不同物料堆肥腐熟度评价指标的变化特性

为探讨工厂化好氧堆肥的堆肥周期及腐熟度评价体系,提高工厂堆肥效率,选取上海地区不同来源典型的9种物料,采用工厂化工艺进行堆肥试验,对堆体的温度、含水率、pH、C/N、w(OM)、ρ(NH₄+-N)、ρ(NO₃--N)、ρ(DOC)、ρ(DOC)/ρ(DON)及GI(种子发芽指数)腐熟度评价指标变化规律进行研究. 结果表明:堆肥腐熟度受多方面因素影响,T〔(C/N)终点/(C/N)起点)〕与w(OM)、ρ(NH₄+-N)、GI、ρ(DOC)/ρ(DON)之间相关性显著,T、ρ(NH₄+-N)、GI 3个指标能准确有效地判断堆肥腐熟情况,堆肥结束后T在0.50~0.59之间,ρ(NH₄+-N)为301~346 mg/L,GI为81.31%~91.03%. 不同物料堆肥腐熟难易程度不同,通过聚类分析将9种物料分为5类:第1类,厨余、杂草、生活垃圾、园林垃圾；第2类,果蔬、污泥；第3类,秸秆；第4类,鸡粪；第5类,猪粪. 厨余、杂草、生活垃圾、园林垃圾、污泥、秸秆堆肥成分复杂较难腐熟,需要35 d达到腐熟标准；鸡粪及猪粪堆肥结构简单较易腐熟,29 d即可达到腐熟标准. 据此可适当将工厂化堆肥周期缩短为35 d. 

Study of Maturity Parameter Characteristics in Composting Process Using Different Materials

In order to explore the composting cycle and the compost maturity evaluation system, the effectiveness of maturity parameters during the composting process was assessed based on chemical and biological measurements. The parameters included temperature, moisture content, pH, C/N, Organic Matter (OM), NH₄+-N, NO₃--N, dissolved organic carbon (DOC), the ratio of DOC to dissolved organic nitrogen (DON) and Germination Index (GI). The samples included nine typical compost sources in Shanghai. The results showed that T value (the ratio of C/N at initial stage and C/N at final stage of composting), OM, NH₄+-N, NO₃--N, DOC/DON and GI were correlated with each other. The parameters indicated that the compost maturity was affected by the combination of all parameters, but not necessarily by each measure individually. The results suggested that T value, NH₄+-N and GI were more suitable for use as indicators of the compost maturity than others. In order to describe the level of maturity, a hierarchical cluster analysis was performed based on T value, NH₄+-N and GI. At the end of composting, the ranges of T value, NH₄+-N and GI were from 0.50 to 0.59,1 to 346 mg/L and 81.31% to 91.03%, respectively. The different composts were clustered into five groups:the first group included kitchen waste (KW), lawn waste (LW), municipal solid waste (MSW) and green waste (GW); the second group were sludge (S) and fruit and vegetable waste (FVW); the third group was primarily straw waste (SW); the fourth group was composed of chicken manure (CM); and the fifth group was pig manure (PM). According to the parameters of compost maturity (T value, NH₄+-N and GI), the maturity was lower in KW, LW, MSW and GW, which reached an acceptable level of stability in 35 days, while the maturity was higher in CM and PM, which reached an acceptable level of stability in 29 days. The results suggested that the composting process with different materials could come to an end in 35 days based on the compost technology.