October 2010 Paper – A Sustainable Business Engineered Water Treatment Solutions

Treatment of Recycled Paper Mill Effluent using Membrane Bioreactors Nampak Tissue Case-Study Wade Edwards*, Peet Zeelie, Marshall Sheldon Engineered Water Treatment Solutions

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 Economic Evaluation: Water Reuse and Recycle

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 6,000Ml per month of polluted industrial effluent is discharged Cost-to-industry R760 million/year South African Situation 20% 13%

Physical Biological Cleaner Production Technical Solutions & Strategies

Compliance with discharge standards Reduction in effluent discharge tariffs Reduction in fresh water consumption Integration with Cleaner Production & Waste Minimisation Economic Viability Assessment

Raw effluent R583,000 Treated effluent R258,000 CAPEX R6,000,000 OPEX R12,000/month RoI 18 months Company – Simba Chips, Bellville Contractor – Project Assignments Water recycle - No Economic Viability Assessment

Biological Treatment AerobicAnaerobic Suspended Growth Fixed Film Trickling filter Fluidized Bed BAF Reed Beds Suspended GrowthFixed Film Anaerobic filter Fluidized Bed Submerged anaerobic filter Anaerobic Contact process UASBABR Sludge digestion SAFRBCMBBR Activated sludge Aerated lagoons Ponds PACT Contact stabilisation Membrane bioreactors BNRSBRDeep shaft A2OA2OUCTVIPMLEBardenphoStep feed?? IC Biological Treatment Processes

° ° ° ° ° ° ° ° ° ° Mechanical pre-treatment Activated sludge tank Submerged MBR ° ° ° ° ° ° ° ° ° ° DenitrificationNitrification Wastewater Cleaned Wastewater B ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° Activated sludge tank DenitrificationNitrification Pre-clarification Mechanical pre-treatment Secondary clarificationDisinfection WastewaterCleaned Wastewater Conventional activated sludge Submerged MBR ° ° ° ° ° ° ° ° ° ° Mechanical pre-treatment Activated sludge tank Sidestream MBR Wastewater Cleaned Wastewater A Sidestream MBR Membrane Bioreactor Process

Membrane Bioreactor Process

OPEX OLR = 3,000kg BOD/day C:N:P ratio = 100 : 0.3 : 0.08 Q = 1.2Ml/d N supp. = R645,000 / year P supp. = R235,500 / year R880,500 / year C:N:P ratio 100:10:1 Process Design Considerations

PHYSICO-CHEMICAL PARAMETERS INORGANIC COMPOSITION DESIGN PARAMETERS BOD/COD ratio = ±0.85 COD/BOD ratio = 1.15 OLR = 3,000kg BOD/d SO 4 /COD ratio = 0.15 C:N:P ratio = 100 : 0.3 : 0.08 C:N:P ratio = 100 : 10 : 1 Q = 1.2Ml/d Summary – Effluent Composition

ANOXIC ANAEROBIC AEROBIC KEY: FEED ANAEROBICANOXICAEROBIC MEMBRANE FILTRATION PRODUCT EGSB Modified Ludzack-Ettinger (MLE) 5Q RECYCLE Process Design Strategy

Piloting – Anaerobic & MBR Anaerobic pre-treatment Aerobic MBR post-treatment 70% COD reduction START-UP 98% COD reduction MBR DURATION

Pilot Plant – NF & RO Nanofiltration polishing Reverse osmosis polishing 99.1% COD reduction 98.8% Ca reduction 98.6% HCO 3 reduction 99.7% COD reduction 98.9% Ca reduction 96.5% HCO 3 reduction

Process Design – Side-stream MBR

Process Design – Immersed MBR

MBR Market Distribution & Segmentation

MBR – Cost of Operation 91% decrease in OPEX

Anaerobic Process Design – UASB/IC UASB/EGSB / IC

Anaerobic Process Design – ABR Anaerobic Baffled Reactor

Economic Viability Assessment NOTE: Anaerobic gas content = 75.5% CH 4 Maximum CH 4 production is 0.35Nm 3 CH 4 per kg COD removed Calorific heat value of methane = 32MJ/Nm 3 CH 4 1kWh = 3.6MJ 70% Anaerobic COD removal efficiency & methane production (75.5% CH 4 ) Net 3,000kWh/d (22,500MJ/d) Net 4,000kWh/d (27,400MJ/d) 85%

Process Segmentation - Anaerobic

Process Segmentation - Anaerobic Anaerobic systems per sector Anaerobic system type distribution

Conclusions ANAEROBIC PRE-TREATMENT Reduces biological loading on MBR – 70% COD reduction Lowers energy requirements, operating costs, and sludge production 0.35Nm 3 CH 4 /kg COD removed; 32MJ/Nm 3 CH 4 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% HCO 3

Conclusions Annual potable water intake costs Annual effluent discharge 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 CAPEX – ROI of 3 years OPEX savings – 85%

Acknowledgements Water Research Commission of South Africa Nampak Tissue

Engineered Water Treatment Solutions Thank you Dr Wade Edwards Managing Director +27 (0) Dr Marshall Sheldon Director of Operations +27 (0)