Membrane Filtration Application from Inside to Outside

Membrane Filtration Application from Inside to Outside Martin Gravel, P.Eng. Senior Water Treatment Engineer CH2M HILL Canada NEWFOUNDLAND DESIGN ASSOCIATES LIMITED Clean and Safe Drinking Water Workshop Water Treatment Alternatives March, 2002 Gander, NF

Presentation Topics What membrane processes are relevant? What is their development history and growth in water treatment? What are the drivers for their application? How are they applied now and in the future? (focus on MF/UF) What are typical costs? Questions

Time is on my side. - Rolling Stones Time has indeed been a friend New chemical-free systems are now available for treating drinking water Membranes are leading the way

Process and Characteristics

PD processes use pressure to separate contaminants from water Feed Water Purified stream (permeate or filtrate) Contaminant- laden stream (continuous or intermittent) Feed Pump Permeate Pump

Separation is achieved either by dead-end end or cross-flow filtration Feedwater Direct (Dead-end) Filtration (typical of MF and some UF) Filtrate Filtrate Recycle Feedwater Cross-flow Filtration (typical of some UF, NF and RO) Filtrate Waste

Degree of contaminant separation is direct function of membrane pore size 0.001µ 0.01µ 0.1µ 1.0µ 10µ 100µ 1000µ Dissolved Organics Sand Salts Viruses Colloids Bacteria Cysts Media Filtration Microfiltration Ultrafiltration Nanofiltration Reverse Osmosis

Water 0.0002 microns. Na Ion 0.00037 microns Influenza Virus 0.1 microns Bacteria 0.28 microns Giardia/ Crypto 3-18 microns Hemoglobin 0.007 microns Reverse Osmosis Nano Ultra Micro Sand 0.0001 0.001 0.01 0.1 1.0 10 100 Pore Diameter - microns

Separation of ions requires greater pressure than separation of particles 1200 1000 800 psi 600 400 200 0 Seawater RO Brackish RO Low Pressure RO NF UF MF

History and Growth

Commercial Timeline of Membrane Processes First ED plant First brackish RO plant First seawater RO plant First NF plant First MF plant First UF plant 1960 1965 1970 1975 1980 1985 1990 1995 2000 Note: plant capacity 1 mgd or greater

(Adapted from Wangnick, 1994) RO and NF growth 200 175 150 Legend RO&NF NF Installed Capacity (mgd) 125 100 75 50 25 0 72 74 75 77 79 80 84 88 91 93 Year

MF & UF growth is increasing rapidly 250 Cumulative Capacity (mgd) 200 150 100 50 MF + UF UF MF 0 1991 1992 1993 1994 1995 1996 1997 1998 1999

MF/UF plant capacity is also steadily increasing 90 80 Plant Capacity (mgd) 70 60 50 40 30 20 10 0 1988 1990 1992 1994 1996 1998 2000 2002 2004 Calendar Year

Why the increased growth in membranes? Capability to address increasing number and more stringent drinking water regulations Public and utility sensitivity to the risk of microbial outbreaks (e.g., Cryptosporidium) Decreased equipment and operating costs Reduced footprint Increasing use of lower quality water sources

Membrane processes can address a wide range of contaminants Application MF UF Process BW NF RO SW RO ED TDS Reduction (brackish/seawater) Specific Ion Removal (NO 3, F, As) Hardness Removal TOC, DBP Precursor Removal Particle Removal Turbidity, Bacteria, Protozoan Cysts Viruses Legend: Excellent Good Fair Poor None

MF/UF treatment meets SWTR/ESWTR requirements while minimizing disinfection Provides superior particle removal filtrate turbidity <0.1 NTU particle counts <5/mL >5 log removal of Giardia, Cryptosporidium and bacteria (MF and UF) >5 log removal of viruses (UF) Free chlorine CT for full or partial virus inactivation is low, minimizing DBPs MF/UF for SWTR/ESWTR compliance is established and fastest growing market segment

Pressure Driven Membrane and Module Characteristics

RO and NF use flat sheet non-porous membranes of cellulosic or polyamide polymers Contaminant rejecting layer (polyamide) Support layer (polysulfone)

Membrane sheets are assembled into spiral wound modules

Modules are series arranged in pressure vessels Feed Flow Seal Concentrate Permeate Permeate Collection Tube Coupling Pressure Vessel

Components of a RO/NF Plant Surface Water Groundwater Chemical Conditioning Clarification* Cartridge Filtration Feedwater Pumping Concentrate (To Disposal) Permeate * Conventional Treatment Direct Filtration In-Line Coagulation MF/UF Raw Water Bypass (if applicable) Off-gas Air Distribution Storage Chemical Stabilization Chlorination Degasification (certain groundwaters)

Loading 8 x 40 Spiral-Wound Membrane Elements in Pressure Vessels

Pressure vessels are arranged into skids or trains

PCI Tubular NF Module

PCI Tubular NF Module in Racks and Skids

PCI Tubular - Fyne Process at Middle River, B.C.

PCI Tubular - Fyne Process at Chapel Island, N.S.

MF/UF use porous hollow fiber membranes of various materials Koch Romicon polysulfone UF fiber (single skinned) Pall Microza polyacrylonitrile UF fiber (double-skinned)

Hollow fibers are configured into pressurized or vacuum-operated modules USF Memcor M10C module Zenon ZeeWeed ZW500 module

Modules are manifolded to form skids or trains 5 Trains of Memcor 90 M10C pressurized modules Single cassette of 8 ZeeWeed ZW500 immersed modules

Components of a Pressure MF/UF Plant Air System B/W Water Cl 2 Raw Water Source Supply Pump Particle Strainer From Modules Membrane Modules Backwash Water Finished Water Storage Distribution Finished Water Pumping CIP System To Disposal or Reuse

There are some important differences in MF/UF and RO/NF systems RO/NF use generic system designs and similar performing membrane modules from multiple manufacturers MF/UF use proprietary system designs and proprietary membrane modules for each system

What are the MF/UF Products? U.S. Aquasource Koch Zenon Pall Filter/Memcor (ZeeWeed) (Microza) Configuration Pressure Pressure Pressure Immersed Pressure Type MF UF UF Quasi UF MF Composition PP CA/PS PS N/A PVDF Pore Size 0.2 µ 0.01µ 0.01µ 0.035 µ 0.1 µ 100KD 100K D Flow Direction Outside-in Inside-out Inside-out Outside-in Outside-in Operation Mode Dead-end Cross-flow Cross-flow Quasi Quasi Cross-flow Dead-end TMP (psi) 3 15 5 30 10 30 1 7 5 25 Oxidant Tolerance None Limited Good Good Good

UF The MF/UF field is continually expanding... Hydranautics HydraCap Leopold Ultrabar Ultrabar Norit XIGA Zenon ZW-1000 MF USF Memcor CMF-S immersed, inside out, dead-end end MF product targeting large capacity plants at reduced cost (<$0.25/gpd equipment cost)

Membrane Pilot World Case Study: Parry Sound WTP

Parry Sound WTP Project History EA originally proposed conventional treatment plant Affordable membrane technologies emerged Pilot Study in 1999 Designed as ultrafiltration plant in 1999 Commissioned May 2001 Plant Size 10 ML/d

Pall stress test samples Raw Water 40 TCU ACH=30 mg/l Permeate Reverse Flow Reverse Flow w/air Scour

Parry Sound WTP (Conceptual Site Rendering) Raw water source - eastern Lake Huron

Parry Sound WTP (Under Construction in 2000)

Parry Sound WTP (Start-Up in 2001)

Parry Sound WTP (Start-Up in 2001)

Parry Sound WTP (Start-Up in 2001)

Parry Sound WTP (Start-Up in 2001)

An Architectural Challenge Case Study: Fairfield WTP

Fairfield WTP Project History Conventional Treatment Plant proposed in early 90 s deemed too expensive - project shelved Study in early 1997 concluded microfiltration plant at old pumping station site affordable Summer 1997 pilot study (Memcor( vs. Zenon) Designed 1998, Construction began Fall 1998 Commissioned May 2000

Fairfield WTP - Stealth Architecture

Aerial View - Fairfield WTP

Fairfield WTP Process Flow Diagram

Fairfield WTP Layout Diagram

The Future is Now Case Study: Sudbury WTP

Existing treatment system is unfiltered, fluoride, lime, chlorine Manganese problems summer 2000 ( black water in distribution system) Quick solution needed!

Typical conventional treatment train Too big to fit on existing site for 40 ML/d capacity

Primary Membranes Zenon 1000 s Secondary Membranes Zenon 500c s Secondary Disinfection Trojan UV Swift

Smaller, Cheaper, Better Sudbury WTP s membrane design uses a siphon as the driving force (cheaper energy, less equipment) Primary and Secondary Membranes achieve >99% raw water recovery High Lift pumps match plant flow Footprint size compared to conventional is much smaller allowing use of existing site

Costs

Installed Membrane Filtration Equipment Unit Costs 2.0 Unit Cost ($/1,000 gals) 1.5 1.0 0.5 AWWARF Cost Curve Actual Bid Costs 0 0.1 1 10 100 Capacity (mgd)

Membrane Filtration Treatment Unit Costs 3.0 Unit Cost ($/1,000 gals) 2.5 2.0 1.5 1.0 MF (AWWARF) UF (AWWARF) MF/UF (actual) 0.5 0 0.1 1 10 100 Plant Capacity (mgd)

MF/UF O&M Cost Breakdown Chemicals (10%) Power (8%) Membrane Replacement (37%) Labor (37%) Total cost = $0.10/kgals produced

MF/UF equipment costs have decreased significantly Equipment Cost [$/gallon] $1.0 $0.9 $0.8 $0.7 $0.6 $0.5 $0.4 $0.3 $0.2 $0.1 $0.0 Costs for 5-mgd capacity 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999

Decreased costs reflect Increasing competition (2 suppliers in 1992; >6 suppliers in 2002) Decreased membrane manufacturing costs (more production installed to meet greater demand) Decreased module/system costs (more membrane area per module)

Where is membrane treatment headed? Installation of Bigger Plants Up to 100 mgd under design in US for MF/UF Increased use of immersed and larger pressurized modules to reduce system cost/complexity Increasing use of pre-clarification to reduce MF/UF plant costs Integration of MF/UF with chemical treatment to address full range of water quality issues coagulation/pac/pre-oxidation oxidation for control of DBPs,, T&O and Fe/Mn Increasing use of NF for DBP reduction/colour colour removal

MF/UF Particle Removal Plant Raw Water Screening MF/UF Chemical Disinfection To Distribution (Cl 2 for virus inactivation) Backwash Water This approach does not address: - control of aesthetic contaminants (taste and odor, iron and manganese) - reduction in DBPs where free chlorine used for secondary disinfection

How do we address more comprehensive treatment requirements? (integrated treatment) Surface Supply Coag-Floc MF/UF Disinfection Coagulant Oxidant PAC Flocculation - MF/UF Coag/Floc/Sed MF/UF Disinfection Coagulant Oxidant PAC Clarification - MF/UF MF/UF NF Disinfection Dual Membranes

Membrane Filtration Application from Inside to Outside QUESTIONS? Martin Gravel, P.Eng. Senior Water Treatment Engineer CH2M HILL Canada NEWFOUNDLAND DESIGN ASSOCIATES LIMITED Clean and Safe Drinking Water Workshop Water Treatment Alternatives March, 2002 Gander, NF