The Membrane Treatment

Innovations in the design and use of pressure-driven membranes can help municipalities reach stringent drinking water quality standards. Although membrane processes have been used successfully for many years to desalt brackish water and seawater, new kinds of membrane processes are now capable of treating water for a wide range of other uses. Some of these new, robust processes—such as microfiltration, ultrafiltration, nanofiltration, and reverse osmosis—promise to do a better job meeting our current water treatment goals than such conventional processes as granular media filtration, carbon filtration and disinfection with chlorine. The various methods have proven capable of filtering cryptosporidium, among other water contaminants, and have been so successful in filtering triahalomethanes and haloacetic acids that the EPA is lowering the maximum contaminant level.