以某城镇污水处理厂脱水污泥、某面粉厂废弃麦壳、某制药厂废弃黄姜渣为堆肥原料,按1:3:1的体积比进行混合堆肥试验,探讨堆肥过程中污泥物化指标、生物指标及养分的历时变化。结果表明:以城镇污水厂污泥为主要原料,以麦壳和黄姜渣为添加剂,堆肥过程高温阶段维持了12d,含水率按指数关系递减,蠕虫卵死亡率和粪大肠茵群值达到污泥农用的卫生学指标;30d时堆肥的pH值、有机质及氮、磷、钾满足污泥农用的营养学要求,总养分含量和有机质含量分别为56.15和338.54g/kg;堆肥中主要重金属为Cu、Zn、Pb、Cr,但其含量远小于《城镇污水处理厂污泥处置农用泥质》(CJ/T309-2009)的限值。因此,该堆肥产品可以作为农业用有机肥料,并实现了污泥与工业废弃物的同步减量和资源化。
A composting experiment was carried out to explore the variation of physical, chemical, biological and nutrient parameters of the composting. As the main raw materials of the composting, the sewage sludge from a municipal wastewater treatment plant, abandoned wheat chaff from a flour mill and waste turmeric slag from a pharmaceutical factory were mixed together according to a volume ratio of 1 : 3 : 1. The results showed that the high temperature phase could maintain for 12 d and the moisture content was decreased exponentially during the composing process with sewage sludge as the main raw material and wheat chaff and turmeric slag as additives. Meanwhile the mortality rate of worm eggs and the amount of fecal coliform bacteria reached the hygiene indexes for agricultural use of sewage sludge. The pH value, organic matter, nitrogen, phosphorus and potassium could meet the standards for agriculture use, and the contents of total nutrient and organic matter were 56.15 g/kg and 338.54 g/kg respectively when the composing process lasted for 30 d. Moreover the main heavy metals in the composting were copper (Cu) , zinc (Zn) , lead (Pb) and chrome (Cr) , and their contents were far less than the limits in the Disposal of Sludge from Municipal Wastewater Treatment Plant : Control Standards for Agricultural Use ( CJ/T 309 - 2009). Thus the composting product can be used as organic fertilizer in agriculture and the mixed composting can realize the reduction and utilization of dewatered sludge and industrial waste simultaneously.