砷污染土壤修复中钝化剂的筛选及其工艺条件优化研究

摘要

以广西南丹县砒霜厂周边土壤为研究对象,开展了4种钝化剂修复砷污染土壤的研究.在单因素实验结果基础上,选取钝化时间、土壤粒径和FeSO4/As用量比进行3因素3水平的中心组合设计实验和响应面分析.结果表明,硫酸铁在去除有效态砷方面效果显著.硫酸铁去除有效态砷的最佳工艺条件是:钝化时间22 d,粒径40目,用量FeSO4/As为5.6/1.在此条件下,有效态砷的去除率可达到85.45%.%The soil around the Guangxi Nandan county arsenic factory as the research object,four kinds of passivators were selected to repair As polluted soil.A central composite experiment of three factors and three levels,concluding time,soil particle size and ratio of FeSO4/As,was designed based on the results of single factor experiments.The results were analyzed by response surface methodology with design-expert.The optimal parameters was passivation time of 22 d,optimal particle diameter of soil was 40 mesh.The ratio of FeSO4/As was 5.6/1,under these conditions the removal rate of As effective state can be achieved 85.45%.