2种分步浸提方法对土壤中Cr形态提取效果的比较

实验模拟了受铬渣污染的土壤环境,比较在不同活性炭加入量下2种典型分步浸提方法:Tessier 5步法和改进的7步分离方法得到的不同结果,探究适合于铬渣污染对土壤环境的铬形态浸提方法。实验结果表明,2种方法的浸提数据虽有较大差异,但能得到相对一致的变化趋势;七步法形态分类更为细致,99%以上的铬都分布在2~3个结合形态,Tessier五步法的物料衡算结果更为准确(96%~103%),相比七步法形态分类更具包容性,数据更具重现性;随着活性炭的加入,土壤环境中游离铬离子明显减少,转化为有机结合态等更稳定的结合形态,说明活性炭能有效固定土壤环境中游离的铬离子,增加其迁移稳定性。

Comparative assessment of two sequential chemical extraction schemes for fractionation of chromium in polluted soil

With the purpose of establishing the feasibility of the application to distribution studies of chromium contaminants in soils polluted by chromium slag, two widely used chemical extraction methods were compared in this research, involving respectively Tessier 5-step method and improved 7-step method. Results under different treatments carried out show the similar tends despite of significant differences in several forms. 7-step method performs a more detailed classification and 99% of chromium concentrated in 2~3 forms. Tessier 5-step method is more inclusive in formal classification, the extraction data is more efficient and accurate when compare to the material balance(96%~103%). As the addition of activated-carbon, chromium ions in soil reduce significantly, which reveals that porous activated-carbon with large number of oxygen-containing functional groups on the surface can stabilize the chromium ions in soil effectively.