October 23, 2012

Weathering The Storm: Treating High I/I Flows With Parallel MBR and Conventional Systems

Jason Diamond, P.Eng.

GE – ZENON Membrane Solutions

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Presentation Outline

  Acknowledgements

  Membrane Bioreactors (MBRs)

  Tri-City WPCP MBR

  January 2012

  Ammonia Removal

  Questions

Acknowledgements

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Co-Authors

Michael Trent WES - Clackamas County

Dale Richwine

Richwine Environmental, Inc.

Membrane Bioreactors (MBRs)

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Membrane Bioreactor (MBR)

Activated Sludge Process

Membrane Filtration

MBR

Stable Biological Treatment Process

Absolute Solids Separation

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Membranes are all around us

Synthetic membranes can

remove harmful bacteria and pathogens from

drinking water sources

Natural membranes can be found in living organisms such as human cells. They allow nutrients to enter while rejecting toxins and other waste products

Synthetic membranes can be made from polymer, ceramics and other porous material. They are used for a wide variety of filtration applications.

Tri-City MBR membranes are hollow fibers of porous polymer with billions of microscopic pores on the surface

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How do Membranes Work?

Contaminants such as bacteria and viruses can not pass through the membrane’s pores

Water molecules and dissolved salts pass freely through the membrane pores

Semi permeable membrane wall with microscopic pores

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Membrane Configurations

Spiral wound/tubular: best suited to NF/RO

Hollow fiber: best suited for MF/UF

Sand filtration

Microfiltration

Ultrafiltration

Nanofiltration

Reverse Osmosis

0.0001 0.001 0.01 0.1 1 10 100um

Flat plate

Reverse Osmosis

Tri-City MBR membrane range

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The MBR System

Fiber

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MBR System Overview

Distribution Channel

Membrane Aeration

Filtrate Pumping Mixed Liquor Recirculation Bioreactor

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Membrane Cassette

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MBR Train

Air blower

Filtrate pump

Membrane cassettes

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Process Advantages

Highly aerobic process •  Build community friendly plants with nearby residences

and recreational paths

Operational reliability

•  Performance is independent of sludge settling characteristics. Year round nitrification is ensured.

Reduces sludge yield

•  High SRT operation is possible

Ideal for staged expansion

•  Modular design approach, selected loading parameters (MLSS) and hydraulic capacity (membrane area)

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•  BOD < 3 mg/L (typically non-detectable)

•  TSS < 3 mg/L (typically non-detectable)

•  NH3-N < 0.5 mg/L

•  TP < 0.05 mg/L (requires coagulant addition)

•  TN < 3 mg/L (may require supplemental carbon)

•  Turbidity < 0.2 NTU

MBR Effluent Quality

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The Usual MBR Environment

A B C D

A – Raw Sewage B – Aeration Tank C – Membrane Tank D – MBR Permeate

Tri-City WPCP MBR Expansion

Bioreactor Membrane Trains

Effluent to Discharge

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Tri-City WPCP

Oregon City, OR Map courtesy of www.mapquest.com

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Tri-City WPCP

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Tri-City WPCP MBR Expansion

The MBR portion has a design capacity of 4.0 MGD annual average flow

•  Site planning allows for future expansion of MBR capacity to 24.0 MGD

•  ‘Stepped Expansion’ to provide both additional treatment capacity and additional reuse water supply on an as-needed basis

•  Increases treatment capacity of WPCP while adding a sustainable supply of high quality effluent

•  Energy efficiency and system sustainability given high level of consideration in project decisions:

•  Equipment selection

•  Site design and construction – green roofs, pervious pavement, bioswales, green streets and stormwater retention

•  Educational opportunities

Tri-City WPCP MBR

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Tri-City WPCP MBR - Objectives

Develop an innovative and compact MBR system by minimizing plant footprint

Meet stringent reuse water quality and increase capacity

Achieve cost-effective and reliable solutions efficiently and sustainably

Include planning for future expansions