Abstract
The purpose of this study is to investigate changes in temperatures and CH4, N2O, and NH3 emissions during the early stage of dairy manure composting using a time-varying intermittent aeration system that automatically controls arbitrary set times of aeration and interval according to the compost temperature range. The experiment performed time-varying intermittent aeration with six different ON/OFF settings in the laboratory-scale composting device and compared it to conventional composting with continuous and intermittent aeration. Our results showed that the modified aeration system increased the duration of high compost temperature above 55 °C compared to conventional composting and simultaneously increased the maximum temperature during composting by up to 5.0 °C. Depending on the setup conditions of the system, even an approximately 80 % reduction in the percentage of aeration time reduced greenhouse gas emissions by up to 58 % compared with conventional continuous aeration composting and simple intermittent aeration. Additionally, this system reduced the NH3 emissions generated during the thermophilic phase of composting by up to 93 %. There is the possibility that the time-varying intermittent aeration method is more effective than the conventional method in suppressing environmentally hazardous gases. The method may also contribute to more hygienic compost production.
