Abstract
A food waste composting apparatus of 450 L was designed for and tested with changing conditions of inlet air flow rate, agitation and inoculation. Agitation was done twice per day for 5 min and inlet air flow rate was set as 22.7 L/min for RUN 1. For RUN 2 and RUN 3, agitation was continuous, and inlet air flow rate was changed frequently as 10 L/min, 15 L/min and 20 L/min in order to maintain temp. above 5$0^{\circ}C$, and the concentration of $O_2$over 7 mol%. The compost of RUN3 was inoculated with 10 wt% of accomplished compost, and it was compared with RUN 1 and 2 to show the effect of inoculation. The composting rates of RUN 2 and RUN 3 were faster than that of RUN 1, because agitation was continuous and temperature was controlled in RUN 2 and RUN 3. Inoculated RUN 3 was better than RUN 1 and RUN 2 in the concentrations of $CO_2$and reduction of volatile solids. while the effect of inoculation on C/N ratios, pH change and the numbers of microoragnisms was not clearly appeared.
용량 450 L의 음식물 쓰레기 퇴비화 장치를 설계하여, 유입공기량, 교반, 접종 조건에 변화를 주어 퇴비화 장치의 성능을 실험하였다. RUN 1은 1일 2회 5분간 교반하고, 유입공기량을 22.7 L/min로 고정하였다. RUN 2, 3에서는 지속적으로 교반하고, 유입공기량은 퇴비내부의 온도를 5$0^{\circ}C$ 이상 유지하고, 또 산소농도를 7 mol% 이하로 떨어지지 않도록 10 L/min, 15 L/min, 20 L/min으로 수시로 조절하였다. RUN 3는 접종효과를 보기 위하여 퇴비에 완성된 퇴비를 10 wt% 접종하여 RUN 1, 2와 비교하였다. 지속적으로 교반하고, 온도와 산소 농도에 따라 유입공기량을 조절한 RUN 2와 3에서 RUN 1보다 더 빠른 퇴비화가 이루어졌다 .그리고, $CO_2$농도와 휘발성 유기물 감소에서는 접종한 RUN 3가 RUN 1, 2보다 높았으나, C/N 비, pH 변화, 미생물 개체수에서는 뚜렷한 접종효과가 나타나지 않았다.
