Purchase membrane filtration devices from Tisch Scientific here but first be informed. Expert advise and samples available. Water utilities nationwide are turning to advanced membrane filtration to meet more stringent federal drinking water regulations in order to remove turbidity, precursors, and disinfectant tolerant micro-organisms from both groundwater and surface water supplies.
Low pressure microfiltration (MF) and ultrafiltration (UF) membrane filtration echnology have emerged as viable options for addressing the current and future drinking water regulations related to the treatment of surfacewater, groundwater under the influence, and water reuse applications for microbial and turbidity removal.
Membrane filters
Full-scale facilities have demonstrated the efficient performance of both MF and UF as feasible treatment alternatives to conventional granular media processes. Both MF and UF have been shown to exceed the removal efficiencies identified in the Surface Water Treatment Rule and related rules, such as Cryptosporidium oocyst, Giardia cyst, and turbidity.
MF and UF membrane systems generally use hollow fibers that can be operated in the outside-in or inside-out direction of flow. Pressure (5 to 35 psi) or vacuum (-3 to -12 psi for outside-in membranes only) can be used as the driving force across the membrane. Typical flux (rate of finished water permeate per unit membrane surface area) at 20 degrees C for MF and UF ranges between 50 and 100 gallons per square foot per day (gfd). Since both processes have relatively small membrane pore sizes, membrane fouling, caused by the deposition of organic and inorganic compounds on the membrane, may occur at unacceptable levels if the system is not properly selected, designed, and operated.
Automated periodic backwashing and chemical washing processes are used to maintain the rate of membrane fouling within acceptable limits. Chemical cleaning is employed once a maximum transmembrane pressure differential has been reached. Some systems utilize air/liquid backwash. Typical cleaning agents utilized include acids, caustic, surfactants, enzymes, and certain oxidants, depending upon membrane material and foulants encountered. Chemicals used for cleaning, and the method used in the cleaning process, must be acceptable to the membrane manufacturer.