Deborah Helstrom, P.E.

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217.158 Membrane Bioreactors Treatment Systems
(MBR)

• Deborah Helstrom, P.E.
• Industrial Permits Team
• Wastewater Permitting Section
• 512-239-6705
• dhelstro_at_tceq.state.tx.us

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Membrane Bioreactors (MBR)

• Combination
• Activated Sludge
• Membrane filtration
• (replaces secondary clarifier)

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Ultrafiltration Membranes
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Ultrafiltration Membranes
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Hollow Fiber Membranes
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Flat Plate Membranes
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Other Configurations
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Membrane Bioreactors (MBR)

• Advantages
• Smaller Footprint
• High Quality Effluent
• Automatic Control
• Less Sludge
• Disadvantages
• Capitol Costs
• Energy Costs for Aeration and Scouring
• Highly Variable Flow require Equalization

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Membrane Bioreactors (MBR)
Expected Performance

• CBOD5 lt5 mg/l
• TSS lt1 mg/l
• Ammonia lt1 mg/l
• Total Nitrogen (w/pre-anoxic zone) lt10 mg/l
• Total Nitrogen (w/pre-anoxic and
• post-anoxic zone) lt3 mg/l
• Total Phosphorus (with chemical addition)
• lt0.2 mg/l (typical) lt0.05 mg/l (achievable)
• Total Phosphorus (with Bio-P removal)
• lt0.5 mg/l
• Turbidity lt0.2 NTU
• Bacteria up to 6 log removal (99.9999)

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Membrane Bioreactors (MBR)

• Currently Compiling Surveys from Vendors of
  Membranes to Develop Design Criteria
• Concerns
• Prevention of Fouling
• Adequate aeration at high MLSS concentrations
• Achievable rate of flow through membranes
• Adequate pretreatment i.e. fine screening
• Hydraulics
• Ensure Integrity
• Foam Control
• Warranty
• Nutrient Removal

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Membrane Bioreactors (MBR)
Results of Survey, Literature and Other State
Regulations

• Membranes
• Nominal Pore Size
• Absolute Pore Size
• Pretreatment
• Fine Screen (Type, Size)
• Primary clarifier, Grit Removal, Oil and Grease
  Removal (When required)

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Membrane Bioreactors (MBR)
Results of Survey, Literature and Other State
Regulations

• Operation
• Gross Flux Rate _at_ 20 C
• Net flux rate _at_ 20 C
• Operational Range for TMP
• Maximum Operational TMP
• Operational Range of MLSS Concentration in Bio
  Reactor
• Operational Range of MLSS Concentration in
  Membrane Tank
• Operational control parameters used and range of
  values
• (Turbidity, SRT, DO, TMP, ORP)
• Amount of air used per square foot of membrane
• Method of Integrity Testing (i.e. Turbidity)
• Method of Foam Control

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Membrane Bioreactors (MBR)
Results of Survey, Literature and Other State
Regulations

• Maintenance clean
• Method
• Frequency
• Chemical clean
• Frequency
• Chemicals used
• Concentrations

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Membrane Bioreactors (MBR)
Results of Survey, Literature and Other State
Regulations

• Redundancy
• N1 or other method
• Peak Flow
• Peak Ratio which requires Equalization
• RAS rate (Q)
• Hydraulics
• Head required for Gravity
• Controls
• Method of backup for controls
• Warranty
• Membranes, other equipment and process

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217.158 Membrane Bioreactors Treatment Systems
(MBR)

• Engineering Report Required
• Common range of values
• Justification for using parameters outside the
  common range
• 2 year performance bond

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Membrane Bioreactors References

• So, You Decided to Build an MBR? Tips to help
  optimize process performance, Merlo, Rion et al,
  WET, www.wef.org/magazine November 2006.
• State of Washington, Department of Ecology,
  Orange Book, Sewage Treatment Design Criteria
• Water Environment Federation, Membrane Systems
  for Wastewater Treatment, 2006
• Manufacturers
• Huber, Koch, Kruger, Kubota, U.S. Filter, Zenon