Effects of electrolytic oxidation for mitigating ultrafiltration membrane fouling caused by different natural organic matter fractions

Abstract

Membrane fouling is a challenging issue in terms of ultrafiltration application. However, as a novel water treatment technology, the impact of electrocatalytic oxidation on membrane fouling is still debated. Thus, in this study, to overcome this problem, the application of electrocatalytic oxidation pretreatment was evaluated for mitigating membrane fouling by natural organic matter. The influence of natural organic matter (NOM) fractions on the control efficiency was also investigated using humic acid (HA), bovine serum albumin (BSA), and sodium alginate (SA). The performance was examined through normalized flux decline, fouling resistance analysis, EEM fluorescence spectroscopy and the classical membrane fouling model. The results indicate that the electrocatalytic oxidation pretreatment exhibited a remarkable synergistic effect in the reduction of NOM, with a reduction in the DOC of 53% and 55% for HA and SA, respectively. However, the electrocatalytic oxidation pretreatment exhibited limited influence on BSA. The electrocatalytic oxidation pretreatment efficiently reduced both the reversible and irreversible fouling resistances and increased the membrane flux. The fouling mitigation by electrocatalytic oxidation was attributed to the oxidation of organic matter by ˙OH. The experimental results are expected to provide a feasible strategy for electrocatalytic oxidation to mitigate fouling.