Análise comparativa de desempenho entre filtros anaeróbios convencionais e modificados para integração em células de combustível microbianas

Abstract

We highlight the growing need to produce electrical energy from renewable sources, on a global demand scale. This work aimed to bring a holistic view of energy production and effluent treatment, as the management of waste produced and the demand for energy is a present problem in our society. To this end, a bench-scale anaerobic filter structurally modified to compose the anode of a microbial fuel cell made of galvanized metal with a ring-shaped cathode, made of graphite and operated without a membrane, and a conventional anaerobic filter with filling made of galvanized metal. The filters were operated with a hydraulic retention time (TDH) of 50 hours, with a useful volume of 500 mL and fed with a synthetic effluent based on powdered milk with an average chemical oxygen demand (COD) of 1,500 mg.L-1 . Aspects such as: total and volatile solids, temperature, methane concentration, pH, alkalinity and chemical oxygen demand were analyzed. Statistical tests showed that the microbial fuel cell has similar performance to the anaerobic filter, achieving greater COD reductions of 35%, while the conventional filter showed a reduction of 24%. In the other parameters there were no significant statistical differences between the reactors' performances. The modified anaerobic filter achieved an average voltage of 1.17 V and an average power density of 286 mW.m-2 . Thus, within the conditions used, it was possible to observe that the microbial fuel cell proved to be more efficient than the conventional filter in reducing COD.