Presentation on theme: "Microfiltration / Reverse Osmosis The 1-2 Punch for Water Treatment"— Presentation transcript:
1Microfiltration / Reverse Osmosis The 1-2 Punch for Water Treatment Presented by:Don BurgessDWG Process Supply Ltd.
2R A N G E S O F F I L T R A T I O N P R O C E S S E S Material SizesR A N G E S O F F I L T R A T I O N P R O C E S S E SCLOTH & DEPTH FILTERSMICROFILTRATIONMEMBRANETYPEULTRAFILTRATIONSCREENS & STRAINERSNANO-FILTRATIONREVERSEOSMOSISLATEX EMULSIONSMETAL IONSRED BLOODCELLSOIL EMULSIONSHUMANHAIRRELATIVE SIZEOF COMMONMATERIALSVOC’S, PCD, SUSP. OILVIRUSDISSOLVED ORGANICSPAINT PIGMENTAQUEOUSSALTSCARBONBLACKBACTERIASANDATOMICRADIIGiardia CystCryptosporidium OocystPROTEINS/ENZYMESPARTICLE SIZE(MICRONS)PARTICLE SIZE , , ,(ANGSTROMS)APPROXIMATE , ,000MOLECULAR WT.Source: GE Water
3Filtration Processes Microfiltration / Ultrafiltration Removes turbidityProvides barrier to Crypto/GiardiaBackwashable“Surface Water”“Spaghetti removes Solids”Reverse Osmosis / NanofiltrationRemoves dissolved compoundsTypically can not backwashFouled by turbidity“Ground Water”“Layered removes Liquids”
5How Small is Small? Membrane Pore Sizes – 0.01 to 0.2 micron Pencil Dot (40 µm)Large SiliceousParticle (20 µm)E-Coli(.45 µm)Giardia Cyst( µm)CryptosporidiumOocyst (2 - 5 µm)[Anthrax Spore]Typical Bacterium (0.2 µm)Membrane Pore Sizes – 0.01 to 0.2 micron
6Why Microfiltration?Turbidity and Microbiology removal with no chemistryTurbidity < 0.1 NTU0.02 to 0.04 NTUCryptosporidium > % RemovalGiardia > % RemovalTOC / Colour removalChemical precipitationCoagulation with Alum / acid / PACRemoval of precipitate with membrane
18Nobleford Pilot Raw water 2 to 7 NTU 3 mg/L TOC Treated Water 0 to 1 particles50% TOC red.
19Vernon Pilot Turbidity < 0.1 NTU Particle counts – 0 to 1 Successful operation w/o pretreatment65% TOC red. w/ pretrtmnt
20MF Test Results Site 1 Site 2 Treated Water Raw Water Turbidity (NTU) 1 to 710 to 25<0.02TOC (mg/L)9 to 1110 to 154 to 6Colour (TCU)5 to 4023 to 40< 5Chemical DosagesAlum (mg/L)10075 to 100PAC (mg/L)1013
21MF Membrane Technology Benefits Exceeds Environmental Treatment StandardsConsistent treatment qualityModular, Compact and Cost Saving System ConfigurationsSome Membranes Warranted for 10 YearsAutomatic Integrity TestingOn-Line Technical Support and System Diagnosis
27Post-Treatment Required pH adjustment (caustic, lime) Disinfection As NeededDegasifier
28RO or Nano Reverse Osmosis Low energy membranes provide high efficiency removalRemoves 97 to 99% of all dissolved compoundsBlend w/ raw water to meet guidelines and restabilize treated waterNanofiltrationRemoves 60 to 80% of dissolved compoundsUse for GWUI as treat entire flow stream“Softening” filterSpecially formulated membrane to resist organic (TOC) fouling
29Pros and Cons Pros Ease of operation Superior water quality Reduced footprintMembrane elements are standardized Modular unitsConsHigher energy costsHigh waste volumes – 60 to 80% recovery
30System OperationFeed water boosted to approx 175 psi to drive flow through membranesWater is clarified as it passes through membrane to produce “permeate”Rejected compounds are concentrated in waste water referred to as “concentrate”Run at one flow rate – “On/Off” operation
40Remember Microfiltration / Ultrafiltration RO / Nano “Surface Water” Turbidity and particle removalCrypto/Giardia barrierBackwashable“Spaghetti removes Solids”RO / Nano“Ground Water”Dissolved compound reductionDo not even think of backwashing“Layered removes Liquids”
41Contaminants Surface Water Turbidity Crypto/Giardia Iron/Mang/Arsenic OrganicsHardnessGround WaterTDSHardnessIron/Mang/ArsenicOrganicsTurbidity
42Treatment Options Contaminant Conventional Process Membrane Process TurbidityFloc/Coag/Clarifier /FilterMFCrypto/GiardiaIron/Mang/ArsenicChem Precip / Mang GreensandChem Precip and MF or ROHardnessLime softng/Recarb / FilterROOrganicsOxidation and GACTDSNot readily available
43System AssessmentLook at compounds that are process dependant, and then add other processes as required for remaining compounds
44Surface Water Contaminant Membrane Process Turbidity MF Crypto/Giardia Iron/Mang/ArsenicMF + Chem PrecipHardnessMF + ROOrganicsMF + Enh Coag, or RO
45Ground Water Contaminant Membrane Process TDS RO Iron/Mang/Arsenic RO or Chem Precip +MFHardnessOrganicsTurbidityMFGUDI
513. MF-NF for Turb, Organics, Hardness Process FlowRiver waterRaw water pondMicrofiltration for turbidity reduction and crypto / giardia barrierNanofiltration for organics / hardness reduction
52Results - MF to NF Parameter Raw Water MF Perm NF Perm TOC (mg/L) 15.8 12.4<0.1Turbidity (NTU)0.860.02Manganese (mg/L)0.005<0.002TDS751749<5Hardness (mg/L)5275301.0
53SummaryThe 1-2 Punch of MF / RO’s, can treat most common contaminants in water.Reduced number of processes, generally results in smaller footprint.Effluent quality from membrane treatment is consistent.