Electiricity production from domestic wastewater with microbial fuel cell

Increase in the use of fossil fuels to meet energy needs has accelerated environmental problems and the need of renewable energy has increased steadily. Clean and renewable energy is one of the most important needs of human life. Mankind has been in a constant quest to meet this need This quest has found new energy sources as time goes by. One of these new energy sources is Microbial Fuel Cell (MFC). In this thesis two different MFC reactors were investigated to produce power using domestic wastewater. Also surface properties of the membranes used in MFCs were examined. Dual-Chamber MFC with different membrane and electrode configurations were tested and electricity generation from different hydraulic retention time (HRT) were investigated. Maximum current density 1385 mA/m2 and power density 16 mW/m2 were obtained with, Ti-TiO2-Nafion, the lowest current density 480 mA/m2 and power density 2 mW/m2 were obtained with Carbon paper-Ultrex electrode-membrane configuration for 1 day of HRT. Obtained current and power density from Ti-TiO2-Ultrex and Carbon paper-Nafion for 1 day of HRT were 750 mA/m2, 5 mW/m2 and 1320 mA/m2, 14 mW/m2, respectively. The highest COD removal efficiency was obtained 78% with Ti-TiO2-Nafion couple and 74% with Carbon paper-Nafion. In the study of UM2FC fed by domestic wastewater concentrate, maximum power density was 35 mW/m2 with 50% concentrate stream. Also COD removal efficiency was 67% and ohmic resistance was determined to be 85 ohms in UM2FC according to electrochemical measurements. Total resistance and charge transfer resistance were measured as 135 ohms and 50 ohms, respectively. In the end of study, the deterioration of the membrane surface was evaluated with SEM and EDX analysis and organic and inorganic deposits were determined on the membrane surface.