Degradation of organic pollutants by an integrated photo-Fenton-like catalysis/immersed membrane separation system

Abstract

To resolve the continuously reuse problem of fine catalysts, a new reactor was investigated by coupling the heterogeneous photo-Fenton-like oxidation with membrane separation. The reactor consisted of a Xe lamp, a submerged membrane module and FeVO4 as catalyst with high activity. Results showed that the catalyst was successfully left in the reactor. It was proved by the kinetics study of membrane fouling that the avoidless membrane fouling was brought mainly by surface cake, at catalyst concentration of 4g/L, it accounted for more than 90% of the total resistance. The kinetics study of catalytic degradation of AO II under sub-critical flux showed the optimal concentration of catalyst was 0.5g/L and under this concentration the membrane fouling was negligible. For a residence time of 60min, the degradation efficiency of AO II reached more than 99% and the chemical oxygen demand (COD) removal efficiency was as high as 91%. The model of continuous stirred tank reactor could predict well for the degradation which was consistent with hydrodynamics study. Moreover, the PFM reactor shows a long-term behavior with both membrane and catalyst in it and merits consideration for scaled-up trials.