摘要
DCB在土壤和地下水中频繁检出,对环境和人体健康构成潜在风险,亟需开发绿色、高效和降解彻底的修复技术.本研究首先利用合成的纳米Pd/Fe进行了地下水中DCB的动力学还原脱氯以及不同环境因子影响实验,在此基础上进一步提出一种耦合纳米Pd/Fe还原和微生物降解联合修复土壤和地下水中DCB污染的新思路.结果表明,Pd/Fe对3种DCB的还原速率呈现以下趋势:p-DCB>m-DCB>o-DCB.p-DCB的还原速率与Fe投加量和Pd负载量呈正相关,10 g·L^(-1)0.2%纳米Pd/Fe在15 min内能完全去除10 mg·L^(-1) p-DCB,p-DCB还原符合准一级反应动力学,还原速率K_(obs)为0.2366 min^(-1).阴离子影响实验表明纳米Pd/Fe还原p-DCB受NO_(3)^(-)离子抑制最为显著,抑制率为35.3%.然而,单独的纳米Pd/Fe还原实验只能将DCB还原至B,而耦合纳米Pd/Fe还原和微生物降解联合技术可以彻底降解DCB,土壤和地下水中的B、CB和DCB在20 h的时间内总去除分别为85.1%和100%.纳米Pd/Fe还原和微生物好氧降解联合去除DCB,能解决化学还原不彻底和直接生物降解效率低问题,在DCB污染场地修复中具有应用潜力.
Dichlorobenzene(DCB)is frequently detected in soil and groundwater,posing serious hazard to the environment and human health,thus requiring the development of green,efficient,and thoroughly degrading remediation technologies.In this study,the synthesized nano-Pd/Fe was used in the investigation of DCB reduction and dechlorination experiments in groundwater,both kinetics and key environmental factors studies were carried out.Based on these results,a new technology coupled with nano-Pd/Fe reduction and microbial degradation for the completely destruction of DCB inform soil and groundwater was proposed.The results demonstrated that the reduction rates of the three DCB isomers by Pd/Fe followed the trend p-DCB>m-DCB>o-DCB.The reduction rate of p-DCB was positively correlated with Fe dosing and Pd loading,and 10 g·L^(-1)0.2%nano-Pd/Fe could-completely remove 10 mg·L^(-1) p-DCB within 15 min,following quasi-primary reaction kinetics.Anion-influenced experiments revealed that NO_(3)^(-) had the most significant inhibitory effect on p-DCB reduction,with an inhibition rate of 35.3%.Howerer,DCB reduction was end with benzene in pure nano-Pd/Fe reduction system,while the coupled nano-Pd/Fe reduction and microbial degradation technique resulted in complete degradation of DCB,with total removal of B,CB and DCB from soil and groundwater over a 20 h period of 85.1%and 100%,respectively.Coupled treatment with nano-Pd/Fe reduction and aerobic microbial degradation can solve the incompleteness of chemical reduction and the limited efficiency of biological oxidation,which has the potential for application in remediation of DCB-contaminated sites.
作者
袁波
贡玉凤
欧阳霁
杨洁
罗启仕
崔长征
YUAN Bo;GONG Yufeng;OU Yangji;YANG Jie;LUO Qishi;CUI Changzheng(State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process,School of Resources and Environmental Engineering,East China University of Science and Technology,Shanghai 200237;State Environmental Protection Engineering Center for Urban Soil Contamination Control and Remediation,Shanghai Academy of Environmental Sciences,Shanghai 200233;Department of Environmental Science and Engineering,Fudan University,Shanghai 200438;Shanghai Shenglong Environmental Co.,Ltd,Shanghai 200235)
出处
《环境科学学报》
CAS
CSCD
北大核心
2023年第11期33-41,共9页
Acta Scientiae Circumstantiae
基金
国家重点研发计划重点专项(No.2018YFC1803300)
国家自然科学基金资助项目(No.42207469)。
关键词
二氯苯
还原脱氯
零价铁
联合修复
地下水修复
dichlorobenzene
reductive dechlorination
zero-valent iron
combined restoration
groundwater remediation
