Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; Jiangsu Engineering Laboratory for Soil and Groundwater Remediation of Contaminated Sites, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China.
School of Environmental Science and Engineering, Tianjin University, Tianjin 300350, China.
J Hazard Mater. 2021 Sep 5;417:125993. doi: 10.1016/j.jhazmat.2021.125993. Epub 2021 May 6.
The removal mechanism from the reductive dechlorination of trichloroethylene (TCE) by zero valent magnesium (ZVMg) in aqueous solution is systematically studied. Following the preparation and characterization of ball-milled micro ZVMg with graphite (ZVMg/C) particles, this paper evaluated the TCE reaction rates, pathways, utilization rates and aging effects of ZVMg/C particles in aqueous solution under uncontrolled pH conditions. Overall, 38 μM of TCE was transformed by 10 g/L of ZVMg/C to methane (62.51%) and n-hexane (11.86%) and ethane (7.40%) and other alkene and alkyne products through the catalytic hydrogenation pathway. The measured surface area normalized pseudo-first order rate constants (K) were up to 9.31 × 10 L/m/h and the utilization rate of Mg accounted for around 60%. The K were decreased to 1.90 × 10 L/m/h in case of ZVMg/C being exposed in the atmosphere for 6 days due to 7.3% reduction in the utilization rate of Mg from the initial 85.2%, and 5.11 × 10 L/m h in case of ZVMg/C aged in water for one day. The removal efficiencies of approximately 56%, 58% and 87% by 10 g/L of ZVMg/C were achieved in the contaminated groundwater comprising 38 μM of TCE, 43 μM of 1,2-dichlorobenzene and 8.12 μM of trichlormethane. Therefore, it is concluded that ZVMg/C is viewed as a potential and effective remediation reagent for the groundwater remediation.
系统研究了零价镁（ZVMg）在水溶液中还原脱氯三氯乙烯（TCE）的去除机制。在制备和表征球磨微 ZVMg 与石墨（ZVMg/C）颗粒后，本文评估了在无控制 pH 条件下，ZVMg/C 颗粒在水溶液中的 TCE 反应速率、途径、利用率和老化效应。总体而言，10g/L 的 ZVMg/C 将 38μM 的 TCE 转化为甲烷（62.51%）、正己烷（11.86%）和乙烷（7.40%）以及其他烯烃和炔烃产物，通过催化加氢途径。测量的比表面积归一化拟一级速率常数（K）高达 9.31×10 L/m/h，Mg 的利用率约为 60%。如果 ZVMg/C 在大气中暴露 6 天，由于 Mg 的利用率从初始的 85.2%降低了 7.3%，则 K 降低至 1.90×10 L/m/h，如果 ZVMg/C 在水中老化 1 天，则 K 降低至 5.11×10 L/m/h。在含有 38μM TCE、43μM 1,2-二氯苯和 8.12μM 三氯甲烷的污染地下水（ZVMg/C）中，分别实现了约 56%、58%和 87%的去除效率。因此，可以得出结论，ZVMg/C 被视为地下水修复的一种有潜力和有效的修复试剂。
