ZeeWeed MBR Technology Update - SAWEA

1 ZeeWeedZeeWeedMBR MBR Technology Update Technology Update Chris JefferyZENON Environmental IncSAWEA Workshop, 2005 Presentation Outline ZeeWeed MBR Technology ZENON MBR Technology Update New ZENON Projects Q & AZeeWeed MBR TechnologyZeeWeedZeeWeed 500 Flow Diagram500 Flow DiagramPrinciples of ZeeWeedPrinciples of ZeeWeed Immersed MembranesImmersed MembranesMembrane mhairCrypto-sporidiumsmallest micro-organismpolio virusSuspended solidsSuspended solidsParasitesParasitesBacteriaBacteria Org. macro. moleculesOrg. macro. moleculesVirusesVirusesColloidsColloidsD issolved saltsDissolved saltsSand filtrationSand filtrationMicrofiltrationMicrofiltration UltrafiltrationUltrafiltrationNanofiltra tionNanofiltrationReverse OsmosisReverse OsmosisZENON membrane range Reinforced for maximum strength and maximum life Failure proof / double barrier High solids toleranceZeeWeedZeeWeed 500 500 Robust MembraneRobust MembraneZeeWeed Cassette Scale-UpLarger Plants = Larger CassettesZW-500a (1997)4,000 ft280,000 gpdZW-500c (2000)5,500 ft2110,000 gpdZW-500d (2002)

2 16,300 ft2326,000 gpdZeeWeedZeeWeed 500d500d CassetteCassetteOptimized Building BlockOptimized Building Block Compact High packing density = small footprint Low energy costs Accessible Easy to remove modules and cassettes Simple Fewer connections, valves = higher reliability Lower capital costsZeeWeedZeeWeed 500d500d TrainTrainZeeWeed Membrane CassettesPermeate HeaderAir HeaderAir SeparatorMain Permeate HeaderPermeate PumpOverall ZeeWeed MBR DesignSimple, Modular ZeeWeed DesignZW MBR Technical for Change Drivers for Change PreEffective System Design Simplified System Design Cleaning ToolboxComprehensive Cleaning Life Cycle Costs Optimized Life Cycle Costs Life and WarrantyMembrane Life and ConditioningChemical ConditioningTotal Capital CostsTotal Capital Costs05001,0001,5002,0002,500010,00020,0 0030,00040,00050,00060,00070,00080,000 Flow rate, m3/dTotal capital costs ($/m3/d)CASMBRCAS-TFTotal O&M CostsTotal O&M ,00020,00030,00040,00050,00060,00070,000 80,000 Flow rate, m3/dTotal O&M costs ($/m3)

3 CASMBRCAS-TFTotal LifeTotal Life--Cycle CostsCycle ,00020,00030,00040,00050,00060,00070,000 80,000 Flow rate, m3/dTotal life cycle costs ($/m3)CASMBRCAS-TFPre Screening Experience & RecommendationHollow FibreFlat SheetAcceptable Screen Types Internally-fed rotary drum screen In-channel rotary drum screen Rotating brush screen Travelling band screenScreening Requirement 2 mm mesh or punched hole, with no possibility of screenings carry-over or bypass Preferred: 1 mm mesh or punched hole screening European market is well on the way to acceptance of 1 mm screensBrescia, years of operation2-mm Huber in-channel rotary drumSchilde, Belgium2 years of operation1-mm Huber in-channel rotary drumVarsseveld, Netherlands5 months of rotating brushBenefits of Fine ScreeningBenefits of Fine Screening Higher sustainable flux Longer membrane life Longer cleaning intervals Less equipment maintenance Insurance: protection of most valuable asset!

4 Membrane Filtration System DesignFiltration Package Plants Standard MWW units ZENON Standard components Cost savings due to pre-engineeringFull Scope Package PlantsCustom Membrane System Design Reversible pumps Removal of air separator Siphon designs RedundancyNot So Simple DesignCreemoreCauley CreekSimple Design Reversible PumpBioreactorMembraneMixed Liquor RecyclePermeateMembrane AerationCleaning ChemicalSimple Design using Reversible PumpsWoodstockNordKanalPermeate by Gravity / Siphon ZENON uses a Controlled Siphon control valve 25 ft minimum head ZeeWeed MBR plants Lowestof, UK Buxton, UK mgd Linwood, GA 7 mgdunder designMembrane CleaningZENON Cleaning Toolbox In-situ membrane cleaning Reduce handling of membranes Fully automated cleaning procedure Reduce operator requirements Regular, less intense cleaning Maintain a higher membrane permeability Backpulse cleaning chemicals Improved cleaning effectivenessMBR Operation PhilosophiesLong run time with recovery cleaning:-ability to peak with fouled membrane?

5 -ability to recover permeability?PermeabilityFrequent maintenance cleaning:-always ready to peak-cleaning off fresh depositsTimeAutomated Membrane CleaningBioreactorMembraneMixed Liquor RecyclePermeateMembrane AerationCleaning ChemicalEnergy OptimizationMBR Energy UsersBiological Process AerationMembrane AerationAnoxic MixersRAS FlowPermeate FlowMBR Energy UsersBio Process Aeration42%Membrane Aeration34%RAS Pumping10%Permeate Pumping4%Misc1%Anoxic Mixing9%Optimizing Energy Efficiency Biological process aeration Select MLSS to optimize OTE Alpha factor decreases at higher MLSS Limitation on OUR at higher MLSS Nit/DeNitrecovers energy and alkalinity Fine bubble aeration in bioreactor

6 Membrane aeration Optimize membrane depth Cyclic aerationMembrane unit #1 Membrane unit #2 BlowerBlower running continuouslyFast action butterfly valvesBio-Process NPV vs. MLSS ConcentrationMLSS Distribution MLSS membranetank= (R+1) x MLSS bioreactorR024681012141612345678910 Recycle Rate (RQ)Membrane Tank MLSS (g/L)MLSS Distribution MLSS membranetank= (R+1) x MLSS bioreactorR024681012141612345678910 Recycle Rate (RQ)Membrane Tank MLSS (g/L)DesignMembrane Aeration Optimize membrane submergence to reduce blower discharge pressure Effective scouring with course bubble aeration Optimized cyclic aeration based on flowMembrane unit #1 Membrane unit #2 BlowerBlower running continuouslyFast action butterfly valvesUS Patent 6,245.

7 23910/30 Aeration at ADF Optimized cyclic aeration based on flow Maintain 10/10 Aeration at or above ADF Run at 10/30 Aeration below ADF 50% Savings compared to 10/10 = 7-10% LCC10/10 Sequential Aeration 4 blowers on each blower sized to aerate of one trainNote Airflow is blue10/30 Sequential Aeration 2 blowers on each blower sized to aerate of one train same instantaneous air flow rate as 10/10 BUT the averageNote Airflow is blueEvolution of ZeeWeedMembrane (1994)ZW500a(1997)ZW500a(1999)ZW500c(200 0)ZW500d(2003)ZW500d(2005)Cyclic AerationZeeWeed Cassette Scale-UpLarger Cassettes = Lower Capital + O&M CostsIncreasing Size Decreasing $ / galZW-500c (2000)5,500 ft2110,000 gpdZW-500d (2002)16,300 ft2326,000 gpdZW-500d (2005)21,800 ft2436,000 gpdZW-500a (1997)

8 4,000 ft280,000 gpdMembrane Life and WarrantyKey Factors for Key Factors for Extended Membrane LifeExtended Membrane Life Select a robust membrane Protect the membrane Keep the membrane clean Design with a conservative flux Finite life time capacity Design Flux Selection Based on long-term, full-scale experience, rather than short-term data or pilot studies Design based on limiting hydraulic conditions Maximum Flow Minimum Temperature Performance Beyond 5 Years Minimum Safety FactorRecommend Specifying Minimum Membrane Area orMaximum Peak FluxLife Time Membrane CapacityOperating Flux[gfd]5 yrs[gal/ft2]8 yrs[gal/ft2]10 yrs[gal/ft2]15 yrs[gal/ft2]59,12514,60018,25036,50054,7 5027,3751018,25029,20054,7501527,37543,8 0082,125 Chemical ConditioningSludge Quality?

9 Settleabilitynot important Sludge Quality is a factor How do we measure?Which of the following parameters are more important for MBR fouling TTF DSVI MLSS Specific cake resistance Silt density index (SDI) Fouling index (FI) Modified fouling index (MFI) Particle size distribution (> m) Colloidal TOC Soluble EPS Soluble carbohydrate Soluble protein Soluble humic acid Temperature Bound EPS Zeta-potentialWhich of the following parameters are more important for MBR fouling TTF DSVI MLSS Specific cake resistance Silt density index (SDI) Fouling index (FI) Modified fouling index (MFI) Particle size distribution (> m) Colloidal TOC Soluble EPS Soluble carbohydrate Soluble protein Soluble humic acid Temperature Bound EPS Zeta-potentialSludge Quality -TTFS ludge Quality?

10 Chemical Conditioning Coagulants, Polymers Significant Improvements Reliability Design ImplementationNew Projects Traverse City, MIADF: MGD (26,500 m3/d)Commission Date: Summer 2004 Largest operating MBR based on peak flow Peak flow mgd(65,000 m3/d) Primary Clarifier + Fine Screen 8 ZW500 trains Bio-P RemovalPooler, GeorgiaADF: MGD (9,463 m3/d)Commission Date: November, 2004 Located near Savanna, GA 4 ZW500d trains with reversible pumps Simple, cost effective layout & construction Process optimization for flows < design F. Wayne Hill Water Resources CenterADF: 47 MGD (177,914 m3/d)Commission Date: Summer 2005 Largest membrane tertiary filtration plant 16 ZW500 Trains Very strict effluent limits Turbidity < NTU Particle Count < 10#/ml Discharges to Lake Lanier Recreational and indirect potable reuseJackson, Ohio Retrofit of old aeration tanks Will operate in parallel with existing ox ditches 4 trains, reversible pumps Zenon evaluated against other MBRs Selected based on experience and costsADF: 2 MGD (7,571 m3/d)Commission Date: 2006/2007 Brightwater WWTPADF: 31 MGD (117,347 m3/d)Commission Date.