Pilot study on drinking water advanced treatment by GAC-MF system

The pilot performance of the combined GAC-MF membrane process for drinking water advanced treatment was described. In the process of GAC adsorption, under the conditions of 20 min hydraulic retention time (HRT) and 6 m/h filtration rate, the removal efficiencies of UV254 and trichloromethane could reach 40% and 50% respectively and the UV₂₅₄ and trichloromethane in system effluent was less than 0.015 cm^-1 and 5 μg/L respectively. In the post MF membrane process, MF membrane effectively retained the particles and bacteria in raw water. The effluent turbidity was less than 0.2 NTU and no bacteria were detected at all in permeate. A computer-controlled system was employed to control this system. The membrane operating parameters of backwash interval, duration and flux were studied. The backwash interval of 10-min, 20-min and 60-min was researched respectively, and the variation of trans-membrane pressure was analyzed. Consequently short backwash interval was recommended under the same water consume.