Combination of nano TiO₂ photocatalytic oxidation with microfiltration (MF) for natural organic matter removal

TiO₂ photocatalytic oxidation was combined with microfiltration (MF) (PCOMF) to remove humic acid (HA) in waters through investigating the flux performance, TOC, UV254 and UV436 removal efficiency, the fouled membrane surfaces by SEM. The results demonstrated that the combined PCOMF process showed a high removal efficiency of UV254 and UV436 of HA (close to 100%). The removal efficiency of TOC was about 84.34% indicating that most of HA was mineralized into water and carbon. The SEM images witnessed that the fouling on the membrane surfaces contaminated by PCO effluents after UV254 and UV365 light irradiation was mainly attributed to cake layer, which was reversible due to the increase of aggregated particles size consisting of HA and TiO₂. Eventually, the combined PCOMF process displayed an improved effect on HA removal and fouling control to a certain level.