Advanced treatment of coal chemical industry wastewater by electro-catalysis with Gd-Doped Ti/SnO2 anode

Abstract

The preparation of a Gd-doped Ti/SnO2 anode using the sol-gel method was employed in electrolysis as an advanced treatment of coal chemical industry wastewater. The optimal Gd-doped content and sintering temperature were 2% and 750ºC. The electro-catalytic performance was enhanced after doping with an adequate amount of Gd. The doped Gd accelerated the generation rate and content of hydroxyl radicals in the electrolysis process. Gd was mixed into the SnO2 lattice by means of displacement to refine the SnO2 crystalline grain. The diminution of grain size supplied more active sites on the electrode surface. The reaction of TOC degradation was between pseudo zero-order and first-order kinetics, and was more inclined to pseudo first-order kinetics. The performance and the stability test demonstrated that the prepared Ti/Gd-SnO2 anode was competent and that electrolysis with the anode could serve as a technically feasible method with potential application for the advanced treatment of coal chemical industry wastewater.