미생물연료전지를 이용한 전기 생산 및 폐수 처리 특성

Abstract

Microbial fuel cell (MFC), the process of the energy generation through a wastewater treatment, is the new bio-reactor for generating the electricity. A various species of microorganisms serves as bio-catalysts and energy source. The structure of the reactor are numerous but it is better likely to enlarge the size. the size. Currently, MFC has been considered as an attractive future option for the treatment of wastes and the generation of bio-energy from these wastes. In this research, experiments and theories have been introduced in order to find an optimized operating condition and to increase the electricity productivity of MFC. The characteristics of electricity generation and the wastewater treatment of MFC are analyzed in the treatment process with real wastewater. First, the characteristics of electricity generation and wastewater treatment were examined according to the kinds of the substrate injected into the microbial fuel cell, the operating temperature and pH of a reactor. The increase of substrate concentration directly correlated with the increase in the amount of energy generated. The optimized operating condition of MFC was 35 ℃ and the pH was 7. Second, the density of oxygen and acetate that are carried through an exchange membrane (Nafion 117, Dupont Co, Delaware) was measured for calculating the mass balance of MFC through estimating the mass transfer coefficients and diffusivity. The electric of MFC was researched through calculating the Coulombic balance based on the those data, while MFC was operated. Finally, the electric energy generated in the process of wastewater treatment was measured by applying the real domestic sewage and dairy wastewater to the MFC. After operating MFC, a chemical oxygen demand (COD) of domestic sewage and dairy wastewater decreased over 75% and a biochemical oxygen demand (BOD) was nearly 80%. Total suspended sludge decreased by 45%. And the amount of ammonia nitrogen fall from 40% to 50%. The electric characteristics generated in the process of wastewater treatment, the maximum voltage was 0.54 V (dairy wastewater) and 0.42 V (domestic sewage). The Coulombic efficiency was 62.4% (dairy wastewater) and 52.3% (domestic sewage).