Transcript Wade Edwards - TAPPSA. Technical Association of the Pulp

Engineered Water Treatment Solutions
Paper – A Sustainable Business
19 - 20 October 2010
Engineered Water Treatment Solutions
Treatment of Recycled Paper Mill
Effluent using Membrane Bioreactors
Nampak Tissue Case-Study
Wade Edwards*, Peet Zeelie, Marshall Sheldon
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Economic Evaluation:
Water Reuse and Recycle
 Global water crisis – 40% supply/demand gap by 2030
 Agricultural demand - decrease from 71% - 65% of overall demand
 Domestic demand - decrease from 14% - 12% of overall demand
 Industrial demand – INCREASE from 16% - 22% of overall demand
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South African Situation
 18% supply/demand gap by 2030 (historical trend)
 30% supply/demand gap by 2030 (climate change)
 National ‘Green Drop’ initiative – 3% of WWTPs are
90% compliant
 70% increase in cost of water in past 5 years
R 9.00
Cost per kL (ZAR)
R 8.50
R 8.00
20%
R 7.50
R 7.00
R 6.50
13%
R 6.00
R 5.50
R 5.00
Nov-07 Feb-08 Jun-08 Sep-08 Dec-08 Mar-09
Jul-09
Month / year
Water cost (R/kL)
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 6,000Ml per month of
polluted industrial effluent
is discharged
Effluent cost (R/kL)
Oct-09 Jan-10
 Cost-to-industry
R760 million/year
Technical Solutions & Strategies
 Physical
 Biological
 Cleaner Production
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Economic Viability Assessment

Compliance with discharge standards

Reduction in effluent discharge tariffs

Reduction in fresh water consumption

Integration with Cleaner Production
& Waste Minimisation
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Economic Viability Assessment
Company – Simba Chips, Bellville
Contractor – Project Assignments
Water recycle - No
Raw effluent
R583,000
Monthly Effluent Charge
R 700,000
R 600,000
R 500,000
Treated
effluent
R258,000
R 400,000
R 300,000
CAPEX R6,000,000
OPEX R12,000/month
RoI
18 months
R 200,000
R 100,000
R0
0
1,000 2,000 3,000 4,000 5,000 6,000 7,000 8,000 9,000
Final COD (mg/L)
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Biological Treatment Processes
Biological Treatment
Aerobic
Anaerobic
Suspended Growth
Fixed Film
Trickling
filter
Fluidized
Bed
BAF
Reed
Beds
RBC
SAF
Anaerobic
filter
MBBR
Activated
sludge
Fixed Film
Aerated
lagoons
Suspended Growth
Submerged
anaerobic
filter
A2O
Contact
stabilisation
UCT
Membrane
bioreactors
VIP
BNR
MLE
SBR
Bardenpho
Sludge
digestion
Ponds
Anaerobic
Contact
process
PACT
Fluidized
Bed
Deep shaft
Step feed
??
IC
UASB
ABR
Membrane Bioreactor Process
Conventional activated sludge
Mechanical
pre-treatment
Activated sludge tank
Secondary clarification
Disinfection
Pre-clarification
Denitrification
Nitrification
Wastewater
°
°
Cleaned
Wastewater
°
°
° °
° °
°°
° °
°
°
° °
°°
° °
Sidestream MBR
Submerged MBR
Submerged MBR
Sidestream MBR
Mechanical
pre-treatment
Activated sludge tank
Mechanical
pre-treatment
Wastewater
Wastewater
°
A
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°
°
°
° °
°°
° °
Activated sludge tank
°
Cleaned
Wastewater
B
Cleaned
Wastewater
Denitrification Nitrification
°
°
°
° °
°°
° °
°
°
° °
° °
°°
° °
Membrane Bioreactor Process
2
1
6
5
7
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3
4
Process Design Considerations
Q = 1.2Ml/d
OLR = 3,000kg BOD/day
C:N:P ratio = 100 : 0.3 : 0.08
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C:N:P ratio
100:10:1
OPEX
N supp. = R645,000 / year
P supp. = R235,500 / year
R880,500 / year
Summary – Effluent Composition
PHYSICO-CHEMICAL
PARAMETERS
pH
pH units
Temperature Cº
6.44 (4.4 - 6.8)
37
1,845 (1,203 - 2,530)
Conductivity
TDS
Turbidity
COD
BOD
(µS/cm)
mg/L
NTU
mg/L
mg/L
TSS
mg/L
124
(19 - 447)
NH4-N
NO3-N
P
mg/L
mg/L
mg/L
5.18
(3.9 - 7.1)
1,185 (457 - 1,760)
220
(61 - 868)
2,950 (1,362 - 4,481)
2,400
5
2.3
DESIGN
PARAMETERS
BOD/COD ratio = ±0.85
COD/BOD ratio = 1.15
Q = 1.2Ml/d
OLR = 3,000kg BOD/d
SO4/COD ratio = 0.15
C:N:P ratio = 100 : 0.3 : 0.08
C:N:P ratio = 100 : 10 : 1
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INORGANIC
COMPOSITION
Na
K
Ca
Mg
Fe
Cl
CO3
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
162
9
365
15
0.26
141
N/A
HCO3
mg/L
1,018
SO4
B
Mn
Cu
Zn
F
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
454
1.15
0.06
0.002
0.15
0
Process Design Strategy
3
2
1
5Q RECYCLE
4
KEY:
6
5
PRODUCT
FEED
ANAEROBIC
EGSB
1
3
ANOXIC
AEROBIC
MEMBRANE
FILTRATION
Modified Ludzack-Ettinger (MLE)
4
5
6
2
ANAEROBIC
ANOXIC
AEROBIC
Piloting – Anaerobic & MBR
MBR DURATION
100
80
3,000
2,500
60
2,000
40
1,500
1,000
70% COD reduction
20
COD Removal (%)
3,500
COD (mg/L)
Anaerobic
pre-treatment
START-UP
4,000
500
0
0
0
50
100
150
200
Operating Time (days)
Effluent COD
COD Removal
4,000
100
3,500
2,500
60
2,000
40
1,500
1,000
98% COD reduction
20
500
0
0
0
20
40
60
80
100
Operating Days
Product COD
Permeate COD
Effluent COD
Overall COD removal
120
COD removal (%)
80
3,000
COD (mg/L)
Aerobic MBR
post-treatment
Product COD
Pilot Plant – NF & RO
Nanofiltration
polishing
PHYSICO-CHEMICAL PARAMETERS
Parameter
Units
Conductivity
Reverse osmosis
polishing
99.7% COD reduction
98.9% Ca reduction
96.5% HCO3 reduction
NF
% MBR
% Overall
µS/cm
1,380
940
70
32
94.9
mg/L
1,038
711
51
32
95.1
COD
mg/L
2,105
40
19
98
99.1
INORGANIC COMPOSITION
Parameter
98.6% HCO3 reduction
MBR
TDS
99.1% COD reduction
98.8% Ca reduction
Effluent
Effluent
MBR
NF
% MBR
% Overall
Na
mg/L
Units
110
118
11.3
N/A
89.7
Ca
mg/L
250
79
3
68
98.8
Mg
mg/L
9.6
10
0.3
N/A
96.9
Cl
mg/L
57
79
9.7
N/A
82.8
HCO3
mg/L
763
338
10.7
56
98.6
SO4
mg/L
345
72
6
79
98.3
Parameter
Units
Effluent
MBR
RO
% MBR
% Overall
Conductivity
PHYSICO-CHEMICAL PARAMETERS
µS/cm
2,100
980
94.2
53.3
95.5
TDS
mg/L
1,587
743
69.7
53.2
95.6
COD
mg/L
2,280
58
6
97.5
99.7
% MBR
% Overall
INORGANIC COMPOSITION
Parameter
Units
Effluent
MBR
RO
Na
mg/L
110
104.4
12.8
5.1
88.3
Ca
mg/L
433
82.46
4.7
80.9
98.9
Mg
mg/L
11.2
10.44
0.4
6.8
96.3
Cl
mg/L
74.9
73.14
15.0
2.3
80.0
HCO3
mg/L
1,100
651
38.2
40.8
96.5
SO4
mg/L
133
86.08
15.2
35.3
88.5
Process Design – Side-stream MBR
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Process Design – Immersed MBR
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MBR Market Distribution
& Segmentation
3 50
Number of MBR insta llations
450
400
Membrane cost (€/m2)
350
300
250
200
150
100
50
0
1990
3 00
Industrial (>20 m3 /da y)
Municipal (>500 p.e )
2 50
2 00
1 50
1 00
50
0
1992
1994
1996
1998
2000
2002
2004
2006
2008
199 7 19 98
1999
2000
200 1 2 002
2003
2004
200 5
North America
11%
Europe
16%
Asia
73%
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Membrane sur face ar ea (x1000m2)
Year
600
500
Industr ial
Municipal
400
300
200
100
0
1997 1998 1999 2000 2001 2002 2003 2004 2005
MBR – Cost of Operation
91% decrease
in OPEX
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Anaerobic Process Design – UASB/IC
UASB/EGSB / IC
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Anaerobic Process Design – ABR
Anaerobic Baffled Reactor
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Economic Viability Assessment
Anaerobic COD removal efficiency
& methane production (75.5% CH4)
10,000
10,000
1,100
5,000
500
4,000
300
3,000
2,000
100
1,000
7,000
700
6,000
5,000
500
4,000
300
3,000
2,000
100
1,000
0
0
500
1,000
1,500
2,000
2,500
3,000
3,500
-100
4,000
0
0
500
1,000
Influent COD (mg/L))
Energy Produced kWh/d
Net energy kWh/d
1,500
2,000
2,500
3,000
3,500
-100
4,000
Influent COD (mg/L))
CH4 produced Nm3/d
Net 3,000kWh/d
(22,500MJ/d)
Energy Produced kWh/d
Net energy kWh/d
CH4 produced Nm3/d
Net 4,000kWh/d
(27,400MJ/d)
NOTE:
• Anaerobic gas content = 75.5% CH4
• Maximum CH4 production is 0.35Nm3 CH4 per kg COD removed
• Calorific heat value of methane = 32MJ/Nm3 CH4
• 1kWh = 3.6MJ
CH4 produced (Nm 3/d)
700
6,000
900
85%
8,000
Energy (kWh/d)
7,000
CH4 produced (Nm 3/d)
900
70%
8,000
Energy (kWh/d)
1,100
9,000
9,000
Process Segmentation - Anaerobic
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Process Segmentation - Anaerobic
Anaerobic system
type distribution
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Anaerobic systems
per sector
Conclusions
ANAEROBIC PRE-TREATMENT
• Reduces biological loading on MBR – 70% COD reduction
• Lowers energy requirements, operating costs, and sludge
production
• 0.35Nm3 CH4/kg COD removed; 32MJ/Nm3 CH4
MEMBRANE BIOREACTOR
• MBR – 98% overall COD reduction; 99% TSS reduction
• Integrated pre-treatment for NF or RO
EFFLUENT POLISHING (NF & RO)
• 95% overall TDS reduction; 98% Ca reduction; 96% HCO3
Conclusions
Annual potable water intake costs
Potable 1.0Ml/day – R3.3 million/yr
Effluent 1.0Ml/day – R2.5 million/yr
Potable 2.0Ml/day – R3,3 million/yr
Effluent 2.0Ml/day – R6.6 million/yr
Cost - R('000)
R 10,000
R 8,000
R 6,000
R 4,000
R 2,000
R0
2007-2008
Annual effluent discharge costs
R 7,000
2008-2009
2009-2010
2010-2011
Financial year
0.5Ml/d
1.0Ml/d
1.5Ml/d
2.0Ml/d
2.5Ml/d
Cost - R('000)
R 6,000
R 5,000
R 4,000
CAPEX – ROI of 3 years
R 3,000
R 2,000
OPEX savings – 85%
R 1,000
R0
2007-2008
0.5Ml/d
2008-2009
1.0Ml/d
2009-2010
1.5Ml/d
2.0Ml/d
2010-2011
2.5Ml/d
Acknowledgements
 Water Research Commission
of South Africa

Nampak Tissue
Engineered Water Treatment Solutions
Thank you
Dr Wade Edwards
Managing Director
+27 (0) 83 441 0450
Dr Marshall Sheldon
Director of Operations
+27 (0) 72 485 3171
[email protected]
[email protected]
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