Effect of the composition of PVDF-NIPAM-GO membrane for the removal of organic contaminant and anti-fouling from biofilter effluent under the responsible temperature

Polyvinylidene fluoride (PVDF)-N-isopropylacrylamide (NIPAM)-Graphene oxide (GO) (PNG) membrane can dramatically change their microstructure and performance in response to temperature variations in raw water. However, the research on the effect of responsible temperature and individual component in this membrane is lack of clarity. In this study, the permeability-selectivity index was established to determine the responsible temperature of the PNG membrane at 35 °C (PNG-35). And the biofilter effluent from Beijing wastewater reclamation treatment plant was used to investigate the contribution of each composition in the PNG membrane. It can be noticed that with the addition of GO could increase the permeability 23.33 %，while selectivity increased 15.05 %. After the further introduction of NIPAM, subsequently the permeability could increase 82.86 % with the selectivity increased 11.35 %. Finally, comparing the effluent of membrane by EEM, molecular weight distribution and FTICR-MS, the results showed that the humic-like substances were the main contaminants with molecular weights of 142 Da, 397 Da, and 1147 Da, characterized by their sulfur content, hydrophilicity, and negative charged. Humic-like substances were the main contaminants which the sequence of removal was PNG-35 > PNG > PG > PVDF. Apparently, the adding of GO, NIPAM and the responsible temperature could improve the removal of humic-like substances that attributed to the R ir decreased the value at 0.201, 0.092 and 0.041. And charge effects between the contaminants and membrane surface played a significant role under the responsible temperature.