Mechanism of emulsifiedzero-valent iron remediation of aquifer contaminated by perchloroethylene
During the remediation of chlorinated hydrocarbon-contaminated aquifers,emulsified zero-valent iron(EZVI)demonstrates high reactivity,strong mobility,and excellent performance without secondary pollution.To elucidate the degradation pathways of perchloroethylene(PCE)in aquifers by EZVI,this study investigates the impact of the degradation process on the mineral composition of aquifer media,as well as the key microbial species and their functions during remediation.The study aims to clarify the mechanism of the EZVI-PCE-aquifer medium-microbial community reaction system in the context of PCE-contaminated aquifer remediation.Three sets of control experiments—EZVI,Emulsified oil(EVO),and inactivated EZVI—were designed to examine the variations in pollutant and mineral ion concentrations across different reaction systems.The aquifer media were characterized using X-Ray Diffraction(XRD)and microbial 16S rRNA gene sequencing.The results indicate that the primary degradation pathways of PCE by EZVI are chemical reduction and bioreduction,with the former accounting for 77.4%of the PCE degradation.The degradation process affects the aquifer medium composition in two ways:the dissolution reactions of potassium feldspar(Kfs)and albite(Ab)under acidic conditions,and the formation of siderite(Sid).The remediation process exerts a selective pressure on the microbial community,resulting in a dominance of Sporacetigenium,Syntrophomonas,and Dechlorosoma,which are associated with anaerobic fermentation to produce acids,methanogenesis,and biotic dechlorination,respectively.
emulsifiedzero-valent ironperchloroethyleneaquifer mediummicrobial community
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维普
