市政污泥堆肥过程参数变化及腐熟度综合评价

Parameter Change and Comprehensive Evaluation of Maturity during Municipal Sewage Sludge Composting Process

对市政污泥进行好氧堆肥发酵,测定堆肥过程中的理化指标,并采用灰色关联度法对堆肥腐熟度进行综合评价,提出了污泥堆肥腐熟度的综合评价指标体系。结果表明,污泥堆肥发酵过程中,温度和p H值均呈先升高后降低的变化趋势;温度对堆肥中真菌、细菌数量的变化具有显著影响。采用不同的单一指标对堆肥腐熟度进行评价,并不能得到统一的评价结果;而应用灰色关联度法,对p H值、含水率、种子发芽率、表观指数、C/N降解率、堆温>50℃的天数等指标进行综合评价,可以更加准确地反映污泥堆肥的实际腐熟状况。

The physical and chemical indicators during aerobic composting process of municipal sewage sludge were measured. The comprehensive evaluation of composting maturity was performed using grey correlation degree , and the comprehensive evaluation index system of sludge composting maturity was put forward. The results showed that during sludge composting process, temperature and pH value first increased and then decreased. Temperature had significant effect on variation in number of fungus and bacteria. The unified evaluation results of composting maturity could not be achieved using different sim- ple indicators, while the actual maturity of sludge composting could be accurately reflected using grey correlation degree for comprehensive evaluation of pH, moisture content, seed germination rate, apparent index, C/N degradation rate and number of days with pile temperature higher than 50 ℃.