DRINKING-WATER TREATMENT BY USING ULTRAFILTRATION HOLLOW-FIBER MEMBRANES

Ultrafiltration of river water for drinking water production was perfo rmed with hollow fiber membranes in a crossflow filtration system with frequent membrane backwashing. The effects of membrane material, oper ating conditions and raw water quality on UF behavior were investigate d. The permeate flux for the hydrophilic cellulose acetate (CA) membra nes was much higher than that of the hydrophobic polyethersulfone (PES ) membrane, a phenomenon which was explained by membrane fouling due t o the adsorption of substances in raw water on and in the pores of the membranes. In order to maintain the high and stable flux for the CA m embrane, the operating backwashing pressure should be more than twice as high as the filtration pressure. It was also shown that efficient r emoval of organic compounds from raw water was accomplished by the fou led CA membrane.