Water Planet / UCLA,
Keywords: microfiltration, ultrafiltration, membranes, filtration
Summary:Over the past two decades, membrane filtration has proliferated globally to become the gold standard for removing pathogens, suspended solids, emulsified oils and colloids from virtually every type of water source – traditional and non-traditional, fresh and saline. Hence, everywhere nanofiltration (NF) and reverse osmosis (RO) membranes are used – and – anywhere filtration or clarification is required microfiltration (MF) and ultrafiltration (UF) membranes are now frequently used as either treatment or NF/RO pre-treatment. Globally, about 90% of membrane installations for municipal water and wastewater utilize polymeric hollow fiber membranes (with some exceptions, but) predominantly made from either poly(ethersulfone), PES, or poly(vinylidene fluoride), PVDF. Generally, ceramic modules cost 5-10X more per unit area of membrane than polymeric modules, and because ceramic system wetted parts are typically constructed from stainless or higher grade steel (pumps, vessels, header/footer pipes, valves, etc.) system costs are about 3-5X more than polymer membrane systems. However, ceramic membranes are more fouling tolerant, thermally and chemically stable, clean up easier and last longer than polymerics, so there are new scenarios emerging where overall life cycle costs may be comparable for polymerics and ceramics. This talk will begin with a review of state-of-the-art and emerging MF/UF technologies followed by presentation of performance data from two MF/UF pilot studies on: (1) municipal wastewater and (2) industrial wastewater. The presentation will conclude by tying together the impacts of influent water quality and membrane properties on water recovery, energy demand, capital costs and operating costs.