TREATMENT FOR PUBLIC SUPPLY IN THE 1990S - A ROLE FOR MEMBRANE TECHNOLOGY

Higher water quality standards and water treatment guidelines are being implemented worldwide. Conventional water treatment cannot secure compliance with all of the new standards. The use of ''advanced water treatment'' options, including ozonation and granular activated carbon stages, improve water quality but add considerably to complexity of operation and to costs, Disinfection by chemical inactivation is also under examination from new standards on by-products, customer complaints of chlorine tastes and its inability to be fully effective against all waterborne pathogens. Membrane technology potentially offers the water industry a Simple one or two step treatment barrier to overcome all these difficulties leading to a safe, aesthetically pleasing water without chemical use. First time, treatment, with optional organics removal for small community water supplies is potentially the most economic and rapidly growing application of membrane technology in the immediate future. One example is the successful introduction of nanofiltration for the Lochgair community public water supply in Scotland during 1992. This is a research and technology demonstration project jointly funded by Strathclyde Water, PWT Worldwide and Thames Water Utilities.