O - Senai

Industrial wastewater treatment success cases at
Centre des Technologies de l’Eau (CTE) in
Canada
Aziz Gherrou, Ph.D., Chemist/Researcher
Tél. : 514 747-2782 ext. 4
E-mail : [email protected]
SENAI, Paraná, November 18th, 2014
HEXAVALENT CHROMIUM REMOVAL
FROM ELECTROPLATING INDUSTRIES
RINSING WATERS
Cementation
Exchange of metal less electronegative with
another metal more electronegative
E10 < E20
∆E⁰⁰ = (E⁰⁰ (acceptor) E⁰⁰ (donor) ) > 0
Réduction (accepteurs)
Cu2+(aq) + 2 e– ↔ Cu(s)
Ag+ (aq) + e- ↔ Ag(s)
Au+(aq) + e– ↔ Au(s)
Au3+(aq) + 3 e– ↔ Au(s)
Eº(V)
+0,33
+0.80
+1.68
+1,50
Oxydation (donneurs)
Fe(s) ↔ Fe2+ (aq) + 2eFe(s) ↔ Fe3+ (aq) + 3eZn(s) ↔ Zn2+(aq) + 2 e–
Eº(V)
+0.44
+0.04
+0,76
New approach: metal exchange
Reduction (electron acceptor)
Eº(V)
Eº(V)
+1,33
Oxydation (electron
donor)
Fe(s) ↔ Fe2+ (aq) + 2e-
Cr2O72- + 14H+ + 6e- ↔ 2Cr3+ + 7H2O
HCrO4- + 7H+ + 3e- ↔ Cr3+ + 4H2O
+1,20
Fe(s) ↔ Fe3+ (aq) + 3e-
+0.04
+0.44
0<pH<6.5
2HCrO4- (aq)+ 14H+ (aq) + 3Fe0 (s) → 2Cr3+ + 3Fe2+(aq) + 8H2O (l)
pH>6.5
2CrO42- (aq) + 3Fe0 (s) + 8H2O → 2Cr3+ + 3Fe2+(aq) + 16HO- (l)
pH<2
2HCrO4- (aq)+ 14H+ (aq) + 3Fe0 (s) → 2Cr3+ + 3Fe2+(aq) + 8H2O (l)
Existing technology, new applications?
Silver recovery from
film-based photoimaging (medical xray, graphic-arts,
industrial x-ray, and
photo-finishing)
wastewaters.
Photo labs market down
New applications
Plating and
electroplating
Metallurgy
Ink
Glass
Textile
Tannery
Chromium discharge limits
World Health Organisation (WHO) and Quebec
RQEP drinking water standards.
Total Chromium : 0.05 mg/l
Montreal Metropolitan Community 2008-47 standard
for industrial wastewaters
Total Chromium : 5 mg/l
Hexavalent chromium : 2.5 mg/l
Classical treatment processes
Adsorption (ion exchange, specific resins,
adsorptive materials).
Membrane processes (reverse osmosis,
electrodialysis, nanofiltration,
ultrafiltration).
Chemical processes (coagulation, chemical
and electrochemical precipitation,
complexation, solvent extraction).
Biological processes (bio-reduction, bioremediation).
Physico-chemical chromium recovery process
Transportation,
storage, handling
and utilisation of
hazardous and
dangerous
chemicals,
Produces
significant
quantities of
hazardous sludge.
o $$$
o Environmental
issues
Pilot plant
New approach
Lab scale validation tests
Peristaltic pump
Power head
Contaminated
effluent (inlet)
Treated wastewater
(outlet)
Iron fiber cartridge
Laboratory scale tests main result
pH initial =3. Flow rate 10 ml/min. Contact time 16.6 min.
Time (min)
Before
treatment
0,6
1
2
3
5
10
15
pH
Conductivity
(µS/cm)
[Cr6+]
(ppm)
[Cr total]
(ppm)
Chrome total
Removal (%)
3,03
6,24
6,69
6,78
6,85
6,86
6,72
6.70
225
1815
1540
1197
887
543
283
220
16
0,15
0,2
0,2
0,12
0,0
0
0
20
0,44
0,26
0,21
0,17
0
0
0
97,8
98,7
98,9
99,1
100
100
100
Significant increase of pH
Cr(VI) is completely reduced
to Cr(III).
Cr(III) precipitates inside the
column
Conductivity increases at the
beginning and then decreases
due to formation of Fe(II) ions
which are oxidized to Fe(III)
and precipitates.
100% REMOVAL OF TOTAL
CHROMIUM
Semi-pilot scale tests on an annodizing
plant wastewater (Montreal)
pH initial= 3.5
Column filled with 13,5 kg
of iron fiber,
Flow rate : 880 ml/min
Pilot scale unit as installed in an electroplating shop in
Montreal.
New iron fiber
Used fiber inside the column
Recycle in Fe-Cr alloys
Project’s budget: 498100$. 60% funded by
economical development, industry and
exportation ministry of Quebec (Canada)
Patented technology. WO 2013078553 A1
PHENOLS DEGRADATION WITH
ADVANCED OXIDATION PROCESSES (AOPs)
AND BIOLOGICAL PROCESSES
Montreal Metropolitan
Community 2008-47
standard for industrial
wastewaters : Total
phenols = 1 ppm
Enerkem converts mixed waste and residues into a pure synthesis gas (or
syngas) which is suitable for the production of biofuels and chemicals
using proven, well-established and commercially available catalysts.
Contaminated wastewater with phenols
EFFLUENTS COMPOSITION
Table 1: Total phenols concentrations
and COD of the effluent
Total phenol
concentration
Reservoir
(mg/L)
1
2
3
4
66
73
81
290
COD
(ppm)
pH
2140
2284
2276
3940
8.4
8.5
8.4
8.5
TREATMENT PROCESS CHOICE
AOPs
– Ozonation at pH >8.5
– Ozone + Hydrogen peroxide (O3/H2O2)
– O3/UV
Biological processes.
Pilot scale tests
Ozone ceramic
diffuser
Ozone generator
10-60 g O3/h
Venturi
Microfilter
5-25 microns
Contact column 150
liters capacity
Ozone oxidation at pH>8.5
Effet of ozone dose
UV/Ozone
Ozonation at pH 10. Ozone dose 0.4 g/L/h.
UV lamp Sanitron S2400 B. 30,000 µWSec/cm2.
Ozone/H2O2
Effet of hydrogen peroxide dose on phenols degradation. Ozonation
at pH=10, Ozone dose= 0.4 g/L/h
• 0.22 g/L de peroxyde
•1.1 g /L de peroxyde
Visual aspect of
samples after
treatment,
AEROBIC BIOLOGICAL TREATMENT
Tests on more
concentrated sample
COD : 8937 mg/L
BOD5 : 6580 mg/L
Phenols : 2200 mg/L
Tests with 3 Sequencing Batch Reactors
1.
SBR with an RST (rate and solid
retention time) = 3 days
2.
SBR wuth an RST = 10 days
3.
MBBR (moving bed biorecator)
F/M (food to mass) = 0,3 d-1
HRT (hydraulic retention time) = 5 d
Biomass :
Activated sludge from a similar wastewater treatmnet plant.
Compost extract adapted to the effluent.
Toxicity tests on biomass
Respirometry tests (OECD protocol 209).
BOD tot
Feed (mg/L)
6580
Effluent (mg/L) 22
52
168
∆
-99,7% -99,2% -97,4%
BOD sol
Feed (mg/L)
5375
Effluent (mg/L) 15
14
37
∆
-99,7% -99,7% -99,3%
SS
SBR-1 SBR-2 MBBR
Feed (mg/L)
Effluent (mg/L)
negligible
139
408
1130
BOD
and SS
COD
COD tot
Feed (mg/L)
8938
Effluent (mg/L) 896
1272
2386
-90,0% -85,8% -73,3%
∆
COD sol
SBR-1 SBR-2 MBBR
Feed (mg/L)
8625
Effluent (mg/L) 758
655
940
-91,2% -92,4% -89,1%
∆
Phenols
Phe. Tot.
SBR-1
Feed (mg/L)
Effluent (mg/L)
SBR-2
MBBR
2340
1,6
∆ -99,93%
1,5
3,4
-99,94%
-99,85%
Treatment solution
SBR
AOP
O3/H2O2
Project’s budget: 62057$. 100% funded by the company,
GREYWATER TREATMENT WITH
ELECTROCHEMICAL PROCESSES
Grey water from laundries
A starting small
manufacturer of
wastewater treatment
technologies
Develop new technologies
for grey water treatment
market
Commercial laundries
Hospital laundries
Industrial laundries
Laundry greywater composition
Table 1: Composition of a commercial laundry’s
wastewater (our project)
Challenge: Removal of
suspended solids, disolved
solids, organic disolved mater,
oil and grease
Paramètres
pH
Conductivity (µS/cm)
Turbidity (NTU)
SS (mg/L)
CODT (mg/L)
DBO5 (mg/L)
TOC (mg/L)
OIL & GREASE (mg/L)
Phosphorous total (mg/L)
NTK (mg/L)
N-NH3 (mg/L)
Nonyl-phenol (µg/L)
Fecal coliforms (UFC/mL)
Total Coliforms (UFC/mL)
BHAA (UFC/mL)
Effluent 1
10.92±0.0
567±0.0
97.4±1.4
55.5±0.70
752.73±0.11
191±2.82
217.3±2.12
116.0±5.65
1.13±0.09
9.37±0.0
<1
<1
<10
<10
9
Effluent 2
10.74±0.02
476±0.0
87.7±0.28
50.0±1.41
652.55±0.83
147±0.0
231.1±2.96
95.5±6.36
1.03±0.09
8.06±0.26
<1
<1
-
Greywater treatment options
Choice of
method:
the
treatment
Quantity and quality of grey
water.
The final utilisation of
treated grey water.
Cost.
Local standards.
(Illustration: Jenssen et al. 2005)
Electrotechnologies
Advantages
Non polluting
Ease of automation
Compact systems
Elimination or reduction of sludge
volume
Production in situ of strong chemical
oxidants
36
EC-ER PROCESS
Electrocoagulation
Anodic reaction:
Aluminum anode
:
Iron anode :
−
3+
Al → Al + 3 e
+
+
−
−
2
+ 2 OH
Fe → Fe 2 ( Fe 3 ) + 2e (3e )
Cathodic reaction:
−
2 H 2O + 2 e → H
−
Reaction in solution:
Precipitation : Al(OH)3, Fe(OH)3 or Fe(OH)2
Co-precipitation (or electrostatic attraction) of pollutants (L)
L − H ( aq ) + ( HO ) OFe ( s ) → L − OFe ( s ) + H 2 O
L − H ( aq ) + ( HO)(OH ) 2 Al( s ) → L − (OH ) 2 Al( s ) + H 2O
37
Electro-reduction
R
O2
RO + H2O
H2 O2
RX
ROOH + HX
Amorphous carbon
Graphite
Vitruous carbon
Cristal carbon
38
Electrocoagulation-Electroreduction (EC-ER) tests with Al and Fe anodes
Parameters
Test 1
Anode type
Aluminum
Type of cathode
Graphite
Current intensity (A)
1.0
Tension (V)
75
Electrolysis time (min)
90
Energy consumption
56.25
(Kwh/m3)
Volume of greywater (L)
2.0
Distance inter-electrode (cm)
3.0
pH initial
10.9
pH final
10.1
SS initial (mg/L)
64
SS final (mg/L)
45
SS reduction (%)
29.68
Turbiditéy initial (NTU)
101
Turbidity final (NTU)
21.2
Turbidity reduction (%)
79.0
CODT initial (mg/L)
868
CODT final (mg/L)
580
CODT reduction (%)
33.17
TOC initial (mg/L)
263..6
TOC final (mg/L)
151.8
TOC reduction (%)
42.41
Test 2
Iron
Graphite
1.0
47
90
35.25
2.0
3.0
11.1
10.9
72
23
68.05
108
16.9
84.35
829
439
47.04
234.2
135
42.35
(a)
(b)
EC-ER tests with 2 different anodes:
(a) aluminum and (b) iron.
Effect of current intensity on greywater treatment with EC-ER
Parameter
Test 1
Test 2
Test 3
Test 4
Test 5
Aluminium
Aluminium
Aluminium
Aluminium
Aluminium
Graphite
Graphite
Graphite
Graphite
Graphite
Current intensity (A)
0.2
0.4
0.8
1.0
1.5
Tension (V)
28
40
47
87
87
Electrolysis time (min)
90
90
90
90
90
Energy consumption (Kwh/m3)
8.4
24
56.4
130.5
130.5
Greywater volume (L)
1.0
1.0
1.0
1.0
1.0
Distance inter-electrode (cm)
Anode
Cathode
3.0
3.0
3.0
3.0
3.0
Temperature initial (°C)
-
-
-
-
-
Temperature final (°C)
21
33
68
83
-
pH initial
9.74
9.74
9.74
9.74
10.9
pH final
9.16
9.71
9.29
10.07
9.9
SS initial (mg/L)
60
60
60
60
64
SS final (mg/L)
15
18
106
13
182.8
SS reduction (%)
75
70
-
78.3
-
Turbidity initial (NTU)
90.6
90.6
90.6
90.6
101
Turbidity final (NTU)
49.5
23.4
11.9
8.5
31
Turbidity reduction (%)
45.36
74.17
86.86
90.61
69.30
CODT initial (mg/L)
673
673
673
673
868
CODT final (mg/L)
380
353
212
183
690
CODT reduction (%)
43.53
47.54
68.49
72.80
20.50
CODs initial (mg/L)
497
497
497
497
-
CODs final (mg/L)
355
261
202
179
-
CODs reduction (%)
28.57
47.48
59.35
63.98
-
TOC initial (mg/L)
186.5
186.5
186.5
186.5
263.6
TOC final (mg/L)
107.9
84.64
47.92
48.98
217.6
TOC reduction (%)
42.41
54.61
74.30
73.73
17.45
DOC initial (mg/L)
133.4
133.4
133.4
133.4
-
DOC final (mg/L)
106.6
61.07
49.53
48.65
-
DOC reduction (%)
20.08
54.22
62.87
63.53
-
Maximum 1 A/L
SS reduction 78%
Turbidity reduction 90%
COD total reduction 72%
COD soluble reduction 64%
TOC reduction 75%
DOC reduction 63%
Effet of initial pH on greywater treatment with EC-ER process
Parameter
Anode
Cathode
Current intensity (A)
Tension (V)
Electrolysis time (min)
Energy consumption (Kwh/m3)
Greywater volume (L)
Distance inter-electrode s(cm)
Temperature initial (°C)
Temperature final (°C)
pH initial
pH initial adjusted
pH final
SS initial (mg/L)
SS final (mg/L)
SS reduction (%)
Turbidity initial (NTU)
Turbidity final (NTU)
Turbidity reduction (%)
CODT initial (mg/L)
CODT final (mg/L)
CODT reduction (%)
CODs initial (mg/L)
CODs final (mg/L)
CODs reduction (%)
TOC initial (mg/L)
TOC final (mg/L)
TOC reduction (%)
DOC initial (mg/L)
DOC final (mg/L)
DOC reduction (%)
Test 1
Al
Gr
1.0
48
90
72
1.0
3.0
19
36
10.48
10.45
69
13
81.0
82.6
6.1
92.6
780.6
229.29
71
663.35
235.21
65
245.2
72.66
70
210.4
75.95
64
Test 2
Al
Gr
1.0
50
90
75
1.0
3.0
13
72
10.64
5
10.25
53.75
3.2
94
94.3
8.24
91.3
800
302
62.25
706
282
60.05
231.1
98.46
57.39
-
Test 3
Al
Gr
1.0
47
90
70.5
1.0
3.0
13
61
10.48
6
10.38
40.69
26.25
35
80.2
21.7
72.9
800
344
57
702
344
51.0
231.1
103.5
55.21
-
Test 4
Al
Gr
1.0
56
90
84
1.0
3.0
15
70
10.48
7
10.78
53.75
42.5
20.9
82
5.42
83.3
794
228
71.3
702
217
69.1
231.5
73.06
68.44
208.5
-
Test 5
Al
Gr
1.0
60
90
90
1.0
3.0
16
71
10.48
8
10.75
45
28
37
84.7
5.46
93.3
801
252
68.5
706
240
66
236.5
74.38
68.54
213
70.17
67.05
Test 6
Al
Gr
1.0
60
90
90
1.0
3.0
13
72
10.48
9
10.63
62.95
13
79
87.2
7.15
91.6
794
261
67.1
685
235
65.7
239.1
76.70
67.92
211.6
75.07
64.52
The process is
efficient in a large
pH domain
Effet of ozone dose on greywater treatment
Parameter
Dose of O3 (g/h)
Treatment duration (min)
Volume (L)
pH initial
pH final
Turbidity initial (NTU)
Turbidity final (NTU)
Turbidity reduction (%)
SS initial (mg/L)
SS final (mg/L)
SS reduction (%)
CODT initial (mg/L)
CODT final (mg/L)
CODT reduction (%)
CODs initial (mg/L)
CODs final (mg/L)
CODs removal (%)
TOC initial (mg/L)
TOC final (mg/L)
TOC reduction (%)
DOC initial (mg/L)
DOC final (mg/L)
DOC reduction (%)
Test 1
2.85
180
1.0
8.00
8.03
89
73
18
50
43.13
13.74
660
530
19.7
514
458
10.89
203
182
10.34
155
134.3
13.35
Test 2
4.35
180
1.0
8.00
8.05
89
60.7
31.8
50
37.5
25.0
660
465
29.54
514
390
24.12
203
152.7
24.77
155
113.8
26.58
Test 3
5.30
180
1.0
8.00
8.05
89
58
34.83
50
28.75
42.5
660
409
38.03
514
318
38.13
203
138.7
31.67
155
98.66
36.35
Test 4
7.1
180
1.0
8.00
8.07
89
57
36.00
50
660
400
39.40
514
310
39.68
203
136
33.00
155
95.20
38.58
Test 5
10.0
180
1.0
8.00
8.04
89
55.5
38.64
50
28.4
43.2
660
372
43.64
514
297
42.21
203
134
34.00
155
90.11
41.86
Max dose about
5 g O3/L
Average 35% of
soluble organic
matter
reduction
Full spectrum of optimal parameters for the ozonation process. Duplicated test. Ozone dose: 10 g/h/l. pH initial: 8
Parametrer
SS initial (mg/L)
SS final (mg/L)
SS reduction (%)
Turbidity initial (NTU)
Turbidity final (NTU)
Turbidity reduction (%)
CODT initial (mg/L)
CODT final (mg/L)
CODT reduction (%)
CODs initial (mg/L)
CODs final (mg/L)
DCOs reduction (%)
TOC initial (mg/L)
TOC final (mg/L)
TOC reduction (%)
DOC initial (mg/L)
DOC final (mg/L)
DOC reduction (%)
Oil & Grease initial (mg/L)
Oil & Grease final (mg/L)
Oil & Grease reduction (%)
BOD5 initial (mg/L)
BOD5 final (mg/L)
DBO5 reduction (%)
N-NTK initial (mg/L)
N-NTK final (mg/L)
N-NTK reduction (%)
Phosphorous total initial (mg/L)
Phosphorous total final (mg/L)
Phosphorous total reduction (%)
Sample
Test 1
48
42
12.5
71
65
8.45
651
355
45.46
514
262
49.02
199
103.6
47.93
155
94.53
39.01
71.75
52.75
26.5
252.66
204.1
19.2
1.31
0.56
57.3
0.84
0.83
1.2
Test 2
40
16.66
64
9.85
363
44.23
246
52.14
127.1
36.13
88.85
42.67
77.5
63.12
18.55
190.8
24.5
0.56
57.3
0.84
0.84
0.0
Average reduction
(%)
14.60±2.94
9.15±0.98
44.84±0.86
50.6±2.2
42.03±8.34
40.84±2.6
77.5
22.52±5.62
21.85±3.74
57.3±0.0
1.2±0.0
Reduction of
about 40% of
soluble matter
Treatment with hybrid electrochemical processes
44
Parameter
Scenario 1
(O3-EC-ER)
SS initial (mg/L)
Ss final (mg/L)
SS reduction (%)
Turbidity initial (NTU)
Turbidity final (NTU)
Turbidity reduction (%)
CODT initial (mg/L)
CODT final (mg/L)
CODT reduction (%)
CODs initial (mg/L)
CODs final (mg/L)
CODs reduction (%)
TOC initial (mg/L)
TOC final (mg/L)
TOC reduction (%)
DOC initial (mg/L)
DOC final (mg/L)
DOC reduction (%)
Oil & Grease initial (mg/L)
Oil & Grease final (mg/L)
Oill & Grease reduction (%)
BOD5 initial (mg/L)
BOD5 final (mg/L)
BOD5 reduction (%)
N-NH3 initial (mg/L)
N-NH3 final (mg/L)
N-NH3 reduction (%)
N-NTK initial (mg/L)
N-NTK final (mg/L)
N-NTK reduction (%)
Phosphorous total initial (mg/L)
Phosphorous total final (mg/L)
Phosphorous total reduction (%)
59
21.5
63.55
83
5.2
93.73
645
196
69.61
519
174
67.12
199.7
58.84
70.53
156.9
42.96
72.61
301.63
36.08
88.03
5.62
4.5
19.92
0.90
0.11
87.77
Grey water
Scenario 2 (EC-ER-O3)
Test 1
Test 2
Removal
average yield
(%)
59
59
14
10
76.27
83.05
79.66±4.79
83
83
2.3
2.0
97.22
97.59
97.40±0.26
645
645
61
51
90.54
92.09
91.31±1.09
519
519
52
50
89.98
90.36
90.17±0.26
199.7
199.7
28.35
33.18
85.8
83.38
84.59±1.71
156.9
156.9
25.61
30.50
83.67
80.56
82.11±2.19
113.25
113.25
10.62
11.12
90.62
90.18
90.40±0.31
301.63
301.63
21.75
22.78
92.78
92.44
92.61±0.24
2.0
2.0
0.95
1.1
52.5
45.0
50.62±2.65
5.62
5.62
3.0
3.15
46.61
43.95
45.28±1.88
0.90
0.90
0.12
0.12
86.66
86.66
86.66±0.00
Combination of EC-ER with
a post ozonation increases
the treatment efficiency up
to 90% of COD, 82% of
DOC and TOC, 90% of oil
and grease, 92% BOD and
86% of phosphorous.
Polishing with membrane
filtration.
Project’s budget: 25000$. 100%
funded by NSERC (Canada)
45
E-mail : [email protected]