球磨零价镁/石墨(ZVMg/C)降解水中三氯乙烯

利用机械球磨法制备了零价镁/石墨(ZVMg/C)材料,并将其用于水溶液中三氯乙烯(TCE)的降解。研究通过SEM、BET和XRD等分析手段解析了ZVMg/C的表面形态结构和成分组成;采用正交实验方法优化了ZVMg/C的制备参数,比较了石墨含量对材料性能的影响;并考察了ZVMg/C投加量、溶液初始pH和地下水中常见阴(Cl^-、SO₄^2-、HCO₃^-、NO₃^-)、阳(Fe³⁺、Cu²⁺)离子与ZVMg/C降解TCE的构效关系。研究结果表明,球磨转速和球磨时间是决定ZVMg/C还原能力的两个主要控制参数;ZVMg/C对TCE的降解主要发生在反应的前2 h内,当ZVMg/C投加量为0.2 mol·L^-1时,表面积归一化速率常数(KSA)达到最大为1.31×10^-1 L·h^-1·m^-2;溶液初始pH和常见阴离子对ZVMg/C降解TCE的影响相对较小;而溶液中的Fe³⁺或Cu²⁺能够被ZVMg/C原位还原成金属单质并与ZVMg组成双金属体系促进TCE的还原降解。

Research on the degradation of trichloroethylene in aqueous solution by ball milling Magnesium/Graphite (ZVMg/C)

Zero-valent magnesium/graphite(ZVMg/C)material was prepared by mechanical ball milling and used for the degradation of trichloroethylene(TCE)in aqueous solution.In this study,the surface morphology and composition of ZVMg/C were characterized by means of SEM,BET and XRD analyses.The preparation parameters of ZVMg/C were optimized by the orthogonal experiment method,and the influence of graphite content on the material properties was compared.The structure-activity relationship between ZVMg/C loading,common anions,such as Cl^-、SO₄^2-、HCO₃^-、NO₃^-and cations,such as Fe³⁺、Cu²⁺in groundwater with the degradation of TCE by ZVMg/C were investigated.The results showed that the ball milling speed and ball milling time were the two main controlling parameters to determine the performance of ZVMg/C.The degradation of TCE by ZVMg/C mainly occurred within the first 2 h during the reaction and the surface-area normalized rate constant(KSA)of 1.31×10^-1 L·h^-1·m^-2 was maximum with ZVMg/C loading of 0.2 mol·L^-1.The initial pH of the solution and common anions had relatively moderate effects on the degradation of TCE by ZVMg/C,while Fe³⁺or Cu²⁺in the solution could be reduced to Fe⁰ or Cu⁰ by ZVMg/C in situ and formed a bimetallic system with ZVMg to enhance TCE dechlorination.