Three-dimensional heterogeneous electro-Fenton oxidation of biologically pretreated coal gasification wastewater using sludge derived carbon as catalytic particle electrodes and catalyst

A novel catalytic particle electrode (CPE) was prepared and applied in three-dimensional electro-Fenton (3D EF) for the treatment of biologically pretreated coal gasification wastewater and the performance was compared to that of pure Fe3O4 magnetic nanoparticles (MNPs). The sewage sludge derived activated carbon supported iron oxide (SAC-Fe) was synthesized from sewage sludge and iron sludge via a facile method and served as both CPEs and catalyst in 3D EF. The results revealed that SAC-Fe had higher adsorption capacity and degradation efficiency than Fe3O4 MNPs. 3D EF with the addition of this novel CPE exhibited excellent treatment performance in pollutants and toxicity removal and biodegradability of the treated wastewater was improved remarkably. Based on the measurements of H2O2 and HO*, it was deduced that the enhancement of catalytic activity was responsible for generating more H2O2 and HO*. Meanwhile, the stability and reusability of the CPEs were also evaluated. SAC-Fe was promising to be potentially used as CPEs in 3D EF to remove organic pollutants in wastewater. (C) 2015 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.