摘要
在修复苯系物污染场地时,时常会出现修复效率拖尾、污染物二次释放等问题,这些现象与修复过程中污染物发生相间非平衡态迁移有关。以苯、甲苯和乙苯作为目标污染物,通过沙箱实验研究土壤表面通风、土壤挖掘、土壤气相抽提与热强化气相抽提在应用过程中污染物产生相间非平衡态迁移的程度。研究结果表明:在4种修复中会产生苯系物从土壤向大气扩散的相间非平衡态迁移,造成处理结束后气相苯系物质量分数的反弹。此外,热强化气相抽提能够加快相间传质,从而减轻相间非平衡态迁移,这些结果说明土壤修复过程中普遍存在相间非平衡态迁移,影响土壤修复效果。
Problems such as tailing remediation efficiency and secondary release of pollutants are common during the remediation of sites contaminated by benzene and its derivatives.The phenomena are connected to the interphase nonequilibrium migration of pollutants during the remediation process.This work used sandbox experiment,benzene,toluene and ethylbenzene as model pollutants,to investigate this migration during the application of soil surface ventilation,soil excavation,soil gas extraction and thermally enhanced gas phase extraction.The results showed that nonequilibrium transport that benzene and its derivatives transported from soil to atmosphere occurred in all remediation,leading to the re-elevation of the pollutants concentration in the gas phase.Thermally enhanced gas phase extraction can accelerate the mass transfer inner phase to reduce the negative impact of nonequilibrium transport.Therefore,these results indicated that the nonequilibrium migration is generally present during soil remediation,which have a significant impact on the effectiveness of soil remediation.
作者
孙建强
徐健
张安平
SUN Jianqiang;XU Jian;ZHANG Anping(College of Environment,Zhejiang University of Technology,Hangzhou 310014,China)
出处
《浙江工业大学学报》
北大核心
2023年第4期466-472,共7页
Journal of Zhejiang University of Technology
关键词
土壤修复
沙箱模拟
相间非平衡态迁移
二次污染
soil remediation
sandbox simulation
nonequilibrium transport
secondary pollution
