市政污泥与含氟污泥的环境土工特性比较分析

Analysis of the Environmental and Geotechnique Characters of Sewage Sludge Contrasted with Fluorine- bearing Sludge

通过试验研究了市政污泥和含氟污泥的环境土工特性,并进行了对比分析,得出结论为:两种污泥的含水率、液限、塑限、液性指数、孔隙比、有机质等都很高,除了比重、密度外,市政污泥的各项指标较含氟污泥高;市政污泥溶液为酸性,含氟污泥为碱性;市政污泥中的重金属含量以Cu、Zn居多,而在含氟污泥中污染物为Cr、Sr、Zn、F;市政污泥中Cu的残渣态比例较高,Zn酸溶态比例较高;Cu、Zn的迁移性随溶液碱性增强而降低;含氟污泥中Sr的迁移性随溶液碱性增强而降低;含氟污泥中的氟元素以残渣态为主。Cr主要形态亦为残渣态,Cr的迁移性随着pH值的升高而降低。两种污泥的抗剪强度和渗透性都很低,其中含氟污泥略高,均不能满足填埋要求;两种污泥压缩性都很高,且市政污泥略高;两种污泥的压实性均差,压实效果不佳。

The objective of the research is to investigate the environmental and geotechnique characters of sewage sludge and fluorine- beating sludge.Accordlng to the results, the indexes, water content, liquid limit, plastic limit, liquid character index, void ratio and organic substance, are very high and the other indexes of sewage sludge are higher than those of fluo- rine - bearing sludge excluded to the relative proportion and dettqity; the pH value of sewage sludge is acidity but fluorine - beating sludge is alkalinity; Cu and Zn are the main pollutants in sewage sludge but Cr, St, Zn and F in fluorine- beating sludge; the majority fraction of Cu is residual form but exchangeable fraction in the distribution of Zn in sewage sludge; the mobility of Cu and Zn will decrease with the increase of the solution alkalinity and that of Sr in fluorine - beating sludge also decreases with the increase of the solution alkalinity; In the fluorine- bearing sludge element F mainly shows residual form. Cr also shows residual form and its mobility decreases with the increase of pH. The permeability and shear capacity of two kinds of sludge is also low and that of the fluorine- bearing sludge is a little higher, but both can＇ t meet the requirements for landfill. The compressibility of fluorine- bearing sludge is a little lower than that of sewage sludge, but the compressibil- ity and compaefibility of both are poor.