Tratamento de vinhaça utilizando processos oxidativos avançado.

Abstract

Vinasse is the main residue obtained in the production of alcohol, for each liter of ethanol produced, 15 liters of vinasse are generated, being characterized as an effluent of high polluting power, about one hundred times greater than that of domestic sewage. Without proper treatment, when released into rivers it compromises the survival of several aquatic beings and when used as fertilizer, untreated effluent can contaminate groundwater and affect terrestrial beings. The objective of this work was to evaluate the efficiency of the advanced oxidative processes for the treatment of vinasse with an emphasis on the removal of organic matter. For this study, a system of treatment of effluents on a bench scale was built, where three Oxidative processes were analyzed: the photolysis of H2O2 / UV, Photo-Fenton and the heterogeneous photocatalysis with TiO2 through a factorial design. The main control parameter in the monitoring of the reactors was the quantification of organic matter, in terms of Chemical Oxygen Demand (COD), and the parameters NTK, Color and total solids. For the photolysis process, there was a removal of 39.40% of organic matter and there was no visible color removal confirmed by the presence of solids in the final effluent. The treatment of vinasse by the photo-Fenton process showed a reduction in COD of 70.81% and 74.06% in color, with the completion of chemical precipitation to complete the reaction cycle of the photo-fenton obtained a reduction in COD of 84.39% and 94.75% of color, verifying that the best conditions for this result were: pH 2, time of 3 hours, molar ratio of H2O2 / Iron 6 and radiation rate of 60W, being more effective in removal of contaminants in relation to photolysis, which obtained a 39% reduction in COD. The results obtained during the treatment using the UV / TiO2 process caused a color reduction of 82.23% and a 64.35% reduction in COD, also showing significant efficiency in the treatment of vinasse.