MBR Applications Include:

Cartwright Consulting Co. www.cartwright-consulting.com United States Office 8324 16th Avenue South Minneapolis, MN 55425-1742 Phone: (952) 854-4911 Fax: (952) 854-6964 [email protected]

European Office President Kennedylaan 94 2343 GT Oegstgeest The Netherlands Phone: 31-71-5154417 Fax: 31-71-5156636

• Residential development projects Single dwellings Housing clusters Apartment buildings/condominiums • Commercial projects • Mining camps and other remote installations • Emergency response • Military installations • Sports facilities • Recreation parks • Schools • Shopping centers • Office parks

An Introduction to Membrane Bi Bioreactor t (MBR) T Technology h l Presented at:

MOWA 2012 Minnesota Onsite Wastewater Convention by Peter S. Cartwright, PE January 30, 2012

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MBR Process

Activated Sludge vs. MBR

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MBR Advantages

MBR Disadvantages • Higher capital cost, primarily resulting from the membrane unit cost

• High-quality effluent, almost free from suspended solids • The ability to disinfect without the need for chemicals • Complete independent control of HRT (Hydraulic Retention Time) and SRT (Sludge Retention Time), which allow more complete reduction of COD, and improved stability of such processes as nitrification • Reduced R d d sludge l d production d ti • Process intensification through high biomass concentrations with MLSS (Mixed Liquor Suspended Solids) over 25,000 mg/L • Ability to treat high strength wastes • More compact systems, resulting in a smaller footprint • Process unaffected by solids settling • Longer retention time for more complete nitrification • Reduction in post treatment disinfection requirements

• Higher operating costs associated with the energy requirements of the air blower and pumps • Operation at high SRTs may increase levels of inorganic chemicals that are harmful to the microbial populations 4

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Membrane Configurations

Membrane Devices

• Plate & Frame • Tubular • Hollow H ll (C (Capillary) ill ) Fib Fiber • Spiral Wound

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Plate & Frame

Tubular

XXXXX XXXXX CXXXX 8 Cartwright Consulting Co.

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Hollow Fiber

Spiral Wound

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Plate & Frame Variables

Hollow Fiber Variables

 Panel size  Panel material  Membrane material  Pore size  Operating pressure  Reliance on biohydraulics  Membrane to panel attachment method

 Fiber diameter  Method used to bundle the strands  Number of strands per bundle  Membrane material  The method in which air is applied to the bundle  Wall thickness

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U-Shaped Bundle

One-End Potted

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Rigid Fiber Bundle

Both Ends Potted

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MBR Membrane Elements Compared

Membrane Materials xxxMaterials of  Construction Polymeric PS PES PAN PE PP PVC PVDF PTFE PVP CA Non‐Polymeric Coated 316LSS Alumina

Microfiltration (MF) & Ultrafiltration (UF) Hollow Fiber

Device Configuration Tubular Plate & Frame Spiral Wound

X X X ─ X ─ X X X X

X X X X X X X ─ X ─

X X X ─ X ─ ─ X ─ ─

X X X ─ ─ ─ ─ ─ ─ ─

a-

─ ─

X X

Titanium Dioxide Silicon Dioxide

─ ─

X X

─ X ─ ─

─ ─

PS = Polysulfone

PVDF = Polyvinylidene Fluoride

PES = Polyethersulfone

PTFE = Polytetrafluoroethylene

PE = Polyethylene

Parameter Packing Density * Fouling Resistance Energy Requirement Backwashable Cleaning Ease 2 Net Flux Range (L/m /hr) MLSS (mg/L)

─ ─

Membrane Element Configuration Plate & Frame

Hollow Fiber

Tubular

Moderate Moderate Moderate No Moderate 15-25 10,000-15,000

High Moderate Low Yes Moderate 20-30 10,000-15,000

Low High High Yes Easy 70-200 10,000-30,000

* Membrane area per total element volume

CA = Cellulose Acetate

PP = Polypropylene

PVP = Polyvinylpyrrolidone

PAN = Polyacrylonitrile

TF = Thin Film Composite

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Immersed Application xxx

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External Application xxx

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Immersed and External Designs Compared Parameters Aeration Cost Pumping Cost Membrane Flux Cleaning Frequency Total Operating Cost Total Capital Cost

Immersed High Low Low Low Low High

External Low High High High High Low

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MBR System Components

MBR Schematic

• Fine screen (1-3 mm openings) • Membrane cassettes containing elements • Bioremediation tank(s) • Permeate or feed pump • Blowers with diffusers • CIP (clean-in-place) system • Backwashing/Backpulsing equipment

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Membrane Fouling

Foulants Municipal

Industrial

Hair Fibers Plastics Rags Chemicals Other

FOG Chemicals Other

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Anti-Fouling Strategies

Chemical Cleanings

• Relaxing • Backwashing • Backpulsing B k l i – Air/Permeate Ai /P t • Chemicals

• Enhanced Backwash (daily) • Maintenance Cleaning (weekly) • Intensive I t i Cleaning Cl i (1-2x/year) (1 2 / )

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MBR Cleaning Chemicals

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Conclusions  MBR is a proven technology p costs g going g down  Capital  Provides direct reuse  Provides excellent pretreatment  Smaller footprint (land conservation) 34 Cartwright Consulting Co.

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