Mitigation of ultrafiltration membrane fouling by peroxides activated by powdered activated carbon: Comparison among sodium percarbonate, hydrogen peroxide and peroxymonosulfate

Advanced oxidation technology has been widely studied regarding the degradation of specific organic micropollutants, but relatively few comparative studies have been conducted in the field of membrane fouling mitigation. In this study, powdered activated carbon (PAC) was used to activate sodium percarbonate (SPC), hydrogen peroxide (H₂O₂) and peroxymonosulfate (PMS), and the control efficiency on ultrafiltration (UF) membrane fouling caused by humic acid (HA) and natural surface water was studied. Peroxides activated by PAC exhibited distinct differences in oxidation efficiency on HA, generally showing the trend of SPC < H₂O₂<PMS. The PAC + H₂O₂ and PAC + PMS systems achieved efficient degradation and mineralization of HA, and the removal rates of dissolved organic carbon (DOC) reached 62.60 % and 81.40 %, respectively. PAC + H₂O₂ and PAC + PMS systems effectively reduced reversible HA fouling by 74.40 % and 95.90 %, respectively, and irreversible HA fouling was reduced by 85.20 % and 99.10 %, respectively. PAC + PMS system generated lots of ^•OH and ${\text{SO}}_4^{·-}$ that effectively removed fluorescent organic matter and significantly decomposed organic matter, with organic matter in the range of 3500∼12000 Da decreased by 94.28 %. Finally, for natural surface water, PAC + PMS pretreatment removed 65.80 % of DOC and 75 % of fluorescent organic matter, and it exhibited superior performance in membrane fouling alleviation in comparison with PAC + SPC and PAC + H₂O₂, with reversible and irreversible fouling resistance reduced by 96.13 % and 47.31 %, respectively. This study can provide a basis for the application of peroxides for mitigation of UF membrane fouling.