Pilot Study of Ultrafiltration-Nanofiltration Process for the Treatment of Raw Water from Huangpu River in China

Pilot-scale test was carried out to evaluate the performance of a combined ultrafiltration (UF)-nanofiltration (NF) membrane process for the treatment of raw water from Huangpu River, Shanghai, in China. Results showed that UF could significantly remove turbidity, iron and manganese, and also could retain a part of high molecular weight (MW) organic compounds. Subsequently, NF could further reject low MW organics and inorganic salts, and ensured the treated water to reach the Standards for Drinking Water Quality in China. It seemed that 90 L/m2·h was an appropriate permeate flux for UF system when the raw water was directly filtered by UF membrane, the addition of coagulant (alum or ferric chloride) was not preferable to mitigate the fouling of the UF membrane. After near 120 days operation, the permeate flux of NF could be main-tained at 24-25 L/m2·h steadily, and no chemical clean was required.