A Study on Foodwaste Pretreatment for Anaerobic Digestion

혐기성 소화를 위한 음식물쓰레기 전처리 방안에 관한 기초연구

The purpose of this study was to investigate the effective pretreatment of foodwaste for the anaerobic digestion. Considering the foodwaste generation and the anaerobic digester for municipal wastewater sludges, the some pretreatment processes were performed such as the grinding of foodwastes with the addition of water, the mixing with sludges, and the hydrolysis with the addition of NaOH. The results were as followings ; 1. As the stage of feasibility test in laboratory scale, the foodwaste grinding using a household garbage disposer was performed with three different water mixing ratios of 1:1, 1:5 and 1:9 as weight base. The physicochemical characteristics of grinded foodwaste were analyzed and the effective conditions was recommended as the 1 :5mixing ratio of foodwaste and water and the below 8mm particle size. 2. And the mixing of foodwaste and municipal wastewater sludge was studied with three different mixing ratios of 1:9, 3:7 and 5:5 as weight base. The physicochemical characteristics of the mixed foodwaste and sludges were analyzed and the effective mixing ratio was recommended as 3:7 of foodwaste and sludge.

본 연구는 혐기성 소화를 이용한 음식물쓰레기와 하수슬러지 병합처리를 위한 음식물쓰레기 전처리 공정 방안을 모색하기 위하여 수행되었다. 음식물쓰레기 전처리 공정에 따른 음식물쓰레기 단위 공정별 성상 변화와 산발효조 적정 투여 기초조사 및 음식물쓰레기와 하수슬러지 혼합비 특성변화를 통한 산발효조의 효율 향상방안을 검토하였다. 연구결과, 음식물쓰레기의 구성성분은 대부분이 곡류와 채소류로 산발효 공정에서 유기산으로 전환될 가능성이 충분한 것으로 판단되며, 산발효조 투입시 TS의 적정한 범위를 위한 음식물쓰레기와 희석수의 비율은 1:5가 적합한 것으로 나타났다. 음식물쓰레기 분쇄 후 입도 분포 특성을 고려할 때 약 8mm 이하의 입자가 적합하며, 음식물쓰레기와 하수슬러지 슬러지의 혼합비는 3:7 이하가 적합한 것으로 나타났다.