文献类型：期刊文献

英文题名：Simultaneous stabilization of Pb, Cd, and As in soil by rhamnolipid coated sulfidated nano zero-valent iron: Effects and mechanisms

作者：Song, Huihui[1];Liang, Weiyu[1];Luo, Kailun[1];Wang, Gehui[1];Li, Qiannan[1];Ji, Xiaowen[1];Wan, Jiang[1];Shao, Xuechun[1];Gong, Kailin[1];Zhang, Wei[1,2];Peng, Cheng[1,2]

机构：[1]East China Univ Sci & Technol, Sch Resource & Environm Engn, State Environm Protect Key Lab Environm Risk Asses, Shanghai 200237, Peoples R China;[2]Shanghai Inst Pollut Control & Ecol Secur, Shanghai 200092, Peoples R China

年份：2023

卷号：443

外文期刊名：JOURNAL OF HAZARDOUS MATERIALS

收录：;EI(收录号：20224513067486);WOS:【SCI-EXPANDED(收录号:WOS:000882404100003)】；

基金：Acknowledgements This research was supported by the National Key Research and Development Program of China (2019YFC1805203) and National Nat-ural Science Foundation of China (21737005, 41877124, 42177395) .

语种：英文

外文关键词：Soil remediation; NZVI; Sulfidation; Stabilization of heavy metals; Rhamnolipid

摘要：Sulfidation effectively improves the electron transfer efficiency of nanoscale zero-valent iron (nZVI), but de-creases the specific surface area of nZVI. In this study, sulfidated nZVI (S-nZVI) coated with rhamnolipid (RL-S-nZVI) was synthesized and used to stabilize Pb, Cd, and As in combined polluted soil. The stabilization efficiency of 0.3% (wt) RL-S-nZVI to water soluble Pb, Cd, and As in soil reached 88.76%, 72%, and 63%, respectively. Rhamnolipid coating inhibited the reduction of specific surface area and successfully encapsulated nZVI, thus reducing the oxidation of Fe0. The types of iron oxides in RL-S-nZVI were reduced compared to S-nZVI, but the content and strength of Fe0 iron were obviously enhanced. Furthermore, rhamnolipid functional groups (-COOH and-COO-) were also involved in the stabilization process. In addition, the stabilization efficiency of RL-S-nZVI to the bioavailable Pb, Cd, and As in soil increased by 41%, 41%, and 50%, respectively, compared with nZVI. The presence of organic acids, especially citric acid, improved the stabilization efficiency of RL-S-nZVI to the three metals. The result of BCR sequential extraction indicated that RL-S-nZVI increased the residual state of Pb, Cd, and As and reduced the acid-soluble and reducible state after 28 days of soil incubation. XRD and XPS analyses showed that the stabilization mechanisms of RL-S-nZVI on heavy metals involved in ion exchange, surface complexation, adsorption, co-precipitation, chemisorption, and redox.