污泥堆肥对土壤环境和小麦重金属含量的影响

Effects of sewage sludge compost on heavy mental pollution in soil and wheat

污泥中含有大量的有机物、重金属以及病原菌等,不加处理任意排放会对环境造成严重的污染。以中国矿业大学(南湖校区)污水处理厂剩余污泥为研究对象,通过堆肥实验以及堆肥农用的盆栽实验得出,污泥堆肥整体上可以降低污泥中重金属和有机质的含量,TN含量在堆肥过程中先增加但最终下降,TP含量在堆肥过程中有所增加;污泥堆肥农用后,随着堆肥施用量的增加,土壤和小麦中的重金属含量有所增加;土壤中的有机质、TN和TP含量也有所增加;当小麦长势最好时,有机质比空白样增加了27.6%,TP增加了232.4%,TN增加了213.5%;从有机质和TN角度看,污泥堆肥施用量大于20t/hm2时,土壤肥力达到高肥标准。

The sludge sampled from sewage treatment plant in Nanhu campus of China University of Mining and Technology was compost treated and the variation of heavy metals, organic matter, total phosphorus（TP） and total nitrogen（TN） content during the 15 d of composting were investigated. A plot experiment was conducted to investi- gate the effect of sludge composting on heavy mental pollution in soil and wheat. It was found that sludge composting could reduce heavy metals, organic matter and TN content in the sludge, while the content of TP was increased in the composting process. In plot experiment, the heavy mental content in soil and wheat was increased with increasing the compost application rate, the sludge composting improved fertility of soil significantly. In the term of organic and total nitrogen, the fertility of the soil reached the high fertility standard when the content of sludge compost was 20 t/hm^2 , with the content of organic matter, TN, TP were 14.55, 0. 671, 0. 123 g/kg respectively.