Effect of the external resistance and surface area of graphite electrode on biodegradation of organic matter and generation of bioelectricity in microbial fuel cells

The microbial fuel cells (CCM) is an emerging technology for generation of electrical energy from biodegradable matter, having as catalyst the microorganisms. The objective was to evaluate the generation of bioelectricity and the removal of organic matter in the Microbial Fuel Cells (CCM) from domestic wastewater (ARD). To do this, 5 CCM of double chamber (anaerobic and aerobic) of type "H" were operated at laboratory scale of batch flow, with volume of 1 700 ml, the chambers were connected through a salt bridge (NCL and Agar Agar), electrodes were used of graphite (anode and cathode) connected by a copper cable as an electrical conductor to a fixed external resistance. To evaluate the removal of organic matter, we worked with ARD of different concentrations of COD and for electrical performance, we worked with 3 surface areas of the electrode and external residences. Using Factor ANOVA and Factorial Design 2(2) at 95% confidence level, the interaction of external resistance and surface area of the electrode were significant. The CCM2 stood out against the other CCMs when working with resistance of 50 Omega and surface area of electrode (A(ST)-Grafito) of 151 cm(2), generating an average voltage of 380 mV and 82.3% removal efficiencies (COD). To the by working at lower resistances and greater surface area of the electrode in the CCM, a greater generation of bioelectricity and removal of organic matter from domestic wastewater (ARD) will be obtained, demonstrating the viability and sustainability.