TY - JOUR
T1 - Roles of reactive iron mineral coatings in natural attenuation in redox transition zones preserved from a site with historical contamination
AU - Hua, Han
AU - Yin, Xin
AU - Fennell, Donna
AU - Dyer, James A.
AU - Landis, Richard
AU - Morgan, Scott A.
AU - Axe, Lisa
N1 - Funding Information:
We gratefully acknowledge support for this research through a contract (LBIO-6706/9900403035) with the Chemours Company (United States) and Project Managers Ed Lutz and Ed Seger. We thank the entire team that collected the anaerobic core at the site as well as technical support provided by Chemours, DuPont, and AECOM.
Funding Information:
We gratefully acknowledge support for this research through a contract ( LBIO-6706/9900403035 ) with the Chemours Company (United States) and Project Managers Ed Lutz and Ed Seger . We thank the entire team that collected the anaerobic core at the site as well as technical support provided by Chemours, DuPont, and AECOM.
Publisher Copyright:
© 2021 Elsevier B.V.
PY - 2021/10/15
Y1 - 2021/10/15
N2 - In this study, a protocol was developed to identify reduction-oxidation (redox) transition zones in an effort to exploit natural source zone depletion processes. A sediment core with a total length of 18-m was collected from a site with historical contamination that includes chlorinated benzenes where the redox condition was preserved. In the four redox transition zones investigated, reactive iron coatings are characterized with a suite of analyses under anaerobic conditions. To distinguish surface coating mineralogy, X-ray diffraction, X-ray fluorescence, and field-emission scanning electron microscopy with an energy dispersive X-ray analyzer were applied along with a six-step sequential extraction process. The cycling of Fe and S, as an important contribution and indicator of ongoing natural attenuation processes for constituents of concern (COC), was delineated by using data from multiple and complementary analyses for isolating and identifying iron phases. Along with groundwater chemistry, contaminant concentrations, and microbial genera, attenuation of COCs is expected to be active and sustainable in redox transition zones, where there is an abundance of reactive iron mineral coatings cycling through biogeochemical reactions. Reactions in other redox transition zones may be limited where iron mineral coatings are not dominant.
AB - In this study, a protocol was developed to identify reduction-oxidation (redox) transition zones in an effort to exploit natural source zone depletion processes. A sediment core with a total length of 18-m was collected from a site with historical contamination that includes chlorinated benzenes where the redox condition was preserved. In the four redox transition zones investigated, reactive iron coatings are characterized with a suite of analyses under anaerobic conditions. To distinguish surface coating mineralogy, X-ray diffraction, X-ray fluorescence, and field-emission scanning electron microscopy with an energy dispersive X-ray analyzer were applied along with a six-step sequential extraction process. The cycling of Fe and S, as an important contribution and indicator of ongoing natural attenuation processes for constituents of concern (COC), was delineated by using data from multiple and complementary analyses for isolating and identifying iron phases. Along with groundwater chemistry, contaminant concentrations, and microbial genera, attenuation of COCs is expected to be active and sustainable in redox transition zones, where there is an abundance of reactive iron mineral coatings cycling through biogeochemical reactions. Reactions in other redox transition zones may be limited where iron mineral coatings are not dominant.
KW - Biogeochemical degradation
KW - Chlorinated benzene
KW - Natural attenuation
KW - Reactive iron mineral coatings
KW - Redox transition zones
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U2 - 10.1016/j.jhazmat.2021.126600
DO - 10.1016/j.jhazmat.2021.126600
M3 - Article
C2 - 34271444
AN - SCOPUS:85109824090
SN - 0304-3894
VL - 420
JO - Journal of Hazardous Materials
JF - Journal of Hazardous Materials
M1 - 126600
ER -