Tratamento Eletroquímico de Efluente de Biodiesel usando Ânodos Dimensionalmente Estáveis

Abstract

Biodiesel is a biodegradable fuel and is an energy alternative to oil and its derivatives. But biodiesel production can cause environmental problems due to the large production of effluent in his cleansing, which is needed to purchase a biodiesel of good quality. The effluent resulting from the production of biodiesel comprise alcohol, glycerin, biodiesel and compounds inherent to the raw materials used, which gives these effluents a very high organic load, which represents a threat to the environment if discharged without treatment appropriate. Existing studies show that this kind of effluent is difficult to treat and conventional systems are not suitable. Thus, this study aimed to evaluate the performance of ADEs Ti/TiRuO2TiO2 and Ti/RuO2IrO2TiO2 in electrochemical treatment of the effluent generated during the production of biodiesel from tallow. To ensure electrical conductivity was used one 0.1 mol L-1 solution of H2SO4 as supporting electrolyte. The electrolyses were carried out in galvanostatic conditions for 12 h, with constant stirring and room temperature. Four current densities (25, 50, 100 and 150 mA cm-2) were evaluated for both electrodes, and the degradation process was followed by measurements of total organic carbon (TOC). The results showed that the TOC removal rate increased as the applied current density was increased, regardless of electrocatalytic material used. The best performance for both electrodes was obtained with the applied current density 150 mA cm-2 for 12 hours electrolysis. The TOC removal was 96.7% when the electrode of Ti/RuO2TiO2 was used and 100% for the anode Ti/RuO2IrO2TiO2. The energy consumption values were proportional to the applied current density during electrolysis, for both electrodes. However, the energy consumption values were very high. The electrode of Ti/RuO2IrO2TiO2 in higher current densities, showed the lower values of energy consumption, indicating greater power efficiency.