Different combined systems with Fenton-like oxidation and ultrafiltration for industrial wastewater treatment

Abstract

Combining Fenton-like oxidation with ultrafiltration by membranes seems promising for wastewater treatment, while it still has defects in comprehensive comparison of different combinations for industrial wastewater treatment. To fill in these gaps, mixed matrix Fe3O4/polyvinylidene fluoride membranes were used for setting up three combined systems, i.e., sequential oxidation and filtration (Seq-O&F), simultaneous oxidation and filtration (Sim-O&F), and sequential filtration and oxidation (Seq-F&O) systems. Performance on industrial wastewater decontamination was evaluated, and anti-fouling property of membranes was measured by flux decline and recovery efficiency. Characterizations of membranes and change of molecular weight distribution were also investigated for auxiliary analysis. Furthermore, the stability of membrane matrix and catalyst was investigated for time-equivalent of 10,000 L/m2 wastewater treatment. The results indicate that Seq-O&F system shows the best decontamination and anti-fouling performance, but with multi-units and low stability of the catalyst. Sim-O&F system shows acceptable decontamination and anti-fouling performance, yet the stability for long-term operation needs to be further improved. Seq-F&O can effectively save the oxidant and prolong operational life, but performs worse in decontamination and anti-fouling. We believe this study gives a new understanding of Fenton-like oxidation and ultrafiltration combined systems for industrial wastewater treatment, and provides guidance for further application.