부산대학교 도서관

The effects of aeration and compost maturity evaluation were investigated in a laboratory scale composting process under four aeration rates. Temperature, moisture, pH, total organic carbon (TOC), volatile fatty acid (VFA), nitrogen compound generation and microorganism succession were monitored during the degradation. When the composting proceeded under the lowest aeration (0.007 L⋅min-1⋅L-1: run 1), a large amount of VFA was produced in the initial composting stage, resulting in a low pH condition in the composter for a long period. Thereafter, temperature, ammonia gas, and NH4+-N increases were delayed. In addition, the lowest numbers of aerobes involved in the reactor were present in run 1. Despite the abundant counts of microorganisms in run 4, the run with the highest airflow rate (0.173 L⋅min-1⋅L-1), the highest final organic residue in this run indicates the lowest metabolic activity due to moisture and heat loss during the composting process. The result suggests that aeration is very important to achieve successful composting and that the suitable airflow rate lies in the range of 0.028 and 0.055 L⋅min-1⋅L-1. Variation of geosmin concentration was also monitored in the composting plant. The geosmin concentration started to decrease once the composting entered the cooling stage. Therefore, geosmin concentration could be a useful parameter for evaluating compost maturity.