Impact of organic matter on fouling propensity of a new ultrafiltration membrane with low adhesive surface – a study based on 10 different waters

Ultrafiltration (UF) membranes are widely used to treat surface water due to their capacity to remove colloids, particles, pathogens and virus. Today, they are also applied for reverse osmosis pre-treatment of wastewater reuse and desalination in order to address the problem of water shortage. However, membrane fouling by organic matter remains a key issue for membrane application. BASF/Inge has developed a new UF membrane having a low adhesive surface thanks to the superior properties of a new chemistry of the membrane material. Multi-cycle fouling tests were conducted at lab scale to benchmark the performance of this membrane differently functionalized compared with the standard polyethersulfone (PESU) membrane. The impact of organic matter on membrane fouling was investigated using ten different waters, including four surface waters from rivers, dams and lakes, four seawaters from North Sea, Atlantic Ocean and Mediterranean Sea, and two secondary effluents collected at the outlet of municipal wastewater treatment plants. Four key discriminating factors were used in this study: reversible fouling, irreversible fouling, backwash recovery and permeate quality. The waters quality was characterized using global parameters, such as calcium and silica content, turbidity, total suspended solid and algae counts. The organic matter, and especially the biopolymers known to be responsible for membrane fouling, was quantified with liquid chromatography organic carbon detection (LC-OCD). The performances of the new ultrafiltration membrane in terms of fouling propensities and permeate water quality are discussed. The results showed that thanks to its amphiphilic surface resulting in lower adhesive forces, the new membrane was the less prone to foul on 90% of the raw waters compared to the standard PESU membrane.