铬污染土壤的单一/复合还原处理及其长期稳定性研究  

Research on effect of single or compound reductive treatment on chromium contaminated soil and its long-term stability

作　　者：姜苹红[1] 陈灿[1] 向仁军[1] 

机构地区：[1]湖南省环境保护科学研究院,长沙410018

出　　处：《环境工程学报》2015年第10期5091-5095,共5页Chinese Journal of Environmental Engineering

基　　金：国家科技支撑计划项目(2012BAJ24B03)

摘　　要：通过短期（2~14 d）和长期监测（1 a）,以及多级萃取步骤（MEP）实验,探讨了焦亚硫酸钠单用或与硫化钙混用对场地铬污染土壤的还原稳定效果及其长期稳定性。结果表明,（1）土壤六价铬含量、总铬和六价铬浸出浓度均随焦亚硫酸钠用量的增加而显著降低,当其用量超过理论值32倍时,六价铬去除率和稳定化效率的增幅明显减小;（2）在自然养护6~14 d之间,土壤六价铬含量出现反弹,但自然养护1 a后,32倍和50倍处理总铬浸出浓度比自然养护2 d时分别降低78.4%和92.5%;（3）在32倍处理基础上,六价铬去除率以及总铬和六价铬的稳定化率均随硫化钙用量的增加而显著提高;（4）自然养护2 d后,T3处理六价铬含量和总铬浸出浓度分别为6 mg/kg和0.1 mg/L,基本满足修复目标要求。此外,T3处理后土壤在酸性水的反复沥滤状态下,仍能保持很低的浸出浓度,具有较好的长期稳定性。The long-term steady effect of the single（ sodium metabisulfite） or mixed（ sodium metabisulfite and calcium sulfide） reduction of chromium contaminated soil was studied through short-term（ 2—14 d） longterm（ 1year） test and multiple extraction procedure experiment. The results are showed as follows：（ 1） the content of Cr（ Ⅵ） in soil and the leaching concentrations of Cr and Cr（ Ⅵ） significantly decrease by increasing the dosage of sodium metabisulfite,but the increasing extent of removed and stabilized rates of Cr（ Ⅵ） significantly reduce when the dosage exceed 32 times than the theoretical value;（ 2） rebounding of Cr（ Ⅵ） content is observed during naturally curing for 6 d to 14 d,but compared to the naturally curing of 2 day,the leaching Cr concentrations of 32 and 50 times treatments respectively decrease 78. 4% and 92. 5% after naturally curing for 1year;（ 3） on the basic of 32 times treatment,the removal rate of Cr（ Ⅵ） and the stabilized rates of Cr and Cr（ Ⅵ） significantly increase by increasing the dosage of calcium sulfide;（ 4） the content of Cr（ Ⅵ） and the leaching Cr concentration of T3 treatment are 6 mg / kg and 0. 1 mg / L,respectively after 2 day of naturally curing,which is basically satisfied to the restoring targets. In addition,the leaching Cr concentration of T3 treatment is very low when undergoing from repetitive precipitation in acid water,which indicates that T3 treatment has good long-term stability.

关 键 词：焦亚硫酸钠 硫化钙 还原 铬 长期稳定性 土壤 

分 类 号：X53[环境科学与工程—环境工程]