MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin, 300350, China; Tianjin Engineering Center of Environmental Diagnosis and Contamination Remediation, Tianjin, 300350, China.
MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin, 300350, China.
Chemosphere. 2021 Oct;281:130760. doi: 10.1016/j.chemosphere.2021.130760. Epub 2021 May 11.
Sulfidation treatment is an effective method of improving the catalytic performance of zero-valent iron (ZVI). Here, we prepared sulfidated, micro-sized ZVI (S-mZVI) using ball milling technology to activate persulfate (PS) with the goal of oxidizing organophosphorus pesticides (OPPs) in aqueous solution and aged OPP-contaminated soil columns. Energy dispersive spectroscopy (EDS), X-ray powder diffraction (XRD) and X-ray photoelectron spectrometry (XPS) analyses uncovered the formation of FeO, FeOOH, FeS and FeS in the S-mZVI prepared by ball milling with different proportions of elemental S powder to make micro-sized ZVI particles. The presence of sulfur can regulate the morphology of S-mZVI with a dispersed and spherical shape, and it can improve the activation performance of PS. In aqueous solution, 11.2 mg of S-mZVI activated 2.5 mM PS (S-mZVI-PS) with an S/Fe molar ratio of 0.100, and it was the best at activating PS, leading to oxidation-rate constants of 0.030 s for 10 mg/L phorate and 0.026 s for 10 mg/L terbufos, which were much greater than those of the other S-mZVI and mZVI. The results of the soil column experiment showed that the PS, which had a low consumption for the total dosage, achieved higher degradation percentages among the three OPPs in the S-mZVI-PS treatment than those in the mZVI-PS treatment over 120 h, with the best performance achieved by oxidizing 69.7% phorate, 48.0% terbufos and 60.6% aminoparathion. The effluent concentrations of the three OPPs in the S-mZVI-PS treatment were significantly lower than those in the mZVI-PS treatment, while dissolved total iron and Fe(II) displayed the opposite results. These results indicate that S-mZVI prepared by ball milling can effectively activate PS and be applied to remediate OPP-contaminated soil.
硫化处理是提高零价铁（ZVI）催化性能的有效方法。在这里，我们使用球磨技术制备了硫化的微尺度 ZVI（S-mZVI），以激活过硫酸盐（PS），目标是氧化水溶液中的有机磷农药（OPPs）和老化的 OPP 污染土壤柱。能量色散光谱（EDS）、X 射线粉末衍射（XRD）和 X 射线光电子能谱（XPS）分析揭示了在不同比例的元素 S 粉与微尺度 ZVI 颗粒球磨制备的 S-mZVI 中形成了 FeO、FeOOH、FeS 和 FeS。硫的存在可以调节 S-mZVI 的形态，使其呈分散的球形，并可以提高 PS 的活化性能。在水溶液中，S/Fe 摩尔比为 0.100 的 11.2 mg S-mZVI 激活了 2.5 mM PS（S-mZVI-PS），这是 PS 活化效果最好的条件，导致 10 mg/L 甲拌磷和 10 mg/L 涕灭威的氧化速率常数分别为 0.030 s 和 0.026 s，远大于其他 S-mZVI 和 mZVI。土壤柱实验结果表明，在三种 OPPs 中，PS 在总剂量消耗较低的情况下，在 S-mZVI-PS 处理中比在 mZVI-PS 处理中实现了更高的降解百分比，在 120 h 内，氧化效果最好的是 69.7%的甲拌磷、48.0%的涕灭威和 60.6%的丙溴磷。S-mZVI-PS 处理中三种 OPP 的流出浓度明显低于 mZVI-PS 处理，而溶解总铁和 Fe(II)则呈现相反的结果。这些结果表明，球磨制备的 S-mZVI 可以有效激活 PS，并应用于修复 OPP 污染土壤。
