A simulation-aided factorial analysis approach for characterizing interactive effects of system factors on composting processes.

A simulation-aided 2-level factorial analysis approach is proposed to characterize the interactive effects of composting factors (i.e. temperature, moisture, oxygen content and initial biomass concentration) on composting processes. To screen the important effect factors when high-order interactions occur, normal probability plot is applied to the result analysis. The results show that the factors have various effects on the composting process in different stages. At the 24th hour, the factors do not show significant effects on the composting process. At the 72nd hour when the composting process reaches active stage, the factors have important effects on the composting process, and their interactive effects are also significant. At the 144th hour, temperature and oxygen content still have effects on the composting process, but not as significant as those at the active stage. These findings could be useful for guiding composting-process operation and management and developing associated control strategies in different composting stages.