脱水污泥的土地利用对比研究

为了解脱水技术对后续污泥土地利用的影响，以3种典型脱水污泥为研究对象，分别与土壤等质量混合作为栽培基质用于黑麦草盆栽试验，通过植物种植后复合基质的有机质含量、pH、容重、孔隙率等理化性质的分析以及黑麦草生长状况的观测，研究经过不同脱水工艺的污泥对土壤改良效果的影响。采用土柱溶淋实验模拟1年降水，研究电解脱水污泥对环境的风险。结果表明经过电解脱水、机械压滤脱水后的污泥对土壤持水、保水能力有较好的效果；选用电解脱水污泥作为土壤改良剂，模拟1年自然降水后，对渗滤液中Cu、Cr、Cd、Pb、Ni等重金属含量进行测定，初步判定电解脱水污泥的污染风险较小。

COMPARATIVE STUDY ON LAND USE OF DEHYDRATED SLUDGE

Three typical dewatered sludge were taken as research objects, and mixed with soil as the cultivation substrate for potted experiment of ryegrass, in order to understand the effect of dehydration on subsequent land use of sludge. By measuring the organic matter content, pH, bulk density, porosity and other physical and chemical properties of the composite matrix after planting, and observing the growth status of ryegrass, the influence of sludge through different dehydration processes on soil improvement was studied. Soil column leaching experiment was used to simulate 1 year’s precipitation, the environmental risk of electrolytic dewatering sludge was studied. The key research results were as follows: the dehydrated sludge by electrolysis and mechanical pressure filtration had good effect on soil water retention; the content of Cu, Cr, Cd, Pb, Ni in leachate was determined by using electrolytic dehydrated sludge as the soil conditioner after simulating 1 year’ natural precipitation, which proved electrolytic dewatered sludge pollution risk was low.