硫化纳米零价铁去除水中三氯乙烯的研究

通过硫化对纳米零价铁 (nZVI) 进行改性, 制备了硫化纳米零价铁 (S-nZVI), 而后对三氯乙烯 (TCE) 进行降解实验研究。利用 SEM、XRD 对 S-nZVI 进行材料的结构表征, 进而研究不同材料、不同 S/Fe 摩尔比、不同初始TCE 浓度、不同初始 pH 条件下, S-nZVI 对 TCE 的降解效果。结果表明, S-nZVI 主要成分为 Fe⁰ 并含有少量的 FeS,制得的 S-nZVI 为球状结构, 表面有片层状的 FeS 生成；当 S/Fe 摩尔比为 0.6, 初始浓度为 20 mg/L 时, TCE 的降解率为 87.2%, 远高于 nZVI (降解率为 56.4%)。经动力学分析后, S-nZVI 去除 TCE 符合伪二级动力学过程, 表明其降解过程以化学还原为主。nZVI 经过硫化后提高了材料的电子选择性, 使其成为修复受污染土壤和地下水的有前途的功能材料。

Research on the Removal of Trichloroethylene from Aqueous Solution by Sulfurized Nano-Zero-Valent Iron

The sulfurized nano-zero-valent iron (S-nZVI) was prepared by modifying nano-zero-valent iron (nZVI) by sulfurization.The degradation experiments of trichloroethylene (TCE) were carried out. The synthesized S-nZVI were characterized by using XRDand SEM. The degradation effect of S-nZVI on TCE was studied under the conditions of different materials, S/Fe molar ration, initialTCE concentrations, and initial pH. The results show that the main component of S-nZVI is Fe⁰ and contains a small amount of FeS.The prepared S-nZVI has a spherical structure with flake FeS formed on the surface. When the S/Fe molar ratio is 0.6 and the initialconcentration is 20 mg/L, the degradation rate of TCE is 87.2%, much better than nZVI (degradation rate 56.4%). After kinetic analysis,the removal of TCE by S-nZVI fitted to the pseudo-second-order kinetic equation, indicating that the degradation process is dominatedby chemical reduction. The sulfurization of nZVI improves the electronic selectivity of the material, making the synthesized S-nZVI apromising material for the remediation of contaminated soil and groundwater.