In Situ Utilization of Iron Flocs after Fe³⁺ Coagulation Enhances H₂O₂ Chemical Cleaning to Eliminate Viruses and Mitigate Ultrafiltration Membrane Fouling

Viruses found in the effluent and on the membrane surfaceduringultrafiltration (UF) processes will introduce hidden biosecurity dangersto drinking water. Fe3+ coagulation coupled with H2O2 to create an in situ membrane cleaning method,and MS2 bacteriophage was used as a model to investigate virus removalby UF when humic acid (HA) was present. The results showed that MS2was removed by HA based on size exclusion, hydrophobicity, and electrostaticrepulsion. Meanwhile, HA slightly reduced MS2 accumulation on themembrane surface by inhibiting MS2 adsorption. Fe3+ pretreatment(0.08 mmol/L) eliminated MS2 in the effluent by the adsorption andsize exclusion of iron flocs. MS2 retained on the membrane surfacewas reduced through electrostatic repulsion. Iron flocs-H2O2 cleaning destroyed viral protein capsids through HO & BULL;oxidation and eliminated all MS2. The mitigation efficiency of membranefouling was greatly improved with a flux recovery of 97.8%. Moreover,the use of H2O2 was significantly saved (3%)compared to no Fe3+ pretreatment (12%). This study providesa potentially useful and economically enhanced membrane cleaning methodfor virus-containing water treatment by UF, which could not only eliminateviruses and mitigate membrane fouling in the UF system but also reducethe use of membrane cleaning agents to save costs. Viruses found in the effluent and onthe membrane surfaceduring ultrafiltration (UF) processes will introduce hidden biosecuritydangers to drinking water. Fe3+ coagulation coupled withH(2)O(2) to create an in situ membrane cleaningmethod, and MS2 bacteriophage was used as a model to investigate virusremoval by UF when humic acid was present.