Tratamento do efluente gerado na produção de biodiesel utilizando a eletrocoagulação/flotação.

Abstract

Earl ier in the year 2010,5% of biodiesel was added to diesel oil leading to an increase in domestic production of biofuels, however, this increase in production indicated a potential impact on water bodies, since large amounts of wastewater are generated in its production process due to the purification step, which uses water to remove impurities remaining in the biodiesel. The wastewater generated have high contents of oils and grease, chemical oxygen demand (COD) and an alkaline pH and, it is not in accordance with the values established by Resolution 357 of the National Environment Council (CONAMA) for effluent discharges. Hence, the main objective of this work was to use the electrocoagulation /flotation process to treat the wastewater generated during the production of biodiesel, performing a full factorial design 22 with the addition of central points. It was found that the effects of the factors, initial pH and electrolysis time had on the removal rate of turbidity, COD, total solids and oils and greases. With the results was verified that the test number 3 had the best result, achieving a removal rate of turbidity around 99%, removal of total solids in 55%, COD removal of 66% and removal of O&G of 99.34%. Moreover, the results showed that the electrocoagulation / flotation could be an alternative to conventional physical-chemical treatments, as it requires a lower power consumption, short treatment time, and no addition of chemicals coagulants.