Deborah Helstrom, P.E. Utilities Technical Review Water Supply Division Membrane Bioreactors Treatment Systems (MBR)

  Information used to draft   What it contains   How to use the rule Membrane Bioreactors Treatment Systems (MBR)

Compiled Surveys from Vendors of Membranes Huber, Koch, Kruger, Kubota, Siemens, Zenon Huber, Koch, Kruger, Kubota, Siemens, Zenon Results of Survey, Literature and Other State Regulations Concerns Prevention of Fouling Prevention of Fouling Adequate aeration at high MLSS concentrations Adequate aeration at high MLSS concentrations Achievable rate of flow through membranes Achievable rate of flow through membranes Adequate pretreatment i.e. fine screening Adequate pretreatment i.e. fine screening Hydraulics Hydraulics Ensure Integrity Ensure Integrity Foam Control Foam Control Warranty Warranty Nutrient Removal Nutrient Removal Membrane Bioreactors (MBR)

Applicability Submerged Submerged Low-pressure, vacuum or gravity Low-pressure, vacuum or gravity Ultrafiltration or microfiltration Ultrafiltration or microfiltration 217.8(b)(2) Approval of Nonconforming and Innovative Technologies 217.8(b)(2) Approval of Nonconforming and Innovative Technologies May require pilot study and/or 2 year performance bondMay require pilot study and/or 2 year performance bond Membrane Bioreactors (MBR)

CBOD55 mg/lCBOD55 mg/l TSS1 mg/lTSS1 mg/l Ammonia1 mg/lAmmonia1 mg/l Total Nitrogen (w/pre-anoxic zone)10 mg/lTotal Nitrogen (w/pre-anoxic zone)10 mg/l Total Nitrogen (w/pre-anoxic andTotal Nitrogen (w/pre-anoxic and post-anoxic zone)3 mg/l post-anoxic zone)3 mg/l Total Phosphorus (with chemical addition)Total Phosphorus (with chemical addition) 0.2 mg/l0.2 mg/l Total Phosphorus (with Bio-P removal)Total Phosphorus (with Bio-P removal) 0.5 mg/l0.5 mg/l Turbidity 0.2 NTUTurbidity 0.2 NTU Bacteriaup to 6 log removal ( %)Bacteriaup to 6 log removal ( %) Virusesup to 3 log removal ( %)Virusesup to 3 log removal ( %) If proposed design is for higher quality effluent, Pilot Study or Data from Similar Facility Membrane Bioreactors (MBR) Expected Performance

Membranes Hollow fiber or Flat plate Nominal Pore Size Microfiltration 0.10 – 0.40 microns Ultrafiltration 0.02 to 0.10 microns Common Membrane materials Pretreatment Fine Screen - perforated plate or drum Hollow fiber mm Flat plate mm No Bypass Primary clarifier Evaluated for > 1 MGD Grit Removal excessive I/I Oil and Grease Removal 50 mg/l Membrane Bioreactors (MBR)

Operation Average Daily Net flux 20 C 12 to 20 gfd Peak Daily Net flux 20 C 20 gfd Two Hour Peak Daily Net flux 20 C 24 gfd Operational Range for TMP Maximum Operational TMP Hollow Fiber 2.0 – 10.0 psi Max 12.0 psi Flat Plate psi Max 3.0 psi Operational Range of MLSS Concentration Bio Reactor 4, ,000 mg/l Bio Reactor 4, ,000 mg/l Membrane Tank 4,000 – 12,000 mg/l Membrane Tank 4,000 – 12,000 mg/l Operational control parameters SRT 10 – 25 days SRT 10 – 25 days Membrane Bioreactors (MBR)

Operation Amount of air used per square foot of membrane 0.01 – 0.04 SCFM / SF Method of Integrity Testing : In-line Turbidity <=1.0 NTU Hollow Fiber Pressure Decay Testing Surface Wasting to Foam Control Run in full manual mode or backup PLC Aeration alpha value of 0.5 or lower anoxic 0.5 mg/l DO aerobic 1.5 – 3.0 mg/l DO membrane mg/l DO Nutrient Removal deoxygenate recycle recycle 300 – 600 percent Membrane Bioreactors (MBR)

Redundancy N+1, trains, units or storage. Show calculations Peak Flow Peak Ratio of 2.5 requires Equalization, off-line storage or reserve membrane capacity RAS rate 200 – 400 percent of influent Warranty 5 year on Membranes May require a 2 year performance bond Membrane Bioreactors (MBR)

Engineering Report Required Engineering Report Required Common range of values Common range of values Justification for using parameters outside the common range Justification for using parameters outside the common range May be required to provide 2 year performance bond May be required to provide 2 year performance bond Membrane Bioreactors Treatment Systems (MBR)

“So, You Decided to Build an MBR?: Tips to help optimize process performance”, Merlo, Rion et al, WE&T, November “So, You Decided to Build an MBR?: Tips to help optimize process performance”, Merlo, Rion et al, WE&T, November November November 2006 State of Washington, Department of Ecology, “Orange Book”, Sewage Treatment Design Criteria State of Washington, Department of Ecology, “Orange Book”, Sewage Treatment Design Criteria Water Environment Federation, Membrane Systems for Wastewater Treatment, 2006 Water Environment Federation, Membrane Systems for Wastewater Treatment, 2006 Manufacturers: Manufacturers: Huber, Koch, Kruger, Kubota, Siemens, ZenonHuber, Koch, Kruger, Kubota, Siemens, Zenon Membrane Bioreactors References