通过气相色谱的方法,利用廉价铁粉对水中四氯化碳进行还原性脱氯,对影响反应速率的因素(Fe°纯度和pH值)、反应产物以及可能的反应路径进行了研究和探讨。结果表明:(1)在实验范围内,pH值对四氯化碳去除效果影响为pH=6>pH=7>pH=8>pH=10;(2)不同pH值条件下,四氯化碳与Fe°发生作用的主要产物之一为氯仿;(3)四氯化碳的去除与氯仿的产生之间存在着一定的对应关系;(4)Fe°纯度和粒径对四氯化碳去除的影响:即3#(Fe°纯度为92%,40~60目)>2#(Fe°纯度为92%,20~40目)>1#(Fe°纯度为84%,20~40目),即Fe°纯度越高,粒径越小,四氯化碳的去除效果越好。研究的结果将为地下水四氯化碳污染的场地修复技术提供理论基础。
The factors that influence the reaction rate(Fe° purity and pH values), reaction products and the possible removal pathway of the reductive dechlorination of CT by using the cheap iron powers were studied and discussed with the method of gas chromatography. The result indicated the effect of pH value on the removal of CT followed the order: pH=6〉pH=7〉pH=8〉pH=10. The main product of the reaction between CT and Fe° was chloroform under different pH values, and there was some corresponding relationship between the removal of CT and the product of chloroform. The effect of the purity and particle size of Fe° on the removal of CT was 3# (Fe°purity:92% ,40~60 mesh)〉2#(Fe°purity:92%, 20~40 mesh)〉1#(Fe°purity:84%, 20~40 mesh), that is, the purer Fe° and the smaller Fe° size, the better the CT removal efficiency. The result of the research can provide theoretical basis for site remediation technologies of CT pollution in groundwater.