Fan Liren, Song Jiqing, Bai Wenbo, Wang Shengping, Zeng Ming, Li Xiaoming, Zhou Yang, Li Haifeng, Lu Haiwei
Faculty of Materials Science and Chemistry, China University of Geosciences (Wuhan), Wuhan, Hubei 430074.
Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing 100081.
Sci Rep. 2016 Feb 16;6:21027. doi: 10.1038/srep21027.
A soil remediation method based on magnetic beneficiation is reported. A new magnetic solid chelator powder, FS@IDA (core-shell Fe3O4@SiO2 nanoparticles coated with iminodiacetic acid chelators), was used as a reactive magnetic carrier to selectively capture non-magnetic heavy metals in soil by chelation and removal by magnetic separation. FS@IDA was prepared via inorganic-organic and organic synthesis reactions that generated chelating groups on the surface of magnetic, multi-core, core-shell Fe3O4@SiO2 (FS) nanoparticles. These reactions used a silane coupling agent and sodium chloroacetate. The results show that FS@IDA could chelate the heavy metal component of Cd, Zn, Pb, Cu and Ni carbonates, lead sulfate and lead chloride in water-insoluble salt systems. The resulting FS@IDA-Cd and FS@IDA-Pb chelates could be magnetically separated, resulting in removal rates of approximately 84.9% and 72.2% for Cd and Pb, respectively. FS@IDA could not remove the residual heavy metals and those bound to organic matter in the soil. FS@IDA did not significantly alter the chemical composition of the soil, and it allowed for fast chelating capture, simple magnetic separation and facilitated heavy metal elution. FS@IDA could also be easily prepared and reprocessed.
报道了一种基于磁选的土壤修复方法。一种新型磁性固体螯合剂粉末FS@IDA（包覆亚氨基二乙酸螯合剂的核壳结构Fe3O4@SiO2纳米颗粒）被用作反应性磁性载体，通过螯合作用选择性捕获土壤中的非磁性重金属，并通过磁选去除。FS@IDA通过无机-有机和有机合成反应制备，这些反应在磁性、多核、核壳结构的Fe3O4@SiO2（FS）纳米颗粒表面生成螯合基团。这些反应使用了硅烷偶联剂和氯乙酸钠。结果表明，FS@IDA能够螯合水不溶性盐体系中Cd、Zn、Pb、Cu和Ni的碳酸盐、硫酸铅和氯化铅等重金属成分。生成的FS@IDA-Cd和FS@IDA-Pb螯合物能够通过磁选分离，Cd和Pb的去除率分别约为84.9%和72.2%。FS@IDA不能去除土壤中的残留重金属和与有机物结合的重金属。FS@IDA不会显著改变土壤的化学成分，并且它能够实现快速螯合捕获、简单磁选以及促进重金属洗脱。FS@IDA也易于制备和再加工。
