Interfacial catalytic oxidation for membrane fouling mitigation during algae-laden water filtration: Higher efficiency without algae integrity loss

Membrane fouling remains a significant issue in algae removal during membrane filtration. We constructed an interfacial catalytic oxidation membrane to mitigate membrane fouling caused by microalgae. Specifically, zero-valent iron (ZVI) nanoparticles (NPs) were immobilized on polycarbonate (PC) membrane to activate peroxymonosulfate (PMS). The activated PMS can oxidize extracellular organic matter (EOM) near the membrane surface and result in better filtration performance. The optimal ZVI NPs coated PC membrane with 0.1 mM PMS exhibited excellent anti-fouling property during the filtration of Chlorella v. suspension. The membrane performance can stay stable at least in five algae-laden water filtration cycles by regenerating ZVI NPs. Moreover, the interfacial oxidation only happened on the membrane surface, thereby minimizing algae cell breakage and associated disinfection by-products formation potential (DBPFP) in comparison with traditional in situ pre-oxidation. Indeed, no severe cell breakage was observed with the PMS dosages of less than 0.2 mM. The new interfacial catalytic oxidation strategy proposed here paves a sustainable way to the treatment of algae-laden water.