Journal
WATER RESEARCH
Volume 175, Issue -, Pages -Publisher
PERGAMON-ELSEVIER SCIENCE LTD
DOI: 10.1016/j.watres.2020.115692
Keywords
nZVI; Electrokinetic treatment; Bioremediation; Organohalide-respiring bacteria; Chlorinated ethenes
Funding
- Ministry of Education, Youth and Sports of the Czech Republic [LM2015073]
- Pro-NanoEnviCz - Ministry of Education, Youth and Sports of the Czech Republic [CZ.02.1.01/0.0/0.0/16_013/0001821]
- European Union -European Structural and Investments Funds
- MSMT of the Czech Republic through SGS project of the Technical University of Liberec [21176/115]
Ask authors/readers for more resources
Nanoscale zero-valent iron (nZVI) is recognized as a powerful tool for the remediation of groundwater contaminated by chlorinated ethenes (CEs). This long-term field study explored nZVI-driven degradation of CEs supported by electrokinetic (EK) treatment, which positively affects nZVI longevity and migration, and its impact on indigenous bacteria. In particular, the impact of combined nZVI-EK treatment on organohalide-respiring bacteria, ethenotrophs and methanotrophs (all capable of CE degradation) was assessed using molecular genetic markers detecting Dehalococcoides spp., Desulfitobacterium spp., the reductive dehalogenase genes vcrA and bvcA and ethenotroph and methanotroph functional genes. The remediation treatment resulted in a rapid decrease of the major pollutant cis-1,2-dichloroethene (cDCE) by 75% in the affected area, followed by an increase in CE degradation products methane, ethane and ethene. The newly established geochemical conditions in the treated aquifer not only promoted growth of organohalide-respiring bacteria but also allowed for the concurrent presence of vinyl chloride- and cDCE-oxidizing methanotrophs and (especially) ethenotrophs, which proliferated preferentially in the vicinity of an anode where low levels of oxygen were produced. The nZVI treatment resulted in a temporary negative impact on indigenous bacteria in the application well close to the cathode; but even there, the microbiome was restored within 15 days. The nZVI-EK treatment proved highly effective in reducing CE contamination and creating a suitable environment for subsequent biodegradation by changing groundwater conditions, promoting transport of nutrients and improving CE availability to soil and groundwater bacteria. (C) 2020 Elsevier Ltd. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available