Basic Design Concepts of MBR

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1 Basic Design Concepts of MBR Class III & Class IV OTCO Workshop Wednesday August 15, 2007 Terry M. Gellner, P.E CT Consultants, Inc

2 Outline Types of Membranes MBR WWTP and General Sizing Criteria Common Terms and Definitions Review of Hollow Fiber and Flat Plate Components What s s on the Horizon

3 Referenced Text Membrane Systems For Wastewater Treatment by Water Environment Federation

4 Referenced WWTP Cauley Creek WWTP Georgia Forsyth WWTP Georgia Savannah WWTP - Georgia Hyrum WWTP Utah Hampton WWTP Georgia Delphos WWTP Ohio Mt Sterling WWTP Kentucky Green Castle WWTP - Indiana

5 Membrane Bioreactor Systems Types of Membranes MBR WWTP and General Sizing Criteria Common Terms and Definitions Review of Hollow Fiber and Flat Plate Components What s s on the Horizon

6 Membrane Classifications Microfiltration (MF) Ultrafiltration (UF) Nonofiltration (NF) Reverse Osmosis (RO)

7 Comparison of Membrane Filtration Processes Comparison of Membrane Filtration Processes Contaminants Rejected MBR Performance

8 General Process Characteristics MF and UF Low Pressure Size Exclusion Pathogenic bacteria and some viruses MBR Systems, polishing and post treatment NF and RO Higher Pressure Size Exclusion plus diffusion charge Pathogenic bacteria, viruses, dissolved solids and ions Secondary polishing and post treatment

9 Typical Types of Membranes Nozzle Membrane Panel Spacer Membrane Sheet Reinforced Structure Biomass Effluent Hollow Fiber Microstructure

10 Membrane Bioreactor Systems Types of Membranes MBR WWTP and General Sizing Criteria Common Terms and Definitions Review of Hollow Fiber and Flat Plate Components What s s on the Horizon

11 MBR? A membrane bioreactor (MBR) is a combination of suspended growth activated sludge biological treatment and membrane filtration equipment performing the critical solids/liquid separation function that is traditionally accomplished using secondary clarifiers and filters.

12 Conventional Activated Sludge

13 MBR Activated Sludge

14 Process Overview Schematic

15 Process Units and Sizing Criteria Preliminary Treatment Screening Grit/Grease Removal Activated Sludge Process Aeration Tank Membrane Bioreactor Biological Nutrient Removal Post Treatment Disinfection Post Aeration

16 Preliminary Treatment Screening Type One Dimensional Bar type (Slotted) Two Dimensional Perforated hole Capture Mode Size 1, 2 or 3 mm Operation

17 Grit and Grease Types observed Vortex Aerated Grit Headcell Partical Size Grease/Scum

18 Activated Sludge Process Permitted Design Criteria Flow Rates Pollutant Loadings CBOD, TSS, TKN, NH3, TP, TN Biological Nutrient Removal Basin Types and Volumes

19 Membrane Bioreactor Sizing Membranes are Hydraulically Restricted Low Flow Average Daily Flow Maximum Daily Sustained Flow Peak Instantaneous Flow Membrane design flow Operating MLSS Concentration Temperature Equalization

20 Post Treatment Disinfection Chemical Ultraviolet Disinfection Open Channel Ultraviolet Disinfection Close Conduit Is disinfection needed? Post Aeration

21 Hyrum WWTP UV Disinfection

22 Savannah WWTP Disinfection

23 Typical Permeate Sample

24 Permeate Quality Water reuse is popular

25 Membrane Bioreactor Systems Types of Membranes MBR WWTP and General Sizing Criteria Common Terms and Definitions Review of Hollow Fiber and Flat Plate Components What s s on the Horizon

26 Gross Flux The volume of water that passes through a membrane per unit time and per unit surface area of the membrane. Flux is often normalized based on temperature. Instantaneous Permeate Flow /Surface Area

27 Net Flux The total Permeated Flow over 24 hours divided by the total surface area expressed in gallons per minute per square foot. Total Permeate Flow/ Surface Area

28 Total Surface Area The total surface area represents the total membrane surface area available for treatment in a membrane system.

29 Transmembrane Pressure The difference between average/concentrate pressure and the permeate pressure is the driving force. The TMP is a means to assess fouling. TMP = feed pressure permeate pressure

30 Fouling The build up of impurities on the membranes such as colloidal materials. Fouling reduces flux through the membrane and increase the TMP. Micro fouling is the build up of impurities in the membrane pores.

31 BioFilm A thin layer of sludge on the membrane. Biofilm occurs on all membranes. Some manufacturers rely on biofilm. Other choose to ignore it.

32 Biohydraulics Term developed by Enviroquip. Bio hydraulics is the interrelationship between the BIO-logical process and the HYDRAULIC characteristics of the membranes.

33 Permeability The permeability of a membrane is the flux rate divided by the transmembrane pressure. P = Flux / TMP

34 Recovery Recovery is the concept of restoring the hydraulic characteristics of the membrane. Recovery is achieve by membrane cleaning.

35 Membrane Bioreactor Systems Types of Membranes MBR WWTP and General Sizing Criteria Common Terms and Definitions Review of Hollow Fiber and Flat Plate Components What s s on the Horizon

36 Membrane System Components Feed Stream, RAS and WAS Air Systems Membranes and Hardware Permeate System Flux Maintenance Systems Integrity Monitoring System Programmable Logic Controller

37 Comparison of Leading Manufacturers Hollow Fiber - Zenon - General Electric Flat Plate - Kubota Enviroquip a subsidiary of Eimco

38 Cauley Creek WWTP - Zenon

39 Cauley Creek WWTP Aeration Tanks

40 Forsyth WWTP - Zenon

41 Forsyth WWTP Fine Screening of RAS

42 Savannah WWTP Aeration Tanks

43 Hollow Fiber Flow Scheme

44 Zenon Membrane Rack

45 Immersed Membrane Train Air Separator Permeate Pump Air Manifold Permeate Manifold Cassette Permeate Header

46 Process Air System

47 Forsyth WWTP Aeration and MBR Blowers

48 Hollow Fiber Membrane Air System

49 Forsyth WWTP Air and Permeate Piping

50 Forsyth WWTP Pneumatic System Compressors

51 Hollow Fiber Permeate System

52 Hollow Fiber Flux Maintenance System Relax Air System with Air Pulsing Backpulse System Chemical Cleaning Backpulsing Maintenance Cleaning Recovery Cleaning

53 Forsyth WWTP Permeate system

54 Cauley Creek WWTP RAS and Backpulse Tank

55 Savannah WWTP Permeate System

56 Savannah WWTP Chemical Feed System

57 Forsyth WWTP Scum Removal System

58 Hollow Fiber Integrity Monitoring System Anoxic and Aeration Dissolve Oxygen Process Air System Flow and Pressure MBR Air System Flow MBR Tank - Level Turbidity Permeate

59 Hyrum WWTP - Kubota

60 Hyrum WWTP

61 Hyrum WWTP MBR Tank

62 Hampton WWTP - Kubota

63 Hampton WWTP

64 Delphos WWTP Membrane Deck

65 Flat Plate Feed Forward Flow Scheme 1

66 Flat Plate Membrane Flow Scheme 2

67 Kubota Flat Plate Membrane

68 The Kubota panel type MBR

69 Process Air System

70 Delphos WWTP Process Aeration

71 Flat Plate Membrane Air System

72 Hyrum WWTP Membrane Air Piping

73 Delphos WWTP Process and MBR Blowers

74 Delphos WWTP Air System and Hardware

75 Flat Plate Permeate System

76 Hyrum WWTP Permeate Piping

77 Hyrum WWTP Anoxic Tanks

78 Delphos WWTP Pipe Gallery

79 Delphos WWTP Permeate Pumps

80 Hampton WWTP Permeate System

81 Flat Plate Flux Maintenance System Relax Air Scour Clean In Place Chemical Cleaning

82 Flat Plate Air Scour Blow Off

83 Hampton WWTP Chemical System

84 Delphos WWTP Chemical System

85 Delphos WWTP Chemical Feed Connections

86 Flat Plate Integrity Monitoring System Anoxic Level and Meter Flow Process Air System Flow and Pressure Air System to MBR - Flow Aeration Dissolve Oxygen and NaDH MBR Tank Level Permeate - Turbidity

87 Turbidity Meters

88 MBR Flow Meter and Valves

89 Programical Logic Controller

90 System Comparisons Hollow Fiber Process Air System MBR Air System Pneumatic System Permeate System Backpulse System Chemical System Tank Drain System Integrity System PLC System Flat Plate System Process Air System MBR Air System Permeate System CIP Chemical System Integrity System PLC Controller

91 Hollow Fiber Summary Relies on pore size of membrane Promotes frequent flux maintenance Uses regular membrane cleaning Promotes support facilities for primary equipment Promotes multitasking of equipment Appears more focused on filtering through membrane

92 Flat Plate Summary Relies on biofilm to aid in filtering Promotes regular flux maintenance Uses less frequent membrane cleaning Minimizes on site equipment Separates equipment uses Focus is on biohydraulics

93 Membrane Design Approach There are more differences than similarities Learn the difference in the technology Visit existing plants with design team Question the membrane suppliers The design is site specific The biology is important Compare equal systems Select the system that suits you

94 Membrane Bioreactor Systems Types of Membranes MBR WWTP and General Sizing Criteria Common Terms and Definitions Review of Hollow Fiber and Flat Plate Components What s s on the Horizon

95 What s s on the Horizon Application of MBRs is expanding Size of plant continues to increase More focus on Headworks Optimizing operations is a point of focus Hollow Fiber is beginning to look more at Biology (TTF & ctoc) WEF has established a COP

96 Questions Terry M. Gellner, P.E. CT Consultants, Inc