The sugar and ethanol industry has been expanding in the Brazilian economy since the 70s, milestone of the successive global crisis on the supply of fossil fuels. Among the alternative renewable sources, ethanol is obtained from the fermentation of the sugars contained in the raw material of vegetable origin (e.g. sugar cane and corn).However its production is characterized by the generation of a significant volume of vinasse, the main wastewater resulting from the distillation step, being generated on average 13L for every liter of ethanol produced. Vinasse contains a high concentration of organic matter, besides significant levels of macro and micronutrients and acidic and corrosive characteristics. Thus, the high polluting potential of vinasse indicates the need to reduce its polluting load prior to its land disposal. Among the available technologies, anaerobic digestion (AD) should be highlighted by presenting several benefits, such as the reduction of the polluting load and the generation of energetic compounds, such as hydrogen and methane. Despite the feasibility of this technology, studies show that some compounds, found in significant concentrations in vinasse, may interfere negatively with anaerobic digestion, such as sulfate (SO42-), whose concentrations in vinasse tend to increase during the crop cycle of sugarcane. Thus, based on the lack of studies addressing the influence of sulfate on the AD of vinasse, the present project aims at analyzing the influence of the ratio DQO/SO42- on the anaerobic digestion of vinasse from sugarcane, considering both the degradation of organic matter and the production of methane. In this context, the kinetic parameters that describe the behavior of anaerobic digestion applied to vinasse will be obtained for different ratios DQO/SO42-.
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