淋洗剂在重金属污染土壤修复中的研究进展

针对镉/铅等一类重金属污染土壤、砷污染土壤，以及镉-铅-砷等复合污染土壤（三类不同重金属污染土壤），就淋洗剂在污染土壤修复中的选用等问题进行综述.总的来看，对于镉/铅等一类重金属污染土壤，螯合剂的去除率较高.如GLDA（谷氨酸N，N-二乙酸）和柠檬酸等，不仅去除率高，而且环境较友好对于砷污染土壤，复合淋洗剂的去除效果比较显著，如NaOH-EDTA对As的去除率较高对于镉-铅-砷等复合污染土壤，复合淋洗剂则更能发挥其所含各类淋洗剂的优势.如NaOH-H₃PO₄与单一淋洗剂相比，对土壤中多种重金属的去除率均较高.笔者认为，同时对土壤中多种重金属均有较高去除率且二次污染较小的复合淋洗剂将是未来的研究重点.

Advances of washing agents in remediation of heavy metal contaminated soil

The research progresses of leaching agents in the remediation of heavy metal contaminated soils were reviewed with focused on three different pollution types, including the soils mainly contaminated by cadmium (Cd) and lead (Pb) of the same category, by arsenic (As), and by the combination of the first two types of heavy metals. In general, the chelating agent for the first type of polluted soil showed higher removal efficiency, especially for GLDA (Glutamic acid, N, N-Diacetic acid), citric acid and so on, which were environment friendly either. For the second type of soil mainly contaminated by As, the removal rate of composite washing agent (CWA) was relatively high like NaOH-EDTA (NaOH-Ethylenediamine tetraacetic acid). In particular, the CWAs, just like NaOH-H₃PO₄, was with very high removal rates compared to the single washing agents for the third type polluted soil. It was suggested that the CWAs with higher removal efficiency for several heavy metals in soil together and less secondary pollution will be the key research points in the future.