Optimal turning method of composting regarding hygienic safety

The new turning method was proposed and verified its effectiveness to pathogens by laboratory scale experiments. Considering the results obtained from the previous studies, it could be said that turning of a composting pile was essential in terms of hygienic aspects but the number of turning should be minimized. Effectiveness of inactivation was estimated for each composting run. From this estimation, turning by layers, which is different from conventional turning that mixes compost pile entirely, was proposed and investigated its performance by experiments. Composting operations with static pile method, complete mix(conventional) turning method, and proposed turning(layer turning) method were done and their effectiveness on inactivation of indicator microorganism was evaluated and compared. As results, the conventional turning method was not a proper method in terms of pathogen inactivation, whereas, the proposed turning method showed an excellent performance and should be employed in a composting operation.