零价铁修复铬污染水体的实验室研究

Remediation of Polluted Water by Chromium Using Zero Valent Iron at Laboratory

以废铁屑为原料,在实验室条件下研究了铬的去除效率和速率,同时研究了铁的投加量、溶液初始酸度、铬起始浓度、小分子阴离子(硫酸根、磷酸根、硝酸根、草酸根、柠檬酸根)等因素的影响,并对反应前后水溶液pH和氧化还原电位的变化作了对比研究。结果表明,铁能很快去除水体中的铬,且铬的去除速率随溶液的pH降低而增快;除柠檬酸根外,其他阴离子的存在均不同程度地促进了铬的去除速率和效率。反应前后,水体pH值升高,氧化还原电位降低。初步探讨了零价铁除铬和小分子阴离子对铬去除影响的机理。

Removal rate and efficiency of chromium from wastewater using zero valent iron was studied at laboratory scale, and influencing factors such as iron mass, initial acidity, chromate concentration as well as at the presence of some anions (sulfate, phosphate, nitrate, oxalic, citric) were discussed. At the same time, changes of pH values and oxidation- reduction potential (ORP) of the solution after treatment were investigated. The result indicated that zero valent iron could removal chromium quickly. The removal rate increased with decreasing pH, and the existence of the anions (except citric) enhanced chromium removal. The solution pH increased and ORP decreased after the treatment. The mechanisms of chromium removal by zero valent iron and the effects of the anions were also depicted.