TY - JOUR
T1 - Degradation of chlorinated solvents with reactive iron minerals in subsurface sediments from redox transition zones
AU - Yin, Xin
AU - Hua, Han
AU - Dyer, James
AU - Landis, Richard
AU - Fennell, Donna
AU - Axe, Lisa
N1 - Funding Information: We acknowledge this research's support through a contract with Chemours (LBIO-6706/9900403035) and two Project Managers, Edward Lutz and Edward Seger. We appreciate the efforts of DuPont, AECOM, and Summit Drilling in collecting the 18.3-m anoxic core. We also acknowledge Wei Ding, a master student, who contributed to the preliminary study of this research. Publisher Copyright: © 2022 Elsevier B.V.
PY - 2023/3/5
Y1 - 2023/3/5
N2 - Reactive iron (Fe) mineral coatings found in subsurface reduction-oxidation transition zones (RTZs) contribute to the attenuation of contaminants. An 18.3-m anoxic core was collected from the site, where constituents of concern (COCs) in groundwater included chlorinated solvents. Reactive Fe mineral coatings were found to be abundant in the RTZs. This research focused on evaluating reaction kinetics with anoxic sediments bearing ferrous mineral nano-coatings spiked with either tetrachloroethylene (PCE), trichloroethylene (TCE), or 1,4-dichlorobenzene (1,4-DCB). Reaction kinetics with RTZ sediments followed pseudo-first-order reactions for the three contaminants with 90% degradation achieved in less than 39 days. The second-order rate constants for the three COCs ranged from 6.20 × 10-4 to 1.73 × 10-3 Lg-1h-1 with pyrite (FeS2), 4.97 × 10-5 to 1.24 × 10-3 Lg-1h-1with mackinawite (FeS), 1.25 × 10-4 to 1.89 × 10-4 Lg-1h-1 with siderite (FeCO3), and 1.79 × 10-4 to 1.10 × 10-3 Lg-1h-1 with magnetite (Fe3O4). For these three chlorinated solvents, the trend for the rate constants followed: Fe(II) sulfide minerals > magnetite > siderite. The high reactivity of Fe mineral coatings is hypothesized to be due to the large surface areas of the nano-mineral coatings. As a result, these surfaces are expected to play an important role in the attenuation of chlorinated solvents in contaminated subsurface environments.
AB - Reactive iron (Fe) mineral coatings found in subsurface reduction-oxidation transition zones (RTZs) contribute to the attenuation of contaminants. An 18.3-m anoxic core was collected from the site, where constituents of concern (COCs) in groundwater included chlorinated solvents. Reactive Fe mineral coatings were found to be abundant in the RTZs. This research focused on evaluating reaction kinetics with anoxic sediments bearing ferrous mineral nano-coatings spiked with either tetrachloroethylene (PCE), trichloroethylene (TCE), or 1,4-dichlorobenzene (1,4-DCB). Reaction kinetics with RTZ sediments followed pseudo-first-order reactions for the three contaminants with 90% degradation achieved in less than 39 days. The second-order rate constants for the three COCs ranged from 6.20 × 10-4 to 1.73 × 10-3 Lg-1h-1 with pyrite (FeS2), 4.97 × 10-5 to 1.24 × 10-3 Lg-1h-1with mackinawite (FeS), 1.25 × 10-4 to 1.89 × 10-4 Lg-1h-1 with siderite (FeCO3), and 1.79 × 10-4 to 1.10 × 10-3 Lg-1h-1 with magnetite (Fe3O4). For these three chlorinated solvents, the trend for the rate constants followed: Fe(II) sulfide minerals > magnetite > siderite. The high reactivity of Fe mineral coatings is hypothesized to be due to the large surface areas of the nano-mineral coatings. As a result, these surfaces are expected to play an important role in the attenuation of chlorinated solvents in contaminated subsurface environments.
KW - 1,4-dichlorobenzene
KW - Mineral-water interface
KW - Monitored natural attenuation (MNA)
KW - Tetrachloroethene (PCE)
KW - Trichloroethene (TCE)
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U2 - https://doi.org/10.1016/j.jhazmat.2022.130470
DO - https://doi.org/10.1016/j.jhazmat.2022.130470
M3 - Article
C2 - 36493644
SN - 0304-3894
VL - 445
JO - Journal of Hazardous Materials
JF - Journal of Hazardous Materials
M1 - 130470
ER -