冻融循环对含铁材料稳定砷污染土壤的影响  

Effect of freeze-thaw cycles on stabilizing arsenic contaminated soil by ironcontaining materials

作　　者：徐文义[1,2] 李敏[1,2] 黄民生[1,2] 马彤彤 

机构地区：[1]华东师范大学上海市城市化生态过程与生态恢复重点实验室,上海200241 [2]华东师范大学生态与环境科学学院,上海200241 [3]上海立昌环境工程股份有限公司,上海200241

出　　处：《环境工程学报》2017年第12期6497-6503,共7页Chinese Journal of Environmental Engineering

基　　金：国家自然科学基金资助项目(51278192);国家水体污染控制与治理科技重大专项(2014ZX07101012)

摘　　要：为分析冻融循环对污染土壤砷(As)的稳定化性能的影响,投加4种含铁材料(Fe SO_4、Fe S、Fe_2(SO_4)_3和Fe^0)对土壤中的As进行稳定化处理,并通过实验室模拟冻融过程,研究4种含铁材料稳定化处理后土壤中无定形氧化铁含量、氧化铁活化度、p H和As的浸出毒性随冻融循环的变化。结果表明:4种含铁材料稳定化土壤无定形氧化铁含量与氧化铁活化度随冻融循环的变化趋势基本一致;冻融循环降低了无定形氧化铁的含量,促进了铁氧化物的结晶老化。与未冻融土壤相比,冻融循环增加了稳定化土壤As的浸出毒性,但在冻融后期,As浸出毒性的增加量呈降低的趋势。4种含铁材料稳定化土壤As的浸出毒性随冻融循环表现出不同的变化趋势。1%Fe^0稳定化土壤经过冻融循环As的稳定性最高,1%Fe SO_4和1%Fe_2(SO_4)_3稳定化土壤次之,而1%Fe S稳定化土壤最低。因此,冻融循环增加了稳定化土壤As再释放的环境风险,Fe^0用做冻融地区As污染土壤稳定化药剂较为合适。In order to analyze the effects of freeze-thaw cycles on the stabilization performance of arsenic （As）, four kinds of iron-containing materials （FeSO4, FeS, Fe2（SO4）3 and Fe0） were used as stabilizing agents to treat As contaminated soil. The effects of freeze-thaw cycles on the amorphous iron oxide content, activation rate of iron oxide, soil pH and leaching toxicity of As in stabilized soil were studied by laboratory simulation. The results showed that the variation trends of amorphous iron oxide content and activation rate of iron oxide with freeze-thaw cycles were similar in stabilized soil. The freeze-thaw cycles decreased the content of the amorphous iron oxide, promoting crystallization and aging of the iron oxide. The leaching toxicity of As in stabilized soil after freeze-thaw treatment was higher than that in the samples without freeze-thaw treatment. However, the increment of As leaching toxicity showed a reducing trend during the late freeze-thaw cycles. The leaching toxicity of As in soil stabilized by four kinds of iron-containing materials presented different variation trends. The stabilization efficiency of As in 1% Fe0 stabilized soil after continuous freeze-thaw cycles was the best, 1% FeSO4 stabilized soil and 1% Fe2（SO4）3 stabilized soil second, and 1% FeS stabilized soil was most poor. The results of qualitative and quantitative analysis indicated that the freeze-thaw process increased the release risks of As in stabilized soil, and Fe0 was a more suitable stabilizing agent for As contaminated soil in freeze-thaw areas.

关 键 词：冻融循环 砷 含铁材料 稳定化 浸出毒性 

分 类 号：X53[环境科学与工程—环境工程]