Long-term operation of ultrafiltration membrane in full-scale drinking water treatment plants in China: Characteristics of membrane performance

The installed capacity of ultrafiltration (UF) membranes in drinking water treatment plants (DWTPs) has increased significantly, it is necessary to summarize the long-term characteristics of UF membranes in full-scale DWTPs in China. Firstly, the characteristics of UF membranes applied in large-scale DWTPs in China were systematically evaluated based on capacity, location, membrane materials and filtration mode. By 2020, the total capacity of large-scale DWTPs using UF membranes has reached ~10 million m³/d. Polyvinylidene fluoride was the dominant UF membrane material with a proportion of 73.7 %, followed by polyvinyl chloride. Secondly, the performance of UF membranes in various typical DWTPs during long-term operation was analyzed. UF membrane in five typical treatment processes displayed good contaminant removal performance, while the combination of UF membrane with coagulation, sedimentation and filter was widely used. The fouling evolution of UF membranes during long-term operation was systematically analyzed. Then, the effect of pretreatment methods and cleaning approaches on membrane in full-scale DWTPs were assessed. The use of hydraulic cleaning, maintenance cleaning and recovery cleaning could ensure the stable operation of UF membranes, while these cleaning methods may adversely influence membrane lifetime. This study could provide useful guidance for long-term operation of UF membrane in full-scale DWTPs.