Effect of Different Aeration Methods on Pig Manure Aerated Static Compost Pile

With the recent increased interest in livestock manure compost as an environment friendly organic alternative to fertilizers, the Korea government is strengthening the livestock manure compost quality control system. In this study, the effect of different aeration methods on the quality of pig manure was evaluated by varying the aeration methods for different compost piles and analyzing the changes in their characteristics. For the composting experiment, four compost piles with a volume of 4 m³ were prepared. The four experimental compost piles included one anoxic compost pile (T1), one aerobic compost pile (T2), and two aerobic compost piles with exhaust holes on the surface (T3, T4). The ratio of the surface area of the compost pile and the area of the exhaust hole in T3 was 200.6 (630 cm²: 3,14 cm²) and that of T4 was 100.3 (315 cm² : 3,14 cm²). The amount of air supplied to each compost pile was set at 100 L per minute per 1 m³ of the compost pile. During the composting period, the ambient temperature was maintained at 30±5℃. The temperature of the compost piles rose rapidly after the start of the composting process. The highest temperature of the compost piles was 70℃. The temperature of the compost piles T2, T3, and T4 gradually decreased to the level of the ambient temperature (on the 9th day after starting composting) after reaching the highest temperature. The pH of the compost piles decreased slightly at the beginning of the composting process and then increased again and maintained at approximately 8.55. The VS content of all the compost piles decreased as the composting process progressed. The degree of VS reduction was relatively higher in the T3 and T4 than in T1 and T2 piles. And the degree of VS reduction in T1 and T2 was similar. Based on the seed germination index analysis for each compost pile, T2 and T3 were better than T1 and T4, the highest seed germination index is shown in T2. The time point at which the maturity of all the compost piles reached a completed state was the 9th day from the start of the composting.