中文摘要：

为探讨不同改性明矾浆能否作为修复中、低度Cd和Pb污染土壤的重金属钝化剂,采用土培实验研究了不同改性明矾浆和系列添加浓度对污染土壤中可提取态Cd和Pb含量的影响。结果表明：土壤中可提取态Cd和Pb的含量随明矾浆添加量的增大和钝化时间的延长而降低,其中同等钝化剂添加量条件下,热碱改性明矾浆钝化土壤中Cd和Pb的能力优于其他三种明矾浆,如添加浓度为5.0%,放置时间为16周的热碱改性明矾浆处理,其可提取态Cd和Pb含量分别为1.04、19.87 mg·kg^-1,与对照相比（可提取态Cd和Pb含量分别为2.12、50.8 mg·kg^-1）,降幅分别为51%和60.9%,均达到显著水平（P〈0.05）。扫描电镜和比表面积测试结果证实,原明矾浆经过热碱改性后其粒径变小,比表面积增大,增加了明矾浆与污染物的接触面积,使其与重金属的吸附固定能力有所提高,可以有效降低土壤中重金属Cd和Pb的可提取态含量,从而降低其生物有效性。

英文摘要：

Alum powder has fine size, large surface area and strong adsorption, and could be used to reduce heavy metal concentrations in soil solution. Here alum powder, hot acid alum powder, hot alkali alum powder and thiol modified alum powder were applied to cadmium（Cd）and lead（Pb）contaminated soils to assess their efficiency in immobilization of soil Cd and Pb. Application of all alum powder decreased extractability of Cd and Pb in soils. Extractable Cd and Pb were negatively correlated with the amounts of alum powder and incubation time. Hot alkali alum powder was the most effective in decreasing extractable Cd and Pb in soil. Scanning electron microscopy showed that hot alkali alum powder had smaller particle sizes and greater specific surface area than the original one did. The results of this study would be of practical importance in screening amendments for remediation of Cd and Pb contaminated soil.