Presentation on theme: "Microfiltration / Reverse Osmosis The 1-2 Punch for Water Treatment Presented by: Don Burgess DWG Process Supply Ltd."— Presentation transcript:
Microfiltration / Reverse Osmosis The 1-2 Punch for Water Treatment Presented by: Don Burgess DWG Process Supply Ltd.
CLOTH & DEPTH FILTERS R 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 MEMBRANETYPE RELATIVE SIZE OF COMMON MATERIALS REVERSE OSMOSIS NANO- FILTRATION ULTRAFILTRATION MICROFILTRATION SCREENS & STRAINERS LATEX EMULSIONS METAL IONS VIRUS VOC’S, PCD, SUSP. OIL AQUEOUS SALTS ATOMIC RADII PROTEINS/ENZYMES OIL EMULSIONS PAINT PIGMENT BACTERIA HUMAN HAIR SAND RED BLOOD CELLS CARBON BLACK DISSOLVED ORGANICS PARTICLE SIZE 10 -4 10 -3 10 -2 10 -1 1.0 10 10 2 10 3 (MICRONS) APPROXIMATE 100 200 20,000 500,000 APPROXIMATE 100 200 20,000 500,000 MOLECULAR WT. MOLECULAR WT. PARTICLE SIZE 1 10 100 1,000 10,000 100,000 10 6 10 7 (ANGSTROMS) Cryptosporidium Oocyst Giardia Cyst Material Sizes Source: GE Water
Filtration Processes Microfiltration / Ultrafiltration Removes turbidity Provides barrier to Crypto/Giardia Backwashable “Surface Water” “Spaghetti removes Solids” Reverse Osmosis / Nanofiltration Removes dissolved compounds Typically can not backwash Fouled by turbidity “Ground Water” “Layered removes Liquids”
Nobleford Pilot Raw water 2 to 7 NTU 3 mg/L TOC Treated Water < 0.1 NTU 0 to 1 particles 50% TOC red.
Vernon Pilot Turbidity < 0.1 NTU Particle counts – 0 to 1 Successful operation w/o pretreatment 65% TOC red. w/ pretrtmnt
MF Test Results Site 1Site 2Treated Water Raw Water Turbidity (NTU)1 to 710 to 25<0.02 TOC (mg/L)9 to 1110 to 154 to 6 Colour (TCU)5 to 4023 to 40< 5 Chemical Dosages Alum (mg/L)10075 to 100 PAC (mg/L)1013
MF Membrane Technology Benefits Exceeds Environmental Treatment Standards Consistent treatment quality Modular, Compact and Cost Saving System Configurations Some Membranes Warranted for 10 Years Automatic Integrity Testing On-Line Technical Support and System Diagnosis
RO / Nano filtration Removes dissolved compounds Non-backwashable Max 0.5 to 1 NTU Max SDI = 3.0 “Ground Water” “Layered removes Liquids”
Applications Ground water treatment TDS Hardness Metals such as arsenic GWUI Surface water Organics
Pre-Treatment for Nano/RO Nano / RO Concentrate Pre-Filtration for Solids Removal Pre-Oxidation for Iron/Mg Removal Microfiltration Raw Water SDI < 3 Raw Water Pre- oxidation Filtration Nano / RO Concentrate Permeate
Pre-treatment Required Cartridge Filters (5 micron) Antiscalant (chemical) As Needed Multi Media Filtration (Iron Removal) MF/UF (suspended solids, turbidity)
RO or Nano Reverse Osmosis Low energy membranes provide high efficiency removal Removes 97 to 99% of all dissolved compounds Blend w/ raw water to meet guidelines and restabilize treated water Nanofiltration Removes 60 to 80% of dissolved compounds Use for GWUI as treat entire flow stream “Softening” filter Specially formulated membrane to resist organic (TOC) fouling
Pros and Cons Pros Ease of operation Superior water quality Reduced footprint Membrane elements are standardized Modular units Cons Higher energy costs High waste volumes – 60 to 80% recovery
System Operation Feed water boosted to approx 175 psi to drive flow through membranes Water 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
Summary The 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.