Final product of sewage sludge composting by recycling matured compost

摘要

Pilot-scale experiment was conducted on composting of sewage sludge from urban wastewater by recycling matured compost as a bulking agent. At the given ratio of sludge to matured compost = 1∶2(v/v), and aeration rate 0.05m³/(m³·min), final product was gained and analyzed by measurement of nutrient (nitrogen, phosphorus, and Potassium), heavy metals, and polyacrylamide (PAM). As the experiment shown, PAM, as a kind of hazardous material in sludge, was degraded by 80.6% during composting, and only 1.17mg/g remained in the final product. Different kinds of heavy metals were concentrated after composting, and the total content of heavy metals increased by 42%∼49%. Plenty of nutrients (N, P, and K) remained in the final product after composting, which was in favor of the application of final compost to plants growth.