Maturity indexes and operational parameters during composting municipal solid waste

Using Municipal Solid Waste(MSW) compost as testing materials from Nangong Compost Plant in Beijing which can treat 400t MSW of granularity 15～60 mm everyday, the physical and chemical characteristics, maturity indexes and operational parameters of MSW compost were studied in composting process. During the composting, the content of water reduced, the variety of pH value had an increasing tendency in different seasons, EC value was below the plant limits and will not produce salt toxic action. The E₄/E₆ ratio had an increasing tendency with the maturity of compost. Germination indexes at 24 h and 96 h showed the maturity time of MSW composting may be shortened from eight weeks to five weeks. With the composting time, the contents of total organic carbon(TOC), total nitrogen(TN) and C/N ratio had a decreasing tendency. C/N ratio was negatively correlated with E₄/E₆ ratio and germination indexes at 24 h and 96 h, EC had extremely remarkable negative correlation with E₄/E₆ ratio and germination indexes at 24 h and 96 h, but E₄/E₆ ratio was extremely remarkably positively correlated with germination indexes at 24 h and 96 h.