Facile Combinations of Thiosulfate and Zerovalent Iron Synergically Immobilize Cadmium in Soils through Mild Extraction and Facilitated Immobilization.
Facile Combinations of Thiosulfate and Zerovalent Iron Synergically Immobilize Cadmium in Soils through Mild Extraction and Facilitated Immobilization.
复制标题
硫代硫酸盐和零价铁的简单组合通过温和萃取和促进固定化协同固定土壤中的镉。
DOI：
10.1016/j.jhazmat.2020.124806
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发表时间：
--
影响因子：
13.6
通讯作者：
Cai Xiyun
中科院分区：
文献类型：
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作者：
Wang Maolin;Hu Canyang;Xu Jiahui;Jing Xudong;Rahim Hafeez Ur;Cai Xiyun
镉(Cd)是环境中释放的毒性最大的物质之一。Cd污染土壤通常具有大量的生物可利用态Cd物种，并导致种植的粮食作物中Cd的过量积累。稳定固定土壤中Cd的处理方法是可取的。在此，我们报道了硫代硫酸盐(STS)和零价铁(ZVI)的简单组合增强了土壤中Cd的固定，并减少了Cd在小麦中的积累。STS通过形成可溶的Cd(S2O3)x络合物温和激活土壤中的Cd，而中间产物(如硫酸盐和硫化物)和ZVI协同促进土壤中Cd的固定。这种协同作用归因于促进了与Cd结合亲和力高的FeOOH的形成，以及稳定的硫酸盐-Cd-FeOOH络合物的形成和低可利用性的CdSx的形成。STS-ZVI处理使土壤中残留Cd增加101-123%，使小麦地上部Cd积累量减少13-68%，这取决于化学成分和二元试剂的剂量。田间施STS和ZVI(0.06~0.11 kg/m2)使籽粒Cd减少24~39%。
Cadmium (Cd) is one of the most toxic substances released in the environment. Cd-contaminated soils usually have a large pool of bioavailable Cd species and lead to excessive Cd accumulation in planted cereal crops. Treatment methods for stable immobilization of Cd in soils are desirable. Here we reported that facile combinations of thiosulfate (STS) and zerovalent iron (ZVI) reinforced Cd immobilization in soils and reduced Cd accumulation in wheat. STS mildly activated Cd in soils through the formation of soluble Cd(S2O3)xcomplexes, whereas intermediates of STS (e.g., sulfate and sulfides) and ZVI synergically facilitated immobilization of Cd in soils. The synergy was ascribed to the facilitated formation of FeOOH with high Cd-binding affinity and formation of stable sulfate-Cd-FeOOH complexes and poorly available CdSx. STS-ZVI treatments increased residual Cd in soils by 101–123% and decreased Cd accumulation in wheat shoots by 13–68%, depending on chemical compositions and doses of binary reagents. Field applications of STS and ZVI (0.06–0.11 kg/m2) demonstrated 24–39% reductions of grain Cd.