Catalytic Wet Air Oxidation Using Supported Pt and Ru Catalysts for Treatment of Distillery Wastewater (Cognac and Sugarcane Vinasses)

Abstract

The production of brandy from wine and bioethanol from sugarcane in distilleries generates vinasses, which are effluents that are rich in organic matter. Since they have a high pollution load characterized by high chemical and biological oxygen demands and a dark color, the depollution of these effluents is inevitable. Pt and Ru catalysts supported on titania and zirconia were explored in the catalytic wet air oxidation (CWAO) processing of cognac and sugarcane wastewaters, in batch mode and in a trickle-bed reactor, at a temperature condition of 190 °C and a pressure condition of 70 bar air. The addition of a catalyst promoted total organic carbon (TOC) abatement and the oxidation of ammonium ions formed from organic nitrogen in the effluents to dinitrogen or nitrates. The best results in terms of selectivity to N2 were obtained by using Pt catalysts; a selectivity of 92% to N2 and a TOC removal of 90% were observed in continuous oxidation of the sugarcane vinasse.