Pressure driven membrane processes - the answer to the need of a growing world population for quality water supply and waste water disposal

The number and size of membrane based plants for the production of potable water and for the treatment of wastewater are increasing rapidly on our pla net. The processes involved are reverse osmosis/nanofiltration and ultrafil tration/microfiltration. These plants produce clean water within one of the following scenarios: (1) Feed source seawater, supply unlimited, product p otable water, (2) feed source brackish or human-contaminated well water, su pply limited, product potable water; (3) feed source polluted water from ri vers or lakes, supply almost unlimited, product potable water; and (4) feed source waste water, product high quality clean water for farming/gardening or for discharge into rivers/lakes. For these scenarios examples are prese nted which call be considered as 'advanced'. Based on these examples the po tential and the limits of the processes are discussed taking into account a vailability, safety with respect to product quality and costs. (C) 2001 Els evier Science B.V. All rights reserved.