Search

Implementation of greener (close to zero pollution) product manufacturing is gaining relevance, but the end-stream treatment will still be imperative in the future for the sustainable development of the petrochemical, chemical and pharmaceutical industry. Phenol, o-cresol, m-xylene. o-chlorophenol, p-nitrophenol, aniline, nitrobenzene, sulfolane and two industrial process wastewater from phenolic resin production were studied. Applying 140°C and 9 bar of O 2 catalytic wet air oxidation over active carbon can destroy phenol, o-cresol, m-xylene, and o-chlorophenol. Refractory compounds including aniline, p-nitrophenol, and particularly sulfolane and nitrobenzene, required either hydrogen peroxide promotion or pure wet peroxide oxidation at ≤ 550°C for nitrobenzene. In view of such extreme conditions, the use of Fenton reagent, when applicable, seems an alternative to soften the treatment severity. Although almost complete phenol destruction and medium to high COD reduction was achieved, none of the treatment tested could be recommended as the best solution. Wastewater treatment has to be case specific due to the complex and varying composition of real effluents. Combined chemical-biological processes appear to be technically and economically feasible, the chemical oxidation being a pre-treatment to destroy non-biodegradable substance (and partially COD). This is an abstract of a paper presented at the 7th World Congress of Chemical Engineering (Glasgow, Scotland 7/10-14/2005).