粉煤灰污泥添加剂对地下水质影响的模拟研究

通过测定土柱和淋洗液中重金属的含量,研究石灰岩质土壤应用粉煤灰污泥添加剂改良后重金属在土壤剖面上的分布移动特征及对地下水质的影响.结果表明:仅试验层内除As和Ni外,Zn、Cd、Pb、Cu、Cr、Hg含量明显增加,未出现明显向下移动的趋势；同时重金属淋出量明显增加,但未超过地下水Ⅲ级标准.初步认为与添加剂自身、重金属的特性及石灰岩质土壤滤层的截固作用相关.粉煤灰污泥经过合理的配施和预处理应用于石灰岩质矿区退化土壤的改良,短期内不会对地下水的质量产生明显的影响.

A Simulation Research on Effects of Fly Ash-and Sewage Sludge Ameliorant to Groundwater Quality

Land disposal of fly ash(FA) and sewage sludge(SS) are major problems due to their potentially harmful constituents.In this paper,leaching experiment was performed to discuss the potential environmental hazard of FA and SS to the groundwater when they were used as amendments of calcareous soil in a limestone mining area.The results showed that the contents of extractable Zn、Cd、Pb、Cu、Cr、Hg in L11 and L12 columns were higher than those of in the control except As、Ni.But they mainly accumulated in the top amended soil and the ameliorant had no significant effect on the downward migration of metals.Furthermore,leaching of metals from soil columns amended with low to high rates of FA-SS mixture generally had a slightly impact on the metal content of the leachate,and metals contents met the second class environmental quality standards of groundwater.At the same time,the results indicated that combining usage of FA and SS at a rational rate of application should not cause significant effect on drainage water quality.