종간직접전자전달 전도체로서 Magnetite(Fe3O4)가 음폐수의 메탄생산에 미치는 영향 = Effects of Magnetite(Fe3O4) as Electrical Conductor of Direct Interspecies Electron Transfer on Methane Yield of Food Wastewater

다국어 초록 (Multilingual Abstract)

Methane production by anaerobic digestion occurs through interspecies electron transfer (DIET), a synthetic metabolism between acetic and methanate bacteria through hydrolysis and acid production steps. In this study, to improve methane yield, the effect of addition of magnetite (Fe3O4), a conductor promoting DIET on methane production in food wastewater was investigated, and the effect on methane yield was assessed by methane potential (Bu) and maximum methane production rate [Rm(t0)] by the operation of batch type anaerobic reactor adding Fe3O4. The Bu and Rm(t0) of food wastewater without Fe3O4 were 0.496 Nm3/kg-VSadded and 38.24 mL/day, respectively. The t0 which reached to Rm appeared at 21.06 days during the operation of the anaerobic reactor. The Bu of food wastewater with Fe3O4 was 0.502, 0.498, 0.512, 0.510, 0.518, 0.523, 0.524, 0.540, and 0.549 Nm3/kg-VSadded in the treatment of 5, 10, 15, 20, 25, 30, 40, 70, and 100mM-Fe3O4, respectively, and the Bu significantly increased to 36.95% with the addition of magnetite in the addition of 15mM-Fe3O4. And, the addition of Fe3O4 shortened the duration to reach Rm from 21.06 days to the maximum of 14.67 days by the addition of Fe3O4. Therefore, the methane yield and production rate of food wastewater significantly improved with the addition of Fe3O4.

국문 초록 (Abstract)

혐기소화에 의한 메탄생산은 유기물이 가수분해, 산생성 단계를 거쳐 아세트산생성균과 메탄생성균 간의영양공생 (syntrophy)에 의해 일어난다. 본 연구에서는 종간 영양공생 기작인 종간직접전자전달 (DIET, Direct Interspecies Electron Transfer) 과정을 촉진시키기 위하여 전도체인 마그네타이트 (Fe3O4 ) 첨가가 음폐수의 메탄생산에미치는 영향을 파악하고자 하였다. 이를 위해, 본 연구에서는 회분식 혐기반응기를 이용하여 마그네타이트 투입량에 따른 음폐수의 메탄퍼텐셜 (Bu )과 최대메탄생산속도 [Rm(t0 )]를 분석하였다. 마그네타이트 무처리구의 메탄퍼텐셜은0.496 Nm3/kg-VSadded이었으며, 21.06일에 38.24 mL/day의 최대메탄생산속도를 보였다. 마그네타이트 5, 10, 15, 20, 25, 30, 40, 70, 100mM 처리구의 메탄퍼텐셜은 각각 0.502, 0.498, 0.512, 0.510, 0.518, 0.523, 0.524, 0.540, 0.549 Nm3/kg-VSadded이었으며, 마그네타이트 투입량 증가에 따라 유의성 있는 메탄퍼텐셜의 증가 경향을 보였다. 최대메탄생산속도는 무처리구와 비교하여 마그네타이트 처리구에서 증가하였으며 15mM 처리구에서 36.95%까지 증가하였다. 또한, 마그네타이트 투입농도가 증가함에 따라 최대메탄생산속도에 도달하는 기간(t0 )은 무처리 21.06일에서마그네타이트 100mM 처리 14.67일로 크게 단축되었다. 따라서, 마그네타이트 투입에 따른 음폐수의 메탄퍼텐셜과최대메탄생산속도가 크게 향상되었다.

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