Nanofiltration membrane process for removal of PFOS from drinking water

Perfluorooctane sulfonate (PFOS) as one class of emerging pollutants detected from waters has drew great attention in recent years. How to remove PFOS from surface water and ensuring the security of drinking water for human beings is very important. In this study, HYDRA-core 10 nanofiltration membrane was used to remove PFOS from stimulate water, and the effects of operating pressure, pH, electrolytes, and humic acid on PFOS rejection were investigated. The results showed that the PFOS rejection increased with pH increase. The divalent salts could improve PFOS rejection compared with the monovalent salts, and the PFOS rejection increased with increasing ionic strength of divalent salts. The humic acid addition improved significantly PFOS rejection, and it can reach up to 95.8% in the 1 mmol/L Ca²⁺ existence, but it would also cause membrane fouling and the decline of membrane flux.