Simultaneous membrane fouling mitigation and emerging pollutant benzophenone-3 removal by electro-peroxone process

Abstract

In this work, the effects of electro-peroxone (E-peroxone, i.e. combination of ozonation and electrolysis using a carbon based cathode) assistance on microfiltration (MF) was systematically investigated from the performance and mechanism viewpoints. Results show that E-peroxone oxidation exhibited better ability than individual processes in membrane fouling mitigation when using bovine serum albumin (BSA), humic acid (HA) and silicon dioxide (SiO2) particles as model foulants. The relative fluxes at 250 s E-peroxone assisted MF treatment were determined to be ~0.30–0.71, which are > 15% higher than those in single ozonation or electrolysis assisted MF process. The efficiency of E-peroxone process in membrane fouling reduction was positively correlated with the applied voltage (0–4 V) and inlet ozone concentration (0–48.6 mg/L). The experimental data combined with three-dimensional excitation-emission matrix fluorescence spectra (3D EEMs) analysis indicate that simultaneous fouling mitigation and emerging pollutant benzophenone-3 (BP3) removal could be obtained during actual river water treatment. Furthermore, the comparison tests reveal that generation of hydroxyl radicals (HO) via enhanced O3/H2O2 decomposition had a significant role on the organic contaminant degradation and membrane fouling mitigation in E-peroxone assisted MF process, and the introduced electrostatic repulsion force could also contribute to the fouling reduction. These observations suggest that E-peroxone maybe a feasible assistive method for membrane filtration water treatment.