摘要
采用还原剂多硫化钙与包封钝化剂水泥等联合修复Cr(Ⅵ)污染土壤,并对修复后土壤中Cr的稳定性进行了阶段跟踪。研究了水溶液中还原剂多硫化钙投加量、pH值变化对Cr(Ⅵ)还原性能的影响,并在土壤中添加还原剂,以及与钝化剂联合修复比较对Cr钝化的效果。研究结果表明,水溶液中,当还原剂多硫化钙添加量为理论计算值的1.03倍时,Cr(Ⅵ)刚好可以被还原去除,且pH在4~10的范围内对Cr的钝化率基本保持稳定;加入修复剂会使弱酸性的土壤pH短暂升高,随后又会逐渐下降至趋于中性;在土壤中,添加理论投加量2倍的还原剂,在此基础上添加15%水泥共同作用,Cr(Ⅵ)均可在短时间内转变为Cr(Ⅲ)。
A combination of the reducing agent calcium polysulphide and encapsulated passivate cement was used to remediate Cr(VI)-contaminated soil,and the stability of Cr in the soil after remediation was followed in stages.This paper investigated the effect of reductant calcium polysulphide dosing in aqueous solution,pH changes on Cr(VI)reduction performance,and the effect of adding reductants to soil,and combined remediation with passivators to compare the effect on Cr passivation.The results of the study show that Cr(VI)can just be removed by reduction in aqueous solution when the reducing agent c alcium polysulphide is added at 1.03 times the theoretical calculated value,and the removal rate of Cr remains basically stable in the pH range of 4-10;the addition of the remediation agent causes a brief increase in the pH of the weakly acidic soil,followed by a gradual decrease to tend to neutral;in the soil,the reduction agent of 2 times the theoretical dosage is added,on the basis of which 15%cement is added for co-action,Cr(VI)can be converted to Cr(Ⅲ)within a short period of time.
作者
李佩珊
冯志刚
黄冲
刘威
张兰英
LI Peishan;FENG Zhigang;HUANG Chong;LIU Wei;ZHANG Lanying(School of Resource Environment and Safety Engineering,University of South China,Hengyang,Hunan 421001,China;Hunan Key Laboratory of Rare Metal Minerals Exploitation and Geological Disposal of Wastes,University of South China,Hengyang,Hunan 421001,China)
出处
《南华大学学报（自然科学版）》
2023年第1期16-23,共8页
Journal of University of South China：Science and Technology
基金
校企合作项目(200KHX081)。
关键词
铬污染
土壤
还原钝化
污染修复
chromium contamination
soil
reduction passivation
contamination remediation
