School of Environmental Science and Engineering, Donghua University, Shanghai, China.
School of Environmental Science and Engineering, Donghua University, Shanghai, China.
Ecotoxicol Environ Saf. 2020 Dec 1;205:111316. doi: 10.1016/j.ecoenv.2020.111316. Epub 2020 Sep 30.
The interaction between multi-walled carbon nanotubes (MWCNTs) and soil heavy metals was rarely studied. With the convenience of detecting multiple metal elements by ICP-AES, this paper examined the potential effectiveness of MWCNTs on extractability of antimony (Sb) and cadmium (Cd) in contaminated soil. Three-step sequential extraction procedure, toxicity characteristic leaching procedure, bioaccessibility and CaCl single extraction were employed to evaluate Sb and Cd speciations and their extractabilities. According to our results, only at low Sb content level of 100 mg/kg, antimony bioavailability reduced with MWCNTs addition of 0.3% and 0.9% by 22.97% and 20.74%, respectively, which might due to the increase of adsorption point, nevertheless, the excess Sb(OH) was not adsorbed more efficiently. Secondly, due to the difference in effective specific surface area, only under the condition of high content level and MWCNTs addition of 0.1%, the mild acid-soluble fraction increased at most by 15.40% for Sb and 9.40% for Cd, respectively. However, in terms of TCLP-extractable Sb and Cd and CaCl-extractable Sb and Cd, no significant, continuous, regular extractability pattern were found. Overall, MWCNTs were selective on extractability of soil heavy metals due to mechanisms of physical adsorption. This paper provides data reference for the interaction between MWCNTs and soil heavy metals extractability.
多壁碳纳米管 (MWCNTs) 与土壤重金属之间的相互作用很少被研究。本研究利用 ICP-AES 同时检测多种金属元素的优势，考察了 MWCNTs 对污染土壤中锑 (Sb) 和镉 (Cd) 可提取性的潜在有效性。采用三步连续提取程序、毒性特征浸出程序、生物可及性和 CaCl 单提取法来评估 Sb 和 Cd 的形态及其可提取性。结果表明，仅在低 Sb 含量水平（100mg/kg）下，MWCNTs 的添加量为 0.3%和 0.9%时，锑的生物有效性分别降低了 22.97%和 20.74%，这可能是由于吸附点位的增加，但过量的 Sb(OH) 并没有被更有效地吸附。其次，由于有效比表面积的差异，仅在高含量水平和 MWCNTs 添加量为 0.1%的条件下，Sb 的弱酸可溶分数最多增加了 15.40%，Cd 的弱酸可溶分数增加了 9.40%。然而，对于 TCLP 可提取的 Sb 和 Cd 以及 CaCl 可提取的 Sb 和 Cd，并没有发现明显的、连续的、有规律的可提取性模式。总的来说，MWCNTs 对土壤重金属的可提取性具有选择性，这是由于物理吸附的作用机制。本研究为 MWCNTs 与土壤重金属可提取性之间的相互作用提供了数据参考。
