【摘要】 在野外现场条件下,开展了硅肥、钙镁磷肥、石灰和骨炭粉等多种材料对镉污染土壤的固定修复研究。结果表明,施用这几种固定剂后不同程度地抑制了玉米(Zeamays L.)对Cd的吸收,其中骨炭粉和石灰的效果最好,在0.5%的施用量下,这两种固定剂可使玉米可食部位Cd含量降低到安全限量标准水平。而其它处理在本研究条件下未能使作物Cd含量降低到安全范围。固定剂抑制植物吸收Cd的效果从大到小顺序依次为:骨炭粉≈石灰﹥硅肥≈钙镁磷肥﹥高炉渣≈钢渣。形态提取分析表明,施用固定剂处理使土壤Cd的水溶态、可交换态和碳酸盐结合态减少,而有机结合态和残渣态增加,说明促进Cd从有效态向缓效/迟效态转化是固定剂抑制植物吸收Cd的重要机制。更多还原

【Abstract】 Under the field condition, effect of six amendments, including silican fertilizer, calcium magnesium phosphate fertilizer, lime and bone char and so forth, on in-situ chemo-immobilization of Cd contaminated soils was investigated. Results show that the applications of amendments restrain the absorption of Cd for plants, wherein the bone char and lime are of highest efficiency. At the amounts of 0.5% level, these two amendments can lower the concentrations of Cd in Zea mays L. to the secure level (not exceeding the guide value of national vegetable sanitation standard (GB 15201-94)). The restraining abilities of these amendments for Zea mays L. to absorb Cd are in the descending order of bone char, lime, silican fertilizer, calcium magnesium phosphate fertilizer, blast fur- nace slag, steel slag. The speciation analysis of Cd in soil shows that the application of these amendments decreases the water-soluble, exchangeable and carbonate-bound forms of Cd but increases the residual and organic-bound forms Cd. This indicates that these amendments have the abilities to promote the transformation of Cd from the active forms to the inactive ones is probably one of the important mechanisms to restrain plants from the absorption of Cd.更多还原