Effect Of Electrode Area And Cathode Liquids Composition On Microbial Fuel Cell Performances

Due to complex composition and poor biodegradability, aging landfill leachate wastewater treatment has been difficult. Because its construction cost is relatively cheap and the anode chamber and the cathode chamber substrates have the ability to remove contaminants, the bio-cathode microbial fuel cell(MFC) becomes an effective new technology to treat aging landfill leachate. Bio-cathode microbial fuel cells were built to treat the aging landfill leachate. Effects of electrode surface area and cathode liquids composition of MFC on the electrical propertie and treatment of aging landfill leachate were researched.Electrode area is an important affecting factor for the performance of MFC. The results show that the stable maximum output voltages of the three groups of bio-cathode MFCs are respectively 408 m V, 452 m V and 396 m V when the ratios of anode area and cathode area in those MFCs are respectively 1:2, 2:2, 2:1. The maximum electric power density are 145.73 m W·m-3, 237.65 m W·m-3 and 136.50 m W·m-3, and the resistances, 350Ω, 200Ωand 400Ω, and COD’s removal rates, 21.18%, 20.20%, 22.31%, respectively. After running 30 days, concentration of ammonia, nitrate and nitrite nitrogen in landfill leachate decreased, and ammonia’s removal rates are 80.88%, 73.61% and 66.17%, respectively. Removal efficiencies of ammonia were related with the electricity generation of MFCs.Cathode components are an important affecting factor to the performance of MFC. As the treated aging landfill leachate was used as the cathode liquid, the removal rates of COD, ammonia and nitrate improved respectively 33.74%, 44.32% and 17.92% comparing to traditional MFCs’ technique. The MFC with 75% ratio mixtures of treated aging landfill leachate and aerobic sludge suspension can obtain the largest output voltages(498m V), the largest power density(295.24 m W/m3), the least internal resistance(244Ω), and the largest ammonia removal ratio(601mg). For MFC with 50% ratio mixtures of treated aging landfill leachate and aerobic sludge suspension as cathode liquid, removal rate of the total nitrate nitrogen could be significantly improved.