DOW UltrafiltrationFundamentals, Product Range & Operation
Summary of the Presentation
What is UF/MF? UF/MF Membranes & System Configurations Basic UF/MF Terminology Advantages of UF/MF vs conventional filtration UF Desirable Membrane Properties Specific Features and Benefits of DOWTM UF DOWTM UF UF System Operation & Design Technical Support Applications & References
What is UF/MF?
UF and MF: membrane processes based on size exclusion(physical sieving). Reject particles, colloids, SS, oxidizedFe/Mn, microorganisms...
What UF and MF cannot reject: DOM, Non-Oxidized Fe/Mn,Hardness, Salts.
Ionic Range Molecular Range Macro Molecular Range Micro Particle Range Macro Particle Range
Dissolved Organics
Viruses
Metal Ions
Latex / Emulsions
Bacteria
Colloids
Algae
Giardia
Human Hair
Insecticides
Soluble Salts
Antibiotics
Endotoxins/Pyrogens
Crypto
0.0001
Reverse Osmosis Microfiltration
Nanofiltration
Ultrafiltration
IX
Electrodeionization
0.001 0.01 0.1 1.0 10010
104 106
Micrometers (Log Scale)
Angstrom Units (Log Scale)
Particle Filtration
Technology within Dow Water Solutions
Filtration Spectrum
1 10 100 1000 105
Membrane Configurations
Tubular Plate & Frame
Hollow Fibers
Spiral Wound
UF/MF System Configurations
Pressurized
Hollow fiber modules where water is forced either into or out of the lumen under pressure.
Submerged (or Immersed)
Hollow fiber configurations where water is pulled into the fiber lumen by suction.
There are two basic UF/MF configurations:
PumpFeed
Permeate
Membrane
FeedTank
PumpPermeate
Membrane
UF/MF System Configurations
Pressurized
Hollow fiber modules where water is forced either into or out of the lumen under pressure.
Submerged (or Immersed)
Hollow fiber configurations where water is pulled into the fiber lumen by suction.
There are two basic UF/MF configurations:
Lower footprint and weight Higher and more consistent filtrate quality
(Log-Removal credit regardless water source) Rejects pathogens resistant to chlorination Lower chemical use (polymer, coagulant, pH
adjustment, chlorination,) Easier operation and maintenance (highly
automated operation) Easier expandability Integrated systems (DOW advantage)
Advantages of UF/MF vs Conventional Filtration
.
Some advantages of UF/MF as pretreatment of RO:
Lower fouling in RO membranes.
Reduce chemicalcleaningfrequencies longer life of RO
Posibility to operatethe RO at higherflux LessMembranes & Vessels
Advantages of UF/MF vs Conventional Filtration
.
Some Common UF/MF Terms
Recovery: Ratio of filtrate flow to feed flow [%].
TMP: Transmembrane Pressure (similar to head loss with conventional granular media filters) [bar or psi]
Flux: Permeate Flow Divided by Membrane Area, [lmh or gfd]
Permeability: Normalized flux divided by TMP (sometimes called specific flux) [lmh/bar or gfd/psi]
Fouling: Gradual reduction in filtrate flow at constant pressuredue to adsorption or deposition of contaminants within or onthe membrane.
BW: BackWash (also called Reverse Flush, Backflush, Backpulse)
CIP: Clean In Place (Intensive Cleaning)
CEB: Chemically Enhanced Backwash (other terms: Mini-Clean, Automatic cleaning, Enhanced flux maintenance, Maintenance Clean, Chemical Wash)
AS: Air Scour (or Air Scrub)
Some Common UF/MF Terms
Membrane Properties Are all UF the same?
Pore Size: UF vs MF Fiber Material: Strength, Chemical
Stability, Hydrophilicity Flow configuration: Out-In vs In-Out
.
Membrane Properties UF vs MF UF is a filter of smaller water
pollutants removing pathogens, silt, colloids and medium to higher molecular weight organics. UF obtains higher virus removal than MF.
Flux decline profile more stable for UF (asymmetricmembrane)
0.1 m
0.03 m
.
Membrane Properties Strength Strength of raw polymer - use high
molecular weight PVDF
Strength of porous membrane structure without the use of reinforcing materials
.
Membrane Properties Chemical Stability Polyvinylidene Fluoride (PVDF) Fibers maintain their strength under
continuous harsh chemical cleaning conditions, better than any other membrane material.
Soaking testwith 5000 ppmNaOCl for 250hours
Residual strength of hollow fibers aftersoak in 5000 ppm NaOCl solution
Membrane Properties Hydrophilicity DOW TM UF PVDF Membranes are made hydrophilic higher
resistance to fouling by organics.
PESCA
PAN
PS PVDF
HDPEPP
PTFE
PAN
15
20
25
30
35
40
45
50
55
60
30 40 50 60 70 80 90 100 110 120Contact Angle [Degree, ]
S
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f
a
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T
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DOW UF PVDFDOW UF PVDF
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+ Hydrophilic + Hydrophobic
Flow Configuration: Out-In vs In-Out
Inside / Out
Outside / In
Fiber Material Module LayoutPore Size Flow Pattern
H-PVDF Vertical Encased 0.03 m Out In
UF - A R-PVDF Submerged 0.04 m Out In
UF - B PVDF Vertical Encased 0.04 m Out In
UF - C PVDF Vertical Encased0.1 m (MF) Out In
UF - D PES Vertical Encased 0.025 m In Out
UF - E PES Horizontal Encased 0.025 m In Out
Hollow Fiber UF Manufacturers Comparative
Specific Features and Benefits of
DOWTM UF
.
DOWTM UF Features and Advantages Pressurized Outside/In Modular Membrane Product
Tolerance to wide range of Feed Water quality Simple Vertical Shell Design (no PV needed) Dead-End Operation
1.3 mm x 0.7 mm H-PVDF Hollow Fibers Mechanically strong fibers High Chemical tolerance Treated for Increased Hydrophilicity (high
fouling resistance)
0.03 m Nominal Pore Size Sponge-like structure for high filtration efficiency
.
DOWTM UF Specifications & Operating ConditionsDOWTM UF Model
SFP/SFD -2660
SFP/SFD -2860
SFP/SFD -2880
Module Specifications
Height 1,860 mm 1,820 mm 2,320 mm
Fibers Length 1,500 mm 1,500 mm 2,000 mm
Module Diameter 165 mm (6.5") 225 mm (8.9") 225 mm (8.9")
Module Surface Area 33 m2 51 m2 77 m2
Volume 16 L 35 L 39 L
Weight (water filled) 41 kg 83 kg 100 kg
Shipping Weight 25 kg 48 kg 61 kg
Flow Range 1.3 - 4.0 m3/h 2.0 - 6.1 m3/h 3.1 9.3 m3/h
Fibers Features
Flow Configuration Out to In
Fibers Material Hydrophilic-PVDF
Nominal Pore Size 0.03 m
Operating Conditions
Temperature 1 - 40C
Max. Inlet Pressure Up to 6.3 bar @ 20C; 4.8 bar @ 40C
Max. Operating TMP 2.1 bar
pH, Operating 2-11 (continuous); 1-12 (cleaning)
NaOCl Max. 2,000 ppm
Backwash Flux 100-150 L/m2.h
Feed Requirements
Max. TSS 100 mg/L
Max. Turbidity 300 NTU
Max. Particle Size 300 mSFP-2660 SFP-2860 SFP-2880
.
Filtration(20-60 min)
Air Scrub (20s)Backwash (40-60s)
Forward Flush (30-60s)(Physical Cleaning)
CEB (On-Line); Every 1-7 daysCIP (Off-Line); Every 1-12 months
(Chemical Cleaning)
UF System Operation
Filtration
Ultrafiltrate
Raw WaterFilter
150-200 m
Backwash Tank
Air
Chemicals
Backwash Pump
Feed Pump
Effluent
Air Scour
Ultrafiltrate
Raw WaterFilter
150-200 m
Backwash Tank
Air
Chemicals
Backwash Pump
Feed Pump
Effluent
Air Scour (Drain Step)
Ultrafiltrate
Raw WaterFilter
150-200 m
Backwash Tank
Air
Chemicals
Backwash Pump
Feed Pump
Effluent
Backwash Top
Ultrafiltrate
Raw WaterFilter
150-200 m
Backwash Tank
Air
NaOCl(optional)
Backwash Pump
Feed Pump
Effluent
Backwash Bottom
Ultrafiltrate
Raw WaterFilter
150-200 m
Backwash Tank
Air
Backwash Pump
Feed Pump
Effluent
NaOCl(optional)
Forward Flush
Ultrafiltrate
Raw WaterFilter
150-200 m
Backwash Tank
Air
Chemicals
Backwash Pump
Feed Pump
Effluent
CEB Top
Ultrafiltrate
Raw WaterFilter
150-200 m
Backwash Tank
Air
Chemicals
Backwash Pump
Feed Pump
Effluent
.
CEB Bottom
Ultrafiltrate
Raw WaterFilter
150-200 m
Backwash Tank
Air
Chemicals
Backwash Pump
Feed Pump
Effluent
.
CEB
Acid HCl or H2SO4 @ approx. 500 mg/L (target pH 2) Frequency is typically every 72 hours or when necessary. Removes colloids and inorganic salt plugging both inside and
outside of membrane.
Alkali NaOH @ approx. 500 mg/L (target pH 12) Generally combined with NaOCl @ approx. 350 mg/L Frequency is typically every 24 hours or when necessary. Removes organics and biofoulants from membrane.
CIP
Acid HCl @ 2,000 ppm pH 2
Alkali NaOH @ 1,000 ppm NaOCl @ 2,000 ppm pH 12
Frequency is typically every 1-3 months. Flow rate of 1.5 to 2.0 m3/h/module. Duration is typically 120-150 minutes. Triggered by transmembrane pressure rise.
CIP Solution (up to 40 C)
.
Chemical0.4% HCl 2% Citric Acid
2% Oxalic Acid 0.2% NaOCl 0.1% NaOH
Contaminants
Inorganic Recommended
Organic Recommended Possible
Metal Oxides (Fe,Mn)
Possible Recommended
Colloids / Particles
Recommended
Silica Recommended
Biological Recommended Possible
Coexistence polivalent cations & organic matter
Recommended / 1st CIP
Recommended / 1st CIP
Recommended / 2nd CIP
CIP General Guidelines
.
CEB CIPMaintenance cleaning. Intensive cleaning.
Shorter in duration (but higher frequency). Longer in duration (but lower frequency).
Require less operator involvement. Automatic.
Manually initiated.
It is done with ultrafiltrate. Chemical solution is prepared with demin/RO water, usually at higher concentrations.
Chemical solution is flushed out from thesystem.
Chemical solution is recirculated through thesystem.
Cleaning occurs at ambient temperature. Heating of the cleaning solution isrecommended.
CEB vs CIP
DOW UF Skid
Typical DOWTM UF System
Double Floor DOWTM UF System
Double Floor DOWTM UF System
Design Software - UFlow
10-Page detailed report, including:
System Flow Diagram.
Plant design details (#UF racks, #UF modules per rack, recovery, UF module main features, etc.)
Instantaneous and Average system flows.
Sizing of tanks, valves, piping.
Chemical consumption and cost.
Energy consumption and cost.
Operating Tables.
Design Software - UFlow
Design Guidelines
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Proposal - Engineering Package
Deliverables: P&ID Drawings General Arrangement Drawings Equipment List UFlow Projection
Desired Outcomes:
Value-Add Engineering Assistance to OEM Increase OEM knowledge and comfort with Dow UF product Engage in dialogue for technical questions & further support
DOWTM UF Certificates NSF/ANSI Standard 61
Drinking Water System Components PDWE Certification
USEPA ETV Removal of Microbial Contaminants in Drinking Water
California Surface Water Treatment Rule (SWTR) California Department Public Health
Title 22 Recycle Criteria Drinking Water LRV
o 4-log Removal of Cryptosporidiumo 4-log Removal of Giardia
DOWTM UF References
Globally more than 800 plants running with DOW Ultrafiltration
Over 3,000,000 m3/day UF capacity Global
Over 85 installations more than 7,500 m3/day capacity
Wide range of Applications: Prefiltration before Desalination Surface Water Treatment Waste Water Treatment Process Water Treatment
DOW UF References
Examples of DOWTM UF Systems Al Ain, UAE (Waste Water Reuse UF/RO) Magong, Taiwan (Seawater UF/RO) Tamar Valley, Tasmania (Surface Water UF/RO/IEX) Borsodchem, Hungary (River Water UF/RO) Ataky, Turkey (Secondary Effluent) Moni, Cyprus (Seawater UF/RO) Yanshan Refinery, China (Waste Water UF/RO) Nikolayev, Ukraine (Bore Well Water UF/RO) Gaojing, China (CTBD Reuse UF/RO/EDI) WangTan, China (Seawater UF/RO) Shuozhou Geruite Power Plant Project (Groundwater) Valencia, Spain (Well Water, UF/RO). Soft Drink, Spain (Well Water UF/RO) Mining, Spain (River Water UF/RO) Madagascar (Surface Water UF) Damietta, Egypt (Surface Water, UF+RO) El Shabab, Egypt (Surface Water, UF+2-pass RO)
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Useful Links about DOW UF
DOWTM Ultrafiltration product Overview, Literature & Manuals:
http://www.dowwaterandprocess.com/products/uf/index.htm
Ultrafiltration Product Video and Fiber Repair Video:
http://www.dowwaterandprocess.com/support_training/videos/index.htm
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