Wet air oxidation for industrial wastewater and sludge treatment: first results of a new research program in Quebec

Introduction Sub-critical water technologies, in particular wet air oxidation (WAO), have been developing across Europe in recent decades. This process is now used at the industrial scale for the effective treatment of wet organic material, mainly sludge from wastewater treatment plants (WWTP), and is done with energy self-sufficiency [1, 2]. In WAO, hot pressurised water (200-350 ˚C, 30-200 bars) is enriched with oxygen or air to initiate exothermic oxidation of organic material, mostly into CO2 and H2O. Since the operating temperature is much lower than typical incineration, no gaseous emissions of NOX, dioxins or furans are generated. Water is being kept in a liquid state due to high pressure, avoiding energy losses by vaporisation. These characteristics allow WAO to be a competitive and environmental friendly process for a variety of wet organic wastes and chemical effluents. However, WAO is still non-existent in the province of Quebec (Canada) and unknown to industries. In 2014, Centre de transfert technologique en écologie industrielle (CTTÉI), an applied research center in industrial ecology, acquired a WAO laboratory unit and launched the first research program in this field in the province of Quebec. This program, financed by NSERC (Natural Sciences and Engineering Research Council of Canada), Produits Chimiques Magnus and the City of Sorel-Tracy, aims to study the potential of this technology on various industrial wastes in Quebec and facilitate its transfer to industries. CTTÉI is also supported by European partners Innovation Fluides Supercritiques (IFS) and Aix-Marseille University. Please click Additional Files below to see the full abstract