铬污染土壤的固化稳定化及药剂还原的修复研究  

Remediation of Chromic-contaminated Soil by Solidification/stabilization and Chemical Reduction Technology

作　　者：刘国[1] 余雯雯[1] 陈春梅[1] 何娟 赖学明 LIU Guo;YU Wenwen ;CHEN Chunmei;HE Juan;LAI Xueming(Dept. of Environmental Science and Engineering, College of Environment and Civil Engineering,Chengdu University of Technology Chengdu 610059)

机构地区：[1]成都理工大学环境与土木工程学院环境科学与工程系,成都610059

出　　处：《工业安全与环保》2018年第3期68-72,共5页Industrial Safety and Environmental Protection

摘　　要：采用室内模拟试验的方法,研究使用水泥为固化剂,石灰、粉煤灰为稳定剂,FeSO_4·7H_2O,Na_2S·9H_2O,Na_2SO_4为还原剂时,不同养护时间(5,7,14,21,28 d)、固化剂/稳定剂/还原剂不同添加量对铬污染土壤中六价铬浸出浓度的影响,来模拟对某铬污染产地的修复情况;并进行正交试验,得出最佳修复工艺。结果表明,随养护时间增加,添加固化剂、稳定剂可以固化/稳定化土壤,降低铬污染土壤的Cr(Ⅵ)浸出浓度,养护28 d期间,添加固化剂、稳定剂的土壤的Cr(Ⅵ)浸出浓度分别降低了99.4%~99.9%,64.3%~99.2%,3%~76.2%。在养护28 d时,随固化剂、稳定剂、还原剂的添加量增加,固化、稳定、还原效果相应增强,土壤Cr(Ⅵ)浸出浓度达到场地表层土壤的修复目标值45.37 mg/kg。正交实验表明最佳修复工艺为每修复200 g污染土壤,添加200 g水泥,100 g石灰,1.75倍的理论反应量硫酸亚铁。相关分析表明,固化剂水泥、稳定剂石灰的使用能够固化稳定铬污染土壤的Cr(Ⅵ),还原剂硫酸亚铁能将Cr(Ⅵ)还原为毒性较低的Cr(Ⅲ),从而达到修复铬污染土壤的目的。The curing agent Cement and stabilizer limestone and fly ash can be respectively added into chromic-contaminated soil to conduct the experiment of remediation,in which the effects of curing time(5,7,14,21,28d)on leaching concentration of Cr(VI)were investigated,on the basis of optimum curing time,the simulated remediation of contaminated soil was researched by analysing the effects of curing agent,stabilizer,reducing agent FeSO4·7H2O,Na2S·9H2O and Na2SO3in different addition amount on lixiviate consistency of Cr(VI)and also the orthogonal experiment was carried out to obtain the optimal remediation technology.The results indicated that,with the increase of curing time,the leaching concentration of Cr(VI)decreased and approximately99.4%~99.9%,64.3%~99.2%,3%~76.2%of Cr(Ⅵ)was removed by cement,limestone and fly ash respectively during28days.On the28th day,the leaching concentration of Cr(VI)reduced to the target value45.37mg/kg of surface soil remediation with the increase of amount of cement,limestone,fly ash,FeSO4·7H2O,Na2S·9H2O and Na2SO3.The orthogonal experiments suggested that200g cement,100g lime and1.75times theoretical dose of ferrous sulphate(FeSO4)should be required for the optimal remediation of per200g contaminated soil.According to relevant analysis,the solidification and stabilization of chromic-contaminated soil can be achieved by using cement and lime,in which Cr(VI)can be reduced to Cr(III)with lower toxicity by ferrous sulphate(FeSO4),so that the remediation can be accomplished.

关 键 词：铬污染 固化 稳定 还原 修复 

分 类 号：X53[环境科学与工程—环境工程]