Effect of stacking height on maturity during composting of municipal solid waste under 0-15 mm sieved

Based on 0-15 mm screened municipal solid waste from Beijing Majialou Municipal Solid Waste Transfer Station, the research using closed static technology was conducted in the tunnels of Nan Gong Composting Factory to understand the feasibility of small size municipal solid waste composting and select the optimum heap high of composting. Four treatments were arranged, which had different heap heights namely 2.5, 2.0, 1.5 and 1.0 m, respectively. Samples taken from each treatment after eight day of high temperature composting were analyzed with the maturity indexes including electric conductivity (EC), E4/E6, water soluable carbon (WSC), NH4+-N, C/N, germination index (GI), value of fecal coliform, which was combined with a fuzzy comprehensive evaluation to evaluate the maturity. The results showed that 0-15 mm municipal solid waste could be composted individually, and the optimum maturity heap heights were 1.5 m and 1.0 m. But the optimum heap height of tunnel composting was 1.5 m when there was more integration.