저가형 탄화수소막을 이용한 미생물 연료전지의 전기생산 특성

Abstract

Microbial fuel cell (MFC) is a new type of energy converter that converts the chemical energy in organic materials to electrical energy through microbial catalysis. The MFC can be used as a source of sustainable energy because it can produce electrical energy from organic contaminants by the treatment of wastewater or waste. The essential components of an MFC are anode chamber, cathode chamber, and proton exchange membrane (PEM). The PEM sends H+ ions generated in the anode chamber to the cathode chamber, while simultaneously increasing the energy conversion efficiency by restricting oxygen delivery. The Nafion membrane is widely used as a PEM in fuel cells owing to its excellent oxidation resistance, and alkali resistance at high temperatures. However, the Nafion membrane is high-priced and has a low selectivity for H+ ions. Thus, the development of a new cost-effective PEM that can replace the expensive Nafion membrane is required. In this study, a low-cost hydrocarbon membrane, was prepared by the sulfonation process using poly(2,6-dimethyl-1,4-phenylene oxide) for use as a PEM instead of the expensive Nafion membrane. The properties of this hydrocarbon membrane such as the amount of electricity generated and the wastewater treatment characteristics were examined by applying it to the MFC process. When the low-cost hydrocarbon membrane produced in this study was compared with the commercial Nafion 117 membrane, the hydrocarbon membrane showed better dimensional stability to changes in temperature and lower water contents compared to the commercial Nafion 117 membrane. Therefore, the hydrocarbon membrane is expected to exhibit excellent mechanical properties in the fully hydrated condition. The electricity generated and the wastewater treatment characteristics of the low-cost hydrocarbon membrane were analyzed by applying it to a continuous MFC process as the PEM. After an adaptation period of six days in the early stage of the operation of microorganisms, a maximum voltage of 498 mV was obtained on day 7, which was maintained stably for a long period. Furthermore, the chemical oxygen demand removal efficiency increased to 75.8% after seven days of operation, and the removal efficiency remained stable for a long period. The long-term stable operation of the MFC is attributed to the accretion of microorganisms to the anode and the effective formation of microbial films. Therefore, the low-cost hydrocarbon membrane prepared in this study exhibits great potential to replace the expensive Nafion membrane as the PEM of the MFC for long-term operation.