| Fe3+负载凹凸棒土(Fe/ATP)结构表征及其稳定化修复镉(Cd)机制研究 |
| 摘要点击 3576 全文点击 1799 投稿时间：2015-01-23 修订日期：2015-03-27 |
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| 中文关键词 凹土 Fe/ATP 土壤 镉 浸出浓度 稳定化机制 |
| 英文关键词 attapulgite Fe/ATP soil Cadmium TCLP stabilization mechanism |
| 作者 | 单位 | E-mail | | 杨蓉 | 华中科技大学环境科学与工程学院,环境科学研究所,武汉 430074 | nuanyangyilin@163.com | | 李鸿博 | 华中科技大学环境科学与工程学院,环境科学研究所,武汉 430074 | | | 周永莉 | 华中科技大学环境科学与工程学院,环境科学研究所,武汉 430074 | | | 陈静 | 华中科技大学环境科学与工程学院,环境科学研究所,武汉 430074 | chenjing@hust.edu.cn | | 王琳玲 | 华中科技大学环境科学与工程学院,环境科学研究所,武汉 430074 | | | 陆晓华 | 华中科技大学环境科学与工程学院,环境科学研究所,武汉 430074 | |
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| 中文摘要 |
| 以凹凸棒土(凹土,ATP)为原料,采用浸渍法制备Fe3+负载凹土(Fe/ATP),表征了其结构与形貌, 研究了凹土和Fe/ATP对土壤中镉(Cd)的吸附效果,以浸出浓度作为稳定化评价指标,通过吸附前后凹土和Fe/ATP形貌等特征的变化探讨了稳定化修复Cd机制. 结果表明,加入质量比20%的凹土和Fe/ATP,Cd的浸出浓度分别降低了45%和91%,说明Fe/ATP对土壤中Cd有显著的稳定化作用. 形貌表征分析表明,凹土主要通过结构中的水、—OH基团和晶格缺陷来稳定Cd,而Fe/ATP对土壤中Cd稳定化作用可能主要来自—OH基团以及Fe—O中桥氧的贡献. 凹土与氧化铁均为土壤中天然矿物,廉价易得且环境友好,制备方法简单易实现,该复合材料用于Cd污染土壤的稳定化修复具有较好的应用前景. |
| 英文摘要 |
| Ferric ion modified attapulgite (Fe/ATP) was prepared by impregnation and its structure and morphology were characterized. The toxicity characteristic leaching procedure (TCLP) was used to evaluate the effect of Cadmium(Cd) stabilization in soil with the addition of attapulgite (ATP) and Fe/ATP. The stabilization mechanism of Cd was further elucidated by comparing the morphologies and structure of ATP and Fe/ATP before and after Cd adsorption. Fe/ATP exhibited much better adsorption capacity than ATP, suggesting different adsorption mechanisms occurred between ATP and Fe/ATP. The leaching concentrations of Cd in soil decreased by 45% and 91% respectively, with the addition of wt. 20% ATP and Fe/ATP. The former was attributed to the interaction between Cd2+ and —OH groups by chemical binding to form inner-sphere complexes in ATP and the attachment between Cd2+ and the defect sites in ATP framework. Whereas Cd stabilization with Fe/ATP was resulted from the fact that the active centers (—OH bonds or O- sites) on ATP could react with Fe3+ giving Fe—O—Cd— bridges, which helped stabilize Cd in surface soil. What'more, the ferric oxides and metal hydroxides on the surface of ATP could interact with Cd, probably by the formation of cadmium ferrite. In conclusion, Fe/ATP, which can be easily prepared, holds promise as a potential low-cost and environmental friendly stabilizing agent for remediation of soil contaminated with heavy metals. |
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