06
1.E+02
MFC-Culture
Real-time PCR
1.E+05
1.E+04
1.E+03
1.E+02
0.45 μm
0.65 μm
(b)
(c)
Figure 1.2 Concentration of E. coli treated with different pore size of membranes
1.E+06
MFC-Culture
Real-time PCR
1.E+05
1.E+04
1.E+03
1.E+02
2 mg/L
5 mg/L
8 mg/L
10 mg/L
15 mg/L
Figure 1.3 Concentrations of E. coli after using coagulant
References
Ahmed, W., Tucker, J., Bettelheim, K.A., Neller, R. & Katoulia, M. (2007) Detection of virulence genes in
Escherichia coli of an existing metabolic fingerprint database to predict the sources of
pathogenic E. coli in surface waters. Water Res, 41, 3785 – 3791.
Maheux, A. F., Be´Rube´, E., Boudreau, D. K., Cantin, P., Boissinot, M., Bissonnette, L., Rodrigue, L. &
Bergeron, M. G. (2011) Ability of three DNA-based assays to identify presumptive Escherichia
coli colonies isolated from water by the culturebased mFC agar method. Water Res, 45, 26382646.
O’hanlon, K. A., Catarame, T.M.G., Blair, Ian. S., Mcdowell, D. A. & Duffy, G. (2005) Comparison of a
real-time PCR and an IMS/culture method to detect Escherichia coli O26 and O111 in minced
beef in the Republic of Ireland. Food Microbiol, 22, 553–560.
Toze, Simon (1999). PCR and the detection of microbial pathogens in water and wastewater. Water Res,
33, 3545-3556.
-10-
Bacterial Extracellular Polymeric Substances as a Novel
Adsorbent for Human Noroviruses
T. Yoshimura#*, D. Sano*, A. Suenaga*, T. Miura*, S. Okabe*
*Division of Environmental Engineering, Faculty of Engineering, Hokkaido university
(〒060-8628 North 13, West 8, Kitaku, Sapporo, Hokkaido, Japan)
Keywords: human noroviruses, enteric bacteria, extracellular polymeric substances
Human norovirus is one of the leading causes of infectious gastroenteritis worldwide, and it
has been estimated that up to 200,000 deaths of children are caused by noroviruses in
developing countries. For the sake of preventing the infection caused by norovirus, it must be
effective to reveal the lifecycle of norovirus and to shut the infectious route of noroviruses.
However, the actual infectious ruotes of noroviruses in human society including water
environments have remained to be elucidated.
In this study, we paid attentions to the two scientific facts concerning noroviruses and some
bacteria and hypothesized that some human enteric bacteria can specifically capture human
norovirus particles. One scientific fact as the key of this study is an interesting characteristic
about the way of norovirus infection. Some recent studies showed that histo-blood group
antigens (HBGAs) are exploited by human norovirus as cellular receptors in the infection to
human gut epithelial cells. Another important scientific fact is about the characteristic of the
substances existing on the surface of some bacteria. It has been proved that some human
enteric bacteria have similar structure to human HBGAs on their outer surface.
Based on these scientific facts, we hypothesized that human noroviruses recognize bacterial
HBGA-like substances as well as human HBGA. If this hypothesis is correct, there is a
possibility that norovirus bounded to those HBGA-positive bacteria can be protected from the
external stimuli, including disinfection in water treatment processes and sunlight radiation. In
order to elucidate these hypotheses, it is necessary to clarify the binding characteristic of
noroviruses to those HBGA-positive bacteria.
In our laboratory, human enteric bacteria which contain larger amount of HBGAs were
isolated. The binding between the strain registered as Enterobacter sp. SENG-6 and
norovirus-like particles (NoVLPs) were confirmed by transmission electron microscopy (TEM)
(Figure 1), in which NoVLPs were observed mainly in their capsular region.
Based on this result, extracellular polymeric substances (EPS), consisting of the capsular,
was extracted from this strain and two other strains (Escherichia coli K12 and Staphylococcus
epidermidis ATCC 35984), and HBGA-like substances which bound to NoVLPs were detected
by enzyme-linked immunosorbent assay (ELISA). As a result, blood group A antigen-like
substances were detected from EPS (Figure 2), and it can be said that human norovirus may
recognize the A-like substances included in bacterial EPS by the same way as the recognition
of human HBGA as their binding site.
The binding affinity between NoVLP and EPS was confirmed by quartz crystal microbalance
(QCM). The significant affinity was observed in the binding between NoVLP GII.6 and EPS
from Enterobacter sp. SENG-6. The binding constant was estimated to be larger than 3.1 x
6
-1
10 [M ] when Langmuir type binding is assumed. This value was quite similar to that of
6
9
antigen-antibody reaction (10 -10 ), so it seemed that the binding between norovirus and the
EPS can be significant even in water environments.
-11-
NoVLP GII.6
Figure 1 TEM image of the binding between NoVLP GII.6 and Enterobacter sp. SENG-6 (x 20,000).
4
A-like substances
B-like substances
Relative absorbance
O(H)-like substances
3
2
1
0
Enterobacter sp.
SENG-6
E.coli K12
S. epidermidis
ATCC 35984
Figure 2 ELISA for the binding of HBGA-like substances in EPS from each strain of bacteria with GII.
6 NoVLP.
References
Ming et al. 2005. Norovirus and its histo-blood group antigen receptors: an answer to a historical puzzle.
Trends Microbiol. 13: 285-293
Nasir et al. 2009. A study of norovirus-HBGA interactions. Chalmers University of technology, University
of Gothenburg.
Springer et al. 1961. Blood Group Activity Of Gram-Negative Bacteria. J. Exp. Med. 113: 1077-1092
Huang et al. 2003. Norovirus Bind to Human ABO, Lewis, and Secretor Histo-Blood Group Antigens:
Identification of 4 District Strain-Specific Patterns. The Journal of Infectious Disease. 188: 19-31
-12-
Comparison of bioassays using algae and luminescent
bacteria for ecotoxicity assessment of reclaimed water
#
Maoni Wu, Xiaochang Wang , Xiaoyan Ma
#
Keywords: Chlorella vulgaris; Ecotoxicity; Reclaimed water system
Generally speaking, water recycling is that wastwater was treated to achieve the
standard of reuse. The standard must meet health, people sensory,equpment
structure demands.However, the standard excluded ecotoxicity of reclaimed
water.What’s more, ecotoxicity of residual trace toxic substances in reclaimed water is
unknow.So in this paper, in order to evaluate ecotoxicity of reclaimed water,a
reclaimed water recycle system was set up in a campus.
In the reclaimed water recycle system,three lakes and a wasterwater treatment
2
with an A O biological unit and a MBR were set up. The influent of wasterwater treatment
was a mixture f black water from toilet flushing, grey water from miscellaneous uses,and
kitchen wastewater from the university anteens. The effluent from the MBR was suppied to
three lakes which played both the functions of landscaping and storage reservoirs where the
water was further supplied to buildings for toilet flushing and to the green belt for gardening
and irrigation. In the research, ecotoxicity of MBR effluent and three lakes were detected.
Inhibition test with alga growth was the important method to detect ecotoxicity in research.
Ecotoxicity of four reclaimed water were detected using Chlorella vulgaris, which reflects the
changes of ecotoxicity in reclaimed water recycle system, and compared with luminescent
bacteria test.
Figure 1 the relationship between standard substances with inhibition according to Chlorella vulgaris
test
100
60
40
20
0
60
40
20
-20
0
0
100
200
300
400
100
1
2
60
40
20
0
0.1
0.2
0.3
Concentration of Cu (mg/L)
0.4
20
0
0.1
0.2
0.3
0.4
0.5
Concentration of Ni (mg/L)
100
y = 550.2x + 37.69
R² = 0.838
60
40
20
0
0
40
Concentration of Zn (mg/L)
Inhibition(%)
Inhibition(%)
80
y = 188.3x + 30.25
R² = 0.996
60
3
80
y = 319.7x + 3.900
R² = 0.992
80
0
0
Concentration of Phenol (mg/L)
Inhibition(%)
100
y = 18.56ln(x) + 63.2
R² = 0.986
80
Inhibition(%)
y = 0.255x - 0.803
R² = 0.997
80
Inhibition(%)
Inhibition(%)
100
80
y = 275.6x + 39.03
R² = 0.891
60
40
20
0
0
0.02
0.04
0.06
Concentration of Cr(mg/L)
0
0.1
0.2
0.3
Concentration of Cd (mg/L)
Six standard substances was deteceted with Chlorella vulgarris, which included Phenol,
Zn (ZnSou4. 7H2O), Ni (NiCl2. 2H2O), Cu (CuSou4), Cr (K2Cr2O7), Cd (CdCl2). In fig.1, there is
2+
an index relationship between Zn and inhibition and other have a good linear relationship
with inhibition.
-13-
Table 1 Standard substances detection with Chlorella vulgaris and Q67
Zn
2+
Cu
2+
Cd
2+
Cr
6+
2+
Ni
Substances
Phenol
1227 EC50(mg/L)
199
0.49
0.14
0.04
0.02
0.10
Q67 EC50(mg/L)
222
0.80
2.74
0.40
2.71
-----
1227- Chlorella vulgaris ; Q67-Vibrio-qinghaiens
Table2 The comparison between inhibition test with Chlorella vulgaris and bacterial test with Q67
Quantity
5
2.0×10 L/ d
5
2.0×10 L/d
0L/d
0L/d
Weather
EC50(Times)
MBR
H1
H2
H3
1227
13.53
8.89
7.12
—
Q67
13.75
10.47
13.1
7.56
1227
10.86
5.04
5.05
4.04
Q67
—
—
—
—
1227
7.72
4.95
4.62
3.67
Q67
10.75
—
—
17.54
1227
12.22
9.92
5.4
6.21
Q67
12.26
7.14
23.39
13.86
Rainy
Sunny
Sunny
Sunny
1227- Chlorella vulgaris ; Q67-Vibrio-qinghaiensis; —Stimulate growth ; H1: lake 1; H2: lake 2;
H3: lake 3； Quantity: Quantity of water intake to lakes
The result shown that reclaimed water without concentration had no ecotoxicity, but
concentrated water by revise osmosis has inhibition to the growth of chlorella vulgaris; MBR
effluent in the reclaimed water recycle system was good stability and lowest ecotoxicity;
among three lakes, the largest influence from the weather was lake 3, and ecotoxicity of lake
3 was highest. Algae test with chlorella vulgaris is much sensitive than luminescent bacteria
test with Q67 by detecting standard substances and reclaimed water in reclaimed water
recycle system.
References
State Environmental Protection Administration, Detection of water and wastewater analysis, Fourth Ed.,
China Environmental Science Press, Beijing, 2002 (in Chinese).
OECD guidelines for the testing of chemicals, freshwater alga and cyanobacteria, growth inhibition test,
2006.
Lin J. H., Kao W. C., Tsai K. P., Chen C. Y.(2005), A novel algal toxicity testing technique for assessing
the toxicity of both metallic and organic toxicants, Water Res., 39, 1869-1877.
Liu Q., Zhang X.F., Li T.W., Su X.R.(2006), Effects of light on growth rate, chlorophyll level and cell
cycle in four alga species, Journal of Da Lian fisheries university. 21(1), 24-30.
Jayne F. R., Roger V. E., Oliver R. P. Toxicity of haloacetic acids to freshwater algae. Ecotoxicol.
Environ. Saf.73 (2010) 56–61
-14-
Isolation and characterization of membrane fouling
substances from a membrane bioreactor
#
Y.S. Hu*, X.C. Wang *, Y.M. Zhang*, Y.Y. Li**, H. Chen*, P.K. Jin*
*Key Lab of Northwest Water Resource, Environment and Ecology, MOE, Xi’an University of Architecture
and Technology, Xi’an 710055, P.R. China
** Graduate School of Environmental Studies, Tohoku University, 6-6-06 Aza-Aoba, Aramaki, Aoba-ku,
Sendai, Miyagi 980-8579, Japan
*Corresponding author, E-mail: [email protected]
Keywords: A-A-O-MBR process; Extracellular polymeric substances; membrane fouling
Membrane fouling is one of the barriers for MBR application which not only influences
effluent quality, but also increases operation cost. However, it is a complex process and
caused by many factors. EPS are the main foulants which make up of many other substances
such as protein and polysaccharides, so it is representative and meaningful to study EPS.
What’s more, EPS are produced and can also be utilized by microorganisms, which may
contribute to membrane fouling control by providing proper conditions.
To understand the membrane foulants (EPS in this study) and their characters, a full scale
anaerobic-anoxic-oxic (A-A-O) biological unit followed by a submerged MBR for reclaimed
2
water production was studied. Under a constant flux of 16L/m h, TMP varied narrowly between
12 and 22 kPa in 9-month duration with only enhanced flux maintenance (EFM) operation and
high effluent quality.
Extracellular Polymeric Substances (EPS) in liquids at different steps was isolated and
analyzed, it was found that both protein and polysaccharide concentrations decreased along
the A-A-O-MBR train, and there was no apparent EPS accumulation as time elapsed, which
indicate that microorganisms can produce and utilize EPS.
To analysis the change of foulants in sludge, the variation tendencies of humic-like
substances and protein in SEPS were demonstrated by Fluorescent excitation-emission matrix
(EEM) and the results showed that these substances did not seem to accumulate on/in the
membrane and caused obvious membrane fouling. And the protein can be utilized in
anaerobic or anoxic conditions, and produced in aerobic conditions, and can be completely
separated by membrane which causes the membrane fouling. While humic-like substances
change a little and can be consumed in a very limited scale.
To understand the foulants on membrane, SEM was used to observe the membrane, it was
found that a thin cake attaches on membrane and cannot be removed by routine aeration,
while this fouling cake may contribute to avoid membrane fouling. Fourier transform infrared
spectroscopy (FTIR) was used to analyze this fouling cake and demonstrated that proteins,
polysaccharides, humic acid and other substance with hydroxyl and amino groups are the
main foulants.
As a kind of main membrane foulants, EPS in solution and sludge have different behaviors,
because, in solution, the concentrations decrease along the system, while in sludge, they
change with the conditions. Microorganic activities have an important impact on EPS
production and consumption. So to control membrane fouling, proper conditions and operation
are very important.
-15-
1000
400
B
300
A
220
220
300
400
500
Em. Wavelength [nm]
550
450
(b)
Ex. Wavelength [nm]
450
(a)
Ex. Wavelength [nm]
Ex. Wavelength [nm]
450
400
B
300
A
220
220
300
400
500
Em. Wavelength [nm]
(c)
400
B
300
A
220
220
550
300
400
500
Em. Wavelength [nm]
550
-100
1000
(d)
B
300
220
220
A
300
400
500
Em. Wavelength [nm]
550
400
450
(e)
Ex. Wavelength [nm]
400
450
Ex. Wavelength [nm]
Ex. Wavelength [nm]
450
B
300
220
220
A
300
400
500
Em. Wavelength [nm]
550
400
(f)
B
300
220
220
A
300
400
500
Em. Wavelength [nm]
550
-100
Fig. 1. EEM spectra of influent, SEPS and effluent. (a) Influent; (b) SEPS of anaerobic tank sludge; (c)
SEPS of anoxic tank sludge; (d) SEPS of oxic tank sludge; (e) SEPS of membrane tank sludge; (f)
Effluent.
References
S. Judd, The MBR Book: Principles and Applications of Membrane Bioreactors in Water and Wastewater
Treatment, Elsevier, Oxford, 2006.
Y. Miura, Y. Watanabe, S. Okabe, Membrane fouling in pilot-scale membrane bioreactors (MBRs)
treating municipal wastewater: Impact of biofilm formation, Environ. Sci. Technol. 41 (2) (2007)
632-638.
Z. W. Wang, Z. C. Wu, G. P. Yu, J. F. Liu, Z. Zhou, Relationship between sludge characteristics and
membrane flux determination in submerged membrane bioreactors, J. Membr. Sci. 284 (2006)
87-94.
Z. W. Wang, Z. C. Wu, S. J. Tang, Extracellular polymeric substances (EPS) properties and their effects
on membrane fouling in a submerged membrane bioreactor, Water Res. 43 (2009) 2504-2512.
R. S. Trussell, R. P. Merlo, S. W. Hermanowicz, D. Jenkins, The effect of organic loading on process
performance and membrane fouling in a submerged membrane bioreactor treating municipal
wastewater, Water Res. 40 (2006) 2675-2683
J. P. Crou, M. F. Benedetti, D. Violleau, J. A. Leenheer, Characterization and copper binding of humic
and nonhumic organic matter isolated from the South Platte river: evidence for the presence of
nitrogenous binding site, Environ. Sci. Technol. 37 (2003) 328-336
-16-
Evaluation of Intermittent Sand Filtration for Removal of
Greywater-related Micropollutants: UV Filter Compounds
S. Charchalac#*, K. Ushijima**, N. Hijikata**, N. Funamizu**
* Graduate School of Engineering, Hokkaido University, Japan (e-mail: [email protected])
** Faculty of Engineering, Hokkaido University, Japan
Keywords: greywater reuse; UV filters; intermittent sand filtration
Reuse of used water is recognized as a necessity rather than an option for a large population
worldwide. Decentralized greywater treatment systems have focused on achieving
discharge/reuse levels pertaining to standard organics and nutrients (Revitt et al., 2011),
however, emergent micro-pollutants and other xenobiotic organic compounds –XOCs– will
potentially play an important role in the reuse of wastewater (Hernandez et al., 2011).
Intermittent sand filters –ISFs– equipped with geotextile filters have been evaluated
previously (Charchalac et al., 2011) as a strong alternative to reclaim domestic greywayer
from laundry and shower sources by reducing organics and nutrients to low levels but have
not been evaluated for micropollutants. Researchers have claimed the importance of such
systems as a barrier to remove specific XOCs from reaching environment (Revitt et al., 2011).
UV compounds are among many of the emergent pollutants that might increase in
concentration in greywater effluents; they were designed to protect human skin from solar UV
radiation and to be used in sunscreen products but are increasingly being included in other
personal care products such as shampoos, moisturizing creams, lipsticks and others. Some
of these compounds might have potential effects on crops and agricultural fields. Four organic
UV filter compounds were selected to be evaluated based on type, market use and the
hydrophobic/hydrophilic characteristics (Table 1.1).
Table 1.1 Selected UV Filter Compounds
Type
Compound
CAS No.
MW(g/mol)
LogKow
Max% *
Aminobenzoic acid
4-p-Aminobenzoic acid (PABA)
150-13-0
137.14
0.83
15%
Benzophenones
Benzophenone 3 (BP3)
131-57-7
228.24
3.79
6%
Cinnamate
Ethylexyl methoxycinnamate (OMC)
5466-77-3
290.4
5.8
7.50%
Photostabilizer
Octocrylene (OC)
6197-30-4
361.49
7.35
10%
*Standards form USDA
Six intermittent sand filters were prepared with different configurations regarding depth,
media size and layers (Table 1.2) and operated for 4 continuous months. All the ISFs were
equipped with geotextile (polypropylene nonwoven needle-punched fibers; pore size 0.14
mm) above the sand surface to remove suspended solids.
Table 1.2 Configuration of ISFs Sand Media Layers and Particle Size (d10>)
ISF Column
Depth
0-20 cm
20-40 cm
A
B
C
D
E
F
0.60 mm
0.60 mm
0.60 mm
0.90 mm
0.90 mm
0.60 mm
0.30 mm
0.60 mm
0.60 mm
40-60 cm
0.30 mm
The influent greywater consisted of a 40:60 mixture of laundry and shower effluents
collected from a single person daily use of a selected set of personal care products. Hydraulic
2
loading rate was a daily 16 ml/cm split into three equal discharges (9 AM, 1 PM and 6 PM).
-17-
Parameters (TSS, COD, TP, TN) were measured following standard methods and the
reduction rates in the Intermittent Sand Filters were observed to evaluate biological activity.
UV Filters were determined by solid phase extraction and liquid chromatography coupled with
a mass spectrometer following a method developed to detect them in environmental samples
(Bratkovics et al., 2011). UV filter compounds were all spiked directly from >99% purity
products supplied by chemical companies for a target concentration of 1 ppm in the LLGW.
Figure 1.1 Removal of UV Compounds by ISFs
After spiking UV compounds for an average concentration of 1 ppm in greywayer, only
PABA was recovered in concentrations similar to the expected, the other three compounds
were measured in significant lower concentrations, which resemble the theoretical maximum
dissolved concentration according to the USEPA EPISuite 2011. This means that a part of the
spiked compounds precipitated into a solid due to its hydrophobic nature and was most likely
removed by simple filtration.
Figure 1.2 Removal of UV Compounds by ISFs
Regarding the removal of the dissolved part of the hydrophobic compounds, the
concentration reduced above 91% even in the shallowest ISF-A (20 cm), whereas the
removal of the hydrophilic one (PABA) was noticed to be better with the increase of depth.
Probably the major mechanism is the attachment of the hydrophobic compounds to the sand
surface, however the biodegradation and final fate of these compounds in the sand, as well
as the interactions with surfactants are still unclear. In conclusion, ISFs showed a very good
performance in removing these compounds under the limit of detection in this experiment
(0.01 ppm concentration - 99.99% removal).
References
Bratkovics, S. and Sapozhnikova, Y., (2011) Determination of seven commonly used organic UV filters
in fresh and saline waters by liquid chromatography-tandem mass spectrometry. Analytical Methods.
3, 2943-2950.
Charchalac. S. (2011) Treatment of LLGW by Intermittent Sand Filter and Geotextile Filter. M.Sc. thesis.
Div. Env. Eng. Univ., of Hokkaido, Japan.
Hernandez, L., Vieno, N., Temmink, H., Zeeman, G., and Buisman, C. (2010) Occurrence of Xenobiotics
in Gray Water and Removal in Three Biological Systems. Env. Sci. Tech. 44, 6835-6842.
Revitt, D., Eriksson, E., and Donner, E. (2011) The implications of household greywater treatment and
reuse for municipal wastewater flows and micropollutant loads. Water Research. 45, 1549-1560.
-18-
Comparative study of constructed wetlands of various types
for treating polluted river water
1
#1
1
1
Y.C. Zheng , X. C. Wang , J.Q. Xiong , Y.J. Liu , Y.Q. Zhao
2
1
2
School of Civil, Structural and Environmental Engineering, University College Dublin, Belfield, Dublin 4,
Ireland
#
Keywords: Comparative study; constructed wetland; polluted river water
Abstract
With intensive urbanization and rapid industrialization in recent decades, surface water
pollution has become a series issue in China. Therefore, finding appropriate ways for
improving urban river water quality is highly desirable in many cities. Due to their low cost,
simple operation and maintenance, and favorable appearance, constructed wetlands (CWs)
are considered to be a very promising technology for various wastewater treatments. The CWs
can be constructed in different types such as free water surface (FWS), horizontal subsurface
flow (HSSF), and vertical flow (VF) wetlands. In fact, each type of the CWs has its own
advantage and disadvantage. Furthermore, the design and operation of the CWs have to deal
with circumstances much different from the others wastewater treatment plants. In this study,
pilot CWs with different combinations of surface- and subsurface-flow stages were constructed
and operated for treating the polluted river water in a northwestern megacity in China. The
objectives of the study were to compare the performances of different CW systems and to
recommend the most appropriate system for the design and construction of the full scale CWs
for treating the polluted stream water.
Fig. 1 Photos of the pilot CWs and the flow diagram
Five pilot CWs were constructed in the flood land near the confluence of the urban stream
to the main river channel. Each CW system has similar substrates and similar plants but
different configurations with combination of surface- and subsurface-flow stages as shown in
3
Fig. 1. The total flow of the five CW systems was 350 m /d on average which corresponded to
3
2
an average HRT of 3.72 d and an average surface loading of 0.051 m /m ∙d. The construction
of the pilot CWs was completed in August 2010. After 3 months trial operation, they were turn
to continuous operation. In the period from November 2010 to October 2011, water samples
were collected weekly from the influent, effluent, and water at the outlet of each stage of these
CWs. After sampling, the samples were sent to the laboratory and chemical analyses were
conducted within 24 h regarding suspended solids (SS), organic contents (COD and BOD5),
-19-
different forms of nitrogen (TN, NH3-N, NO3-N and NO2-N) and total phosphorus (TP).
Standard methods were referred for the chemical analyses (APHA, 1998). The annual average
concentrations of SS, COD, BOD, NH3-N, TN and TP were 280.0 mg/L, 325.4mg/L, 104.7
mg/L, 29.9mg/L, 39.6 mg/L and 3.9 mg/L, respectively, indicating a very seriously polluted
condition of the river water.
During a one-year operation of the five CW systems, though differed each other in the
combination of VF, HSSF, and FWS stages, average HRT and surface loading, they did not
show much differences in the removals of SS (about 90%), COD (about 70%) and BOD (about
93%). The suspended COD and BOD5 removal was closely related to the suspended solids
removal. It seems clear that the aerobic/anoxic states would be a key factor governing
nitrification and denitrification. The scheme of pure subsurface-flow seems not to be
advantageous for treating the polluted stream water from the viewpoint of nitrogen removal
due to its relatively high surface loading which restricted a provision of sufficient DO for
nitrification as the important first step for nitrogen removal, nevertheless the shortage of DO
seems to be favorable for denitrification. The pure surface-flow CWs in this study could
perform nitrification and denitrification well because through the free water surface oxygen
would be transferred to the upper substrate layer to form an aerobic zone while the bottom
substrate layer could be with low DO concentration so as to form an anoxic or anaerobic zone.
TP removal increased as the surface loading decreased, this indicates that chemical
precipitation under the action of hydroxides might play the main role. As in the case of
sedimentation, surface loading would be an important parameter affecting the process of
precipitation. The SS removal tended to be much less temperature dependent than the other
pollutants while the influence of water temperature was very strong for the removal of NH3-N
and followed by the removals of COD, TN, and TP. The influence of water temperature on the
removal of BOD was not as stronger as the formers, possibly due to the good treatability of the
biodegradable organic matter in the stream water.
Through the one-year study of the five pilot CW systems with different combination of
surface- and subsurface-low stages, it was verified that SS, organic substances, nitrogen and
phosphorus could be effectively removed from the polluted urban stream water by CWs
constructed on the flood land near the confluence of the stream to the large river. As the
polluted urban stream water contains large quantity of suspended substances, there is always
a fear of clogging of the substrate bed. Comparing with subsurface-flow CWs, the surface-flow
CWs are more advantageous for preventing bed clogging and more suitable to be placed in
the first stage in a hybrid CW system. A surface-flow followed by a subsurface-flow CWs
system would be a suitable option for treating the highly polluted river water.
References
APHA (1998), Standard Methods for the Examination of Water and Wastewater, twentieth edition.
American Public Health Association / American Water Works Association / Water Environment
Federation, Washington DC, USA.
Bu, H.M., Tan, X.A., Li, S.Y., Zhang, Q.F. (2010). Temporal and spatial variations of water quality in the
Jinshui River of the South Qinling Mts., China. Ecotoxicology and Environmental Safety 73,
907–913.
Faulkner, S.P., Richardson, C.J. (1989). Physical and chemical characteristics of freshwater wetland
soils. In: Hammer, D.A. (Ed.), Constructed Wetlands for Wastewater Treatment, Municipal, Industrial
and Agricultural. Lewis Publishers, Chelsea, MI, pp. 41–72.
Guo, L. (2007). Ecology-Doing battle with the green monster of Taihu Lake. Science, 317 (5842): 1166.
Hammer, D. (1989). Constructed Wetlands for Wastewater Treatment: Municipal. Industrial and
Agricultural. Lewis Publishers.
IWA (2000). Constructed Wetlands for Pollution Control: Processes, Performance, Design and Operation.
IWA Publishing, London, 156 pp.
Kadlec, R.H., Reddy, K.R. (2001). Temperature effects in treatment wetlands. Water Environ. Res. 73 (5),
543–557.
Shutes, R.B.E. (2001). Artificial wetlands and water quality improvement. Environ. Int. 26, 441–447.
-20-
Characteristics of fecal organic decomposition and nitrogen
transformation in an aerobic composting reactor with sawdust
as bulky matrix under two typical temperatures
Q. Li, X.C. Wang *, H.L. Shi, T. Hu
Key lab of Northwest Water Resource, Environment and Ecology, MOE, Xi’an University of Architecture
and Technology, Xi’an, shaanxi Province, 710055, China
Keywords: aerobic composting; nitrogen transformation; microbial communities
Aerobic composting has been recognized as an applicable method for sanitary disposal of
human feces in a bio-toilet system, this treatment transforms organic waste into substances of
safe and stabilized states, thus serving as agriculture fertilizer. Temperature as a key factor for
composting processes affect the composting reaction on microbial activity and population
o
structure. In this study, using sawdust as bulky matrix, under two typical temperatures (35 C
o
and 55 C), the characteristics of fecal organic decomposition, nitrogen transformation and
microbial communities were discussed over two-week aerobic composting. The composing
reactor used in this study is showed in Fig.1.
Air outlet
Agitating blade
Agitator shaft
Composting reactor(30L)
Motor
Air heater with the
temperature controller
Water-cooling
device
Bottom diffuser
Exhausted air
Flow meter
(1m3/h)
Air pump
Sodium hydroxide
solution
Sulfuric acid
solution
Fig.1 Diagram of the experimental composting reactor
Taking COD content as the indicator of the fecal organic matter, the result showed that
thermophilic composting could speed up hydrolysis process which partly converted nonsoluble
degradable organic matter into soluble substances lead to the soluble COD concentration
increasing quickly at the initial stage, and the total removal was higher in the first 4 days than
that under mesophilic condition.
The main way of total nitrogen (TN) loss was organic nitrogen (Norg) ammonification and
o
ammonia emission. The mesophilic condition of temperature at 35±2 C was beneficial for
ammonifying bacteria growing, and organic nitrogen could be converted into ammonium
effectively under the action of ammonifying bacteria. Therefore, the sufficient increase of
ammonium (NH4-N) concentration could be observed due to the conversion from Norg. TN loss
-1
-1
-1
was 12.71 g·kg (9.74g·kg of Norg, 3.23g·kg of NH4-N), it balanced the amount of ammonia
release (11.65 g/kg). Under thermophilic condition, ammonification processes were inhibited
-21-
due to the high temperature, more organic nitrogen could not be converted into ammonium,
-1
and still retained in the compost, the final TN loss was 5.66 g·kg mainly contributed by
-1
ammonia emission (4.76 g·kg ). Therefore, thermophilic composting was beneficial for
nitrogen retaining.
During composting process, pH was an important factor on nitrogen loss. In mesophilic
composting, pH decreased at the first 2 days due to the formation of low molecular weight fatty
acids with organic matter degradation, while increased quickly with organic acids
+
decomposition and NH4-N formation. With the pH increasing, the equilibrium (NH4 + OH →
NH3 + H2O ) shift towards right and the NH3(g) quickly released in mesophilic composting.
Under thermophilic condition, there was no sufficient pH increasing in the composting process
may due to the inhibited ammonification process in which Norg could be converted into NH4-N.
The NH3 (g) emission was also affected by pH which was still below 7 in composting process.
The diversity of microbial communities increased under both two temperatures, but the
succession processes were different. The typical fecal pathogens such as Coprococcus,
Escherichia and Enterococcus in initial compost died out in the composting process under both
two conditions due to the high temperature and aerobic environment. The development of
microflora in mesophilic and thermophilic composting may contribute to the difference in
organic matter degradation.
References
Bai, F., Wang X.C., 2010. Nitrogen-retaining property of compost in an aerobic thermophilic composting
reactor for the sanitary disposal of human feces. Frontiers of Environmental Science and
Engineering in China.4(2), 228- 234.
Lopez Zavala, M.A., Funamizu, N., Takakuwa, T., 2004. Temperature effect on aerobic biodegradation of
feces using. Water Research. 38, 2406- 2416.
Maeda, K., Hanajima, D., Morioka, R., Osada, T., 2010. Characterization and spatial distribution of
bacterial communities within passively aerated cattle manure composting piles. Bioresource
Technology. 101, 9631- 9637.
Stentiford, E.T., 1996. Composting control: principles and practice. The Science of Composting.
Chapman Hall, 49- 59.
Vitousek, P.M., Aber, J.D, Howarth, R.W., Likens, G.E., Matson, P.A., Schindler, D.W., Schlesinger, H.W.,
Tilman, D.G., 1997. Human alteration of the global nitrogen cycle: sources and consequences. Ecological
Application. 7(3), 737- 750.
-22-
Investigation on maturing period of compost from composting
toilet
#
Natsuru YAMAUCHI* , Nowaki HIJIKATA*, Ken USHIJIMA*, Naoyuki FUNAMIZU*
* Department of Environmental Engineering, Hokkaido University
# [email protected]
Keywords: composting toilet: Ammonia nitrogen: germination index
Composting toilet, which can decompose human excrete with matrix in the reactor, has been
proposed as one solution for sanitation issue in developing country due to advantages for
low-cost and promoting vegetable production (Ushijima et al., 2007, Ushijima et al., 2011,
Ushijima et al., 2012, Hijikata et al., 2011a). To expand the availability of the toilet in all over
the world, several matrixes as an alternative to sawdust is required. It has been suggested
that several agricultural wastes (e.g. rice husk and bio-charcoal) were effective for fecal
decomposition as the matrix (Hijikata et al., 2011b), on the other hands, information about
time required for maturation in each matrixes after setting out from the reactor has been
limited, so far. Differed from normal compost such as animal manure or sewer (Tiquia et al.,
1996, Zhao et al., 2011), compost from composting toilet is produced by unique operation,
since small amount of organic solid such as feces is continuously input in matrix for long time.
+
Therefore, to know its maturing period for safety plant growth, changes of NH4 −N content
and germination index (GI) after composting process were monitored in the present study.
Besides, the difference of maturation progress among several matrixes was investgated.
Sawdust, rice husk and charcoal (made from rice husk) compost were made as continuous
mixing with pig feces (as substitution of human feces) for 53 days. The fecal load ratios of
these composts were finally 3.5 (total input feces / total input matrix). All compost samples
were left in incuvator at 28°C and 50% humidity supposed tropical semi-arid climate. Compost
was sampled at day 0, day 4, day 9, and day 13. All samples were stocked in freezer at -20°C.
Germination test was carried out with compost extraction using Komatsuna (Brassica rapa var.
peruviridis) (Chikae et al., 2006). In germination test, thirty Komatsuna seeds were set on
triplicate filter paper in a petri dish. 8 ml of compost extraction, which was extracted from
compost samples with hot water at the ratio of 1: 20 (w:v), was applied in the petri-dish. The
petri-dish was wrapped with alminum foil and left in incuvator at 23°C. After 24 h, number of
the germinated seeds were counted. After further 96h, root length was recorded. The
germination index (GI) was calculated using the following expression; GI(%) = (% seed
germination ×% root length) / 100. Zucconi et al. (1981) has proposed 50% of GI as an
indicator of phytotoxin-free composts. On the other hands, Tiquia et al. (1996) and Sellami et
al. (2008) have used 80% of GI as an indicator of the disappearance of phytotoxicity and
maturity of compost. In the present study, therefore, we defined that acceptable compost of
GI was 50-80% and best compost of GI was more than 80%.
GI values of charcoal compost reached 81% at day 0. The value of rice husk compost
reached 52% at day 0. The value of sawdust compost was 35% at day 0 and reached 73% at
+
day 4 (Figure 1.1). NH4 −N content of charcoal compost day 0, day 4, day 9 day 13 after
composting procedure were 2.73 mg/g, 1.26 mg/g, 1.35 mg/g and 1.59 mg/g, respectively.
+
NH4 −N content of rice husk compost day 0, day 4, day 9 day 13 after composting procedure
+
were 4.62 mg/g, 4.35 mg/g, 3.62 mg/g and 3.96 mg/g, respectively. NH4 −N content of
sawdust compost day 0, day 4, day 9 day 13 after composting procedure were 6.22 mg/g,
4.37 mg/g, 1.27 mg/g and 0.91 mg/g, respectively (Figure 1.2).
The conclusions resulting from this study are as follows:
(1) Using charcoal for matrix, composting toilet can make best compost without maturation
period.
(2) Using rice husk for matrix, composting toilet can make acceptable compost without
maturation period.
(3) Using sawdust for matrix, 4 days maturation period is required to be acceptable compost.
-23-
GI [%]
NH₄⁺‒ N content [mg/g]
Figure 1.1 Change of germination index (GI) after composting procedure
Days of composting period
(Continuous input feces)
Figure 1.2 Changes of NH4 −N content of compost
+
Days of
maturation period
(No input feces)
References
Chikae M., Ikeda R., Kerman K., Morita Y. and Tamiya E. (2006) Estimation of maturity of compost
from food wastes and agro-residues by multiple regression analysis. Bioresource Technology,97,
1979–1985
Hijikata, N., Yamauchi, N., Ushijima, K. and Funamizu, N. (2011a) Effect of bio-charcoal compost made
by composting toilet for Brassica rapa var. peruviridis growth in pot cultivation Proc. 2nd Ameli-Eaur
International Workshop on Sustainable Water and Sanitation System & 8th International
Symposium on Sustainable Water and Sanitation System Part I, pp.109-114
Hijikata N., Yamauchi N., Yabui K., Ushijima K. and Funamizu N. (2011b) Characterization of several
agricultural wastes as a matrix of composting toilet –from fecal degradation to reuse as a soil
conditioner-. Proc. 8th IWA International Symposium on Waste Management Problems in AgroIndustries, pp.317-324.
Sellami F., Hachicha S., Chtourou M., Medhioub K. and Ammar E. (2008) Maturity assessment of
composted olive mill wastes using UV spectra and humification parameters. Bioresource
Technology, 99, 6900-6907
Tiquia S.M., Tam N.F.Y. and Hodgkiss I.J. (1996) Effect of composting on phytotoxicity of spent pigmanure sawdust litter. Environmental Pollution, 93, 249-256
Ushijima K., Irie M., Sintawardani N., Triastuti J. and Ishikawa T. (2007) Practical model of sustainable
th
sanitation system for urban slum in Bandung. Proc. 5 international Symposuim on Sustainable
Sanitation, 179-188
Ushijima K., Yabui K., Hijikata N., Ito R., Funamizu N. (2011) Development self-buildable simple
composting toilet, Proceedings of IWA aspire (USB-memory), October 2-6, 2011, Tokyo, Japan.
Ushijima K., Hijikata N., Ito R. and Funamizu N. (2012) Effect Estimation of Dry-Toilet Application for
Rural Farmer Family in Burkina Faso. Journal of Arid Land Studies,22(1), in press
Zhao L., Gu W., He P. and Shao L. (2011) Biodegradation potential of bulking agents used in sludge
bio-drying and their contribution to bio-generated heat. Water Research,45, 2322-2330
Zucconi F., Forte M., Monaco A., and Bertoldi M. (1981) Biological evaluation of compost maturity.
Biocycle,7, 27-29
-24-
Anaerobic digestion of food wastes for the production of
carbon source for a membrane bioreactor
Y. M. Zhang, X. C. Wang*, Y.S.Hu
Keywords: anaerobic; food wastes; carbon source
Abstract:
Xi’an Siyuan University is confronted with water shortage because of its location which is on a
hill about 13 km far from the centre city, so there is an anaerobic-anoxic-oxic and membrane
bioreactor combined process which could supply enough reclaimed water for toilet flushing,
gardening, road washing and artificial lake replenishment in all the campus. Now the problem
is that the ratio of COD loading (80mg/L~250mg/L) to TN loading(15mg/L~40mg/L)about the
campus domestic sewage is not enough for better denitrification effect, which could result in
nitrogen accumulation in all the reclaimed water cycle system , also eutrophication may occur
in the artificial lake. All of them request us to add new external carbon source to improve ratio
of COD to TN , finally reduce nitrogen content in the system.
The amount of food wastes in campus dinning hall is more every day. There are a large
number of carbohydrate and protein in food wastes which could produce various easy-to-use
carbon source for biological nutrients removal. So a good idea comes, that is to use food
wastes anaerobic digestion for the production of carbon source for membrane bioreactor.
Food wastes in campus dinning hall have some character. The TS(total solid) and
VS(volatile solid) have not bigger change every day , TS keeps at 15%~20%, VS keeps at
92~98%, VS/TS generally remain fairly constant. The compositon percentage of
carbonaceous organic materials is: carbohydrate (11%~13%), protein (1%~4%), lipid
(2%~3%). The concentration of nutrient is: TCOD (200 g/L ~300 g/L), TN (2000 mg/L~4000
mg/L), TP (300 mg/L~450 mg/L).
The anaerobic fermentation pot is resin material, whose total volume is 12L and valid
volume is 10L. To make the feedstock for experiment, raw food wastes was diluted with tap
water and then shredded with a grinder. The mixing of raw food wastes to tap water is
2:1(w:w). Then inoculating right proportion anaerobic sludge, and control the temperature of
o
reactor at 36 C with water bath, the food wastes anaerobic fermentation begins.
We need a short-term fermentation process for practical application, so about 5 days are
suitable. Experiment shows that when the fermentation time is 5 days, TS and VS haven’t
obvious change; the degradation rate of carbohydrate and protein are respectively 36% and
18%; TCOD and SCOD could increase to a stable status, the ratio of SCOD to TCOD
generally grow to about 0.3; total nitrogen concentration has slight rise and total phosphorus
concentration have slight dropping; ammonia nitrogen concentration have some rise; the
growth rate of latic acid reach to about 4g/L one day; also some volatile fatty acids generate
(mainly acetic acid), but the amount is less than latic acid.
-25-
10mL
10mL
10mL
100mL Measuring
cylinder
100mL Measuring
cylinder
100mL Measuring
cylinder
Magnetic
stirrer
Magnetic
stirrer
Magnetic
stirrer
Figure1 Anaerobic digestion pot and sampling method
In future right proportion carbon sources with the form of fermentation liquid are added to
membrane bioreactor , under the optimal condition controlling, the total nitrogen in A-A-O and
MBR system gets better removal effect.
References
American Public Health Association, 1985. Standards Methods For the Examination of Water and
Wastewater, 16th ed. American Public Health Association, Washington, DC
Charles J. banks; Michael Chessire. Anaerobic digestion of source-segregated domestic waste:
performance assessment by mass and energy balance. Bioresource Technology. 2011,102,612620
Ruihong zhang; Hamed M.el-mashad. Characterization of food wastes as feedstock for anaerobic
digestion. Bioresource Technology 2007, 92, 929-935
-26-
Inactivation mechanism of pathogenic bacteria using lime and
ash in composting toilet
Rui TEZUKA#*, Nowaki HIJIKATA*, Shinobu KAZAMA**,Seyram K. SOSSOU*** Naoyuki
FUNAMIZU*
* Department of Environmental Engineering, Hokkaido University
** Department of Human Environmental Science, Ochanomizu University
*** Department of Teaching and Research in Water Efficiency Management and Sanitation, International
Institute for Water and Environmental Engineering
#:[email protected]
Keywords: composting toilet, high pH condition, inactivation mechanism, pathogenic bacteria
A composting toilet, which can aerobically decompose human excreta using agricultural
waste as matrix, has been proposed as one solution for sanitary issue in developing country,
since the toilet is inexpensive to introduce (Winblad et al., 2004) and can contribute to
agricultural production (Hijikata et al., 2011). On the other hands, compost from the toilet
requires inactivation treatment against pathogenic microorganisms derived from human feces
before agricultural reuse (Sossou et al, 2012). Previous study has shown that high pH
conditons was effective for lethal inactivation of pathogenic bacteria and viruses (Kazama et
al., 2011). However, information about CaO or wood ash requirement per unit compost and
target pH level for inactivation has been still limited.Furthermore, inactivation efficiency and
inactivation pattern in alternative composting matrixes such as rice husk and charcoal has not
been observed. In the present study, therefore, relatioship between applied CaO or wood ash
amount and compost pH was investigated, and then, inactivation rate and damage part of
Esherichia coli, regarded as a model of pathogenic bacteria, in several alkaline level of
compost were observed with three different media.Moreover on the assumption that CaO is
applied when matrix is changec, CaO need was calculated from the viewpoint of risk
assessment.
Compost of rice husk and charcoal were prepared as continuously input of pig feces for 1
month.Alkarine material used were calcium oxide (CaO), regarding as a calcium lime and
commercial wood ash. After adding them to the compost, compost pH was measured after
mixing with pure water at the ratio of 1:20 (w:v). Inactivation rate constant of E. coli
NBRC3301 in three different pH composts, which were about pH 9.5 (without CaO), 10, and
10.5, was also observed in the present study. Adequate CaO or wood ash and 3 g of
autoclaved pig feces were mixed in 50 g of autoclaved charcoal compost, and then 0.3 mL of
incuvated E. coli suspension were inoculated in the compost mixture. 0.3 g of the compost
mixture was appropriately sampled (0-8 h) and E. coli was extracted with 20 mL of 3% (w/v)
beef extract. It was reported that the recoveries of E. coli using this method were 70-100%
4
(Otaki et al., 2002).After adequate dilution (10-10 times), the all extracts were applied in
Trptic Soy Agar (TSA), Desooxycholate Agar (DESO) and Compact Dry EC (C-EC),
respectively. Then, the media were incuvated at 37°C for one day. Followed by a report of
Kazama et al (2011), damage part of E. coli was estimated with inactivation rate constant of
each sampling time on each media. Finally infection risk was assessed on the assumption
that four member family were infected by salmonella used a composting toilet for 3 mounths.
Applied CaO amount and compost pH had liner relation at the range of pH 9-12.To lead the
1 g (dry weight) of compost to pH 10, in the case of charcoal, about 16 mg of CaO was
required and in the case of rice husk, 23 mg of CaO was required.Compared to CaO case,
wood ash slightly incresed the compost pH and this meant larger amount was requred.In the
case of charcoal, 2400 mg of wood ash was required to lead the compost pH to 10.0.
Fig. 1 shows the inactivation rate constant in each three media.In the case of charcoal,
inactivation rate constants in DESO and C-EC media were relatively higher than that of TSA.
This suggested that CaO application caused lethal damage of outer membrane and enzyme
activities in E. coli. Because DESO selects outer membrane with lactose medium and C-EC
selects b-glucuronidase with pepton, pyruvate and lactose medium. In the case of charcoal,
inactivation rate constant in C-EC was higher than those of DESO and TSA. This indicated
-27-
that enzyme activity tended to get lethal damage. As for the wood ash application, tendecy
was similar as the case of CaO. Normarized inactivation rate constant, which was mean value
of inactivation rate constant with three media was increased as the pH increases in both
matrixes and charcoal was more likely to be affected by alkalization. Compared to CaO case,
wood ash was more effecient then CaO at the same pH level.Finally from the viewpoint of risk
assessment, it was found that by 900 mg of CaO and reacting for four hours, it will enable to
-4
decrease the annual infection risk to 10 in both matrixes.
It was concluded that CaO and wood ash application increased the compost pH and
promoted inactivation of pathogenic bacteria to induce damages of outer membrane and
enzyme activities..At the same pH level, wood ash tended to damaged lethally than CaO but
-4
larger amount was requred. Thinking to reduce the infection risk to 10 within 4 hours, about
900 g of CaO was required.
Fig 1. Inactivation rate constant in each three media under several pH conditions (charcoal
and rice husk)
References
Hijikata N., Yamauchi N., Yabui K., Ushijima K., Funamizu N. (2011) Characterization of several
agricultural wastes as a matrix of composting toilet –from fecal degradation to reuse as a soil
conditioner-. Proc. 8th IWA International Symposium on Waste Management Problems in AgroIndustries, 317-324.
Kazama S. and Otaki M. (2011) Mechanism for Inactivation of Bacteria and Viruses in Sawdust Used in
Composting Toilet. Journal of Water and Environment Technology, Vol. 9, No.1, 53 – 66
Otaki M., Nakagawa N. and Ito Y. (2002) The fate of pathogen in composting toilet and risk assessment.
Proc. The 57th Journal of Japan Society and Cicil Engneering Annual conference, Sapporo, Japan,
561-562
Sossou S.K., Ito R., Jibia A., Sou M., Maiga A.H. (2011) Survival od indicator bacteria and helminthes
eggs in composting toilet using sawdust as matrix, Proc. 2nd Ameli-Eaur International Workshop on
Sustainable Water and Sanitation System & 8th International Symposium on Sustainable Water and
Sanitation System Part I, 95-102
Winblad U., Hebert M. S., Calvert P., Morgen P., Rosemarin A., Sawyer R. And Xian J. (2004).
Ecological sanitation revised and enlarged edition. Stockholm Environment Institution, Stochholm
-28-
Design of Resource Recycling Sanitation System Based On
Relationship Between Fertilizer Demand And Potential Supply
Of Human Excreta As Fertilizer In Indonesia
Yosuke Deguchi#*, Ken Ushijima*, Naoyuki Funamizu*
*Department of Environmental Engineering, Graduate school of Engineering Hokkaido University, Japan
Email: [email protected]
Keywords: reuse of human excreta; resource recycling sanitation; Indonesia
Improving sanitary condition of highly populated area in Indonesia is urgent task. Wastewater
effluent from this area contaminates river and it causes bad sanitary condition. Spread of
toilet without treatment facility is cause of this problem. On the other hand, Phosphate are
limited resources. Half of phosphate rock will be consumed until 2060’s. We need to recover
nutrient including phosphate from human excreta in the near future.
Installing composting toilet should become one of the solutions to these problems.
Composting toilet can recover nutrient from human excreta as compost. Many kinds of
technical approach of composting toilet and compost have been tried untill now. Without
consideration of compost usage, composting toilet can not become widespread. Therefore, in
this study, we discussed following resource recycling sanitation system (Figure 1). Feces and
urine are separately treated by composting toilet. Feces are composted. Urine is stored in
plastic tank. Collectors collect compost and urine to collection station. Compost and urine are
brought to farmland by handcart and truck, then used for agriculture at farmland. Each
stakeholder gets compensation for thier work.
When considering driving force of this system, there are three important factors. First point is
linkage netwark design, especially material flow. Second point is benefit flow. Giving
compensation for people involved sanitation system should be keypoint of their participation
to the system. For the above two points, we have to clearify balance of fertilizer demand at
farmland and potential supply of fertilizer produced from human excreta by composting toilet.
In this study, we estimated current balance between fertilizer demand and potential supply
around Bandung city, Indonesia, then drew up fertilizer transportation plan based on case
study. Third point is people’s decision making process. In Indonesia, Muslim is the most
important major group and Islamic context has big effects on people’s decision making
process. Urine and feces are classified “Najis” in Islamic context. Najis is filth and it should be
avoided for pray. When we construct resource recycling sanitation system, we have to fit it to
Islamic sense. However, there are a lot of undefined matters related to Najis (e.g., Useage of
human excreta for agriculture). Therefore, we interviewed three Islamic leaders about Najis
and handling of human excreta in resource recycling sanitation system.
In Bandung city (Kota BDG) and Cimahi city (Kota Cimahi), fertilizer supply exceeds its
demand at farmland. Other areas near Kota BDG , fertilizer supply is less than its demand
(Figure 2). Fertilizer demands in Garut, Subang, and Sumedang are 4.0 to 8.6 times higher
than supplies. They have big potential to accept fertilizer fromother areas. It is one idea that
fertilizer produced in Kota BDG and Cimahi should be transported and consumed to these
areas.
According to results of interviews to Islamic leaders, cocept and each processes of the
sanitation system are basically no problem. Compost produced from human excreta can be
used as fertilizer. When people touch compost and human excreta, washing part of body
contacted by them is enough to clean people for pray. This interview revealed two
considerations. (1) Packing of urine and compost for storage, collection and transportation
should be clean. (2) Compensation to people relating to this system is given for their work and
fertilizer, not for amount of excreta because paying compensation to Najis is prohibited in
Islamic context.
-29-
Figure 1.1 Basic concept of resource recycling sanitation system
Figure 1.2 Fertilizer demand and supply in each area
References
Ingrid Steen. (1998) Phosphorus availability in the 21st century: Management of a non-renewable
resource. Phosphorus and Potassium 17(9/10), 25-31
Ken Ushijima, Mituteru Irie, Neni Sintawardani, Jovita Triastuti and Tadaharu Ishikawa. (2007) Practical
th
Model of sustainable sanitation system for urban slum in Bandung. Proceedings of the 5
international symposium on sustainable sanitation, 179-188
Ken Ushijima, Mituteru Irie, Neni Sintawardani, Jovita Triastuti and Tadaharu Ishikawa. (2007)
Collection system for compost from composting toilet in slum area of Bandung. Environmental
engineering research 44, 505-511
Ken Ushijima, Mituteru Irie, Neni Sintawardani, Jovita Triastuti and Tadaharu Ishikawa. (2006) Field
research on domestic wastewater from the slums in Bandung city. Annual journal of engineering,
JSCE, Vol.50, 1075-1080
-30-
Interface design of composting toilet to actual application to
rural area of Burkina Faso
#
Kenta Yabui* , Ken Ushijima*, Ryusei Ito**, Naoyuki Funamizu*
* Department of Environmental Engineering, Hokkaido University, Japan
**Water, Decontamination, Ecosystem and Health Laboratory, International Institute for Water and
Environmental Engineering (2iE), Burkina Faso
#[email protected]
Keywords: user oriented design, resource recycling sanitation system, composting toilet
Resource recycling sanitation system, which utilize composting toilet, is one of the promising
concept to improve the sanitary conditions in developing countries. Composting toilet makes it
possible for users to reuse human excrement in safe way as fertilizer and users get potential
to increase their income by using this fertilizer to vegetable cultivation. It becomes incentive
for low income farmers. On the other hand, interface design also gives one of important
incentive at actual application. There are few studies on user interface design of composting
toilet, though there are many technological studies on composting toilet.
In this research, we aimed to design composting toilet that people living in rural area of
Burkina Faso willing to choose and use. As a first step, we analyzed design of current toilet
and assumed action in it in detail on 6 families which already committed to install and use
pilot model. Based on these analyses, we determined each detail of design of composting
toilet and toilet room as follows and materialized it.
The reactor itself is rotating to mix the compost. In rural area, it is impossible to use
electricity to mix the reactor, hence, matrix are mixed by only hand power. We assumed 20
Nm as the maximum of acceptable torque for women and children. Although screw mixing
reactor, which is majority of composting toilet, could mix only 12 kg of matrix by 20 Nm,
reactor rotating system could mix 34 kg of matrix.
The width of aisle and entrance of current toilet were 60 ~ 83 cm and 45 ~ 115 cm,
respectively. The size of toilet room was 130 ~ 200 cm long and 130 ~ 180 cm wide. This size
is large enough to set composting toilet and to take reactor to outside of toilet room for matrix
change.
If excess water enters into the reactor, composting reaction will be negatively affected
(Narita et al., 2005). Hence, it is better to put the reactor no lower than ground level, to avoid
submerging in rain season. In this case, the height of toilet room’s wall becomes higher than
current design and extra height also depends on squatting or seating. As far as we asked
people in the site, both of squatting and seating seems to be acceptable. The case of seating,
height of wall can be 20 cm lower than the case of squatting and it saves construction cost
about 5.5 USD. As a prototype, we chose seating style.
Several numbers of prototypes are now being installed at pilot families’ house in Burkina
Faso. The design will be tested in real conditions and improvement-required point will be
abstracted and feed back to improved design.
References
Hiroki Narita, Miguel Angel Lopez Zavala, Kaori Iwai, Ryusei Ito, Naoyuki Funamizu (2005)
Transformation and characterization of dissolved organic matter during the thermophilic aerobic
biodegradation of feces. Water Research 39, 4693-4704
-31-

Japan and China Joint Symposium

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