Status after 10 years of operation - overview of UF technology today

Because of intense regulatory activity and recent microbial outbreaks, low- pressure membrane technologies are recognized by the water industry as very attractive processes for producing drinking water. Today, more than 2 mill ions m(3)/d (750 mgd) of drinking water is being produced worldwide using l ow pressure membranes, including microfiltration (MF) and ultrafiltration ( UF). UF technology has been found to exceed current water regulation for tu rbidity, Giardia, and also virus removal. It should be noted that now out o f the low-pressure membrane full-scale plants identified worldwide, UF appl ications represent about 74% of the total installed capacity. Today, UF tec hnology is being used worldwide for treating various water sources. It is r eported that 50% of the Aquasource UF membrane plants have being applied on surface waters, including river, reservoir, and lake source waters. This t echnology has been used in municipal drinking water application for more th an 10 years. It should be noted that the oldest plant (October 1988), Amonc ourt, France is still running with its original Aquasource membrane modules . The expected membrane life of 5 years estimated from laboratory experimen ts has been verified. The technology has now been optimized and is becoming competitive as compared to conventional processes for larger scale plant c apacities. Projects with capacities greater than 100,000 m(3)/d (30 mgd) ar e being implemented. It should be emphasized that due to the rapid developm ent of this fairly new technology, capital and O&M costs of UF membrane tec hnology are still expected to decrease. The different types of treatment co mbination with Aquasource UF can ensure a treated water quality which meet current and future regulations for various source waters (groundwater or su rface water with higher organic content). UF is perfectly suited to clarify ing groundwater, mainly to eliminate particles (suspended solids or micro-o rganisms). For example, coupled with PAC (CRISTAL((R))), UF can be used equ ally well to treat groundwater contaminated by micropollutants such as pest icides or surface water with a high organic matter load. In addition, for s urface water of high organic matter level and with fairly variable quality, a coagulation/ sedimentation step prior to UF should also be considered.