TY - JOUR
T1 - Sulfidation extent of nanoscale zerovalent iron controls selectivity and reactivity with mixed chlorinated hydrocarbons in natural groundwater
AU - Mangayayam, Marco C.
AU - Perez, Jeffrey Paulo H.
AU - Alonso-de-Linaje, Virginia
AU - Dideriksen, Knud
AU - Benning, Liane G.
AU - Tobler, Dominique J.
N1 - Funding Information:
This research was funded by Metal-Aid Innovative Training Network (ITN), supported by a grant from the European Commission's Marie Skɫowdowska Curie Actions Program under project number 675219. The authors thank Theis Brock-Nannestad for support with GC-MS measurements. LGB and JPHP acknowledge the financial support of the Helmholtz Recruiting Initiative grant No. I-044-16-01. Part of the data was acquired at Advanced Photon Source, a U.S. Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under contract no. DE-AC02-06CH11357. Support for travel to the synchrotron facility came from the Danish Council for Independent Research (via DANSCATT).
Funding Information:
This research was funded by Metal-Aid Innovative Training Network ( ITN ), supported by a grant from the European Commission’s Marie Skɫowdowska Curie Actions Program under project number 675219 . The authors thank Theis Brock-Nannestad for support with GC-MS measurements. LGB and JPHP acknowledge the financial support of the Helmholtz Recruiting Initiative grant No. I-044-16-01 . Part of the data was acquired at Advanced Photon Source, a U.S. Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under contract no. DE-AC02-06CH11357 . Support for travel to the synchrotron facility came from the Danish Council for Independent Research (via DANSCATT).
Publisher Copyright:
© 2022 The Authors
PY - 2022/6/5
Y1 - 2022/6/5
N2 - Sulfidated nanoscale zerovalent iron (S-nZVI) exhibits low anoxic oxidation and high reactivity towards many chlorinated hydrocarbons (CHCs). However, nothing is known about S-nZVI reactivity once exposed to complex CHC mixtures, a common feature of CHC plumes in the environment. Here, three S-nZVI materials with varying iron sulfide (mackinawite, FeSm) shell thickness and crystallinity were exposed to groundwater containing a complex mixture of chlorinated ethenes, ethanes, and methanes. CHC removal trends yielded pseudo-first order rate constants (kobs) that decreased in the order: trichloroethene > trans-dicloroethene > 1,1-dichlorethene > trichloromethane > tetrachloroethene > cis-dichloroethene > 1,1,2-trichloroethane, for all S-nZVI materials. These kobs trends showed no correlation with CHC reduction potentials based on their lowest unoccupied molecular orbital energies (ELUMO) but absolute values were affected by the FeSm shell thickness and crystallinity. In comparison, nZVI reacted with the same CHCs groundwater, yielded kobs that linearly correlated with CHC ELUMO values (R2 = 0.94) and that were lower than S-nZVI kobs. The CHC selectivity induced by sulfidation treatment is explained by FeSm surface sites having specific binding affinities towards some CHCs, while others require access to the metallic iron core. These new insights help advance S-nZVI synthesis strategies to fit specific CHC treatment scenarios.
AB - Sulfidated nanoscale zerovalent iron (S-nZVI) exhibits low anoxic oxidation and high reactivity towards many chlorinated hydrocarbons (CHCs). However, nothing is known about S-nZVI reactivity once exposed to complex CHC mixtures, a common feature of CHC plumes in the environment. Here, three S-nZVI materials with varying iron sulfide (mackinawite, FeSm) shell thickness and crystallinity were exposed to groundwater containing a complex mixture of chlorinated ethenes, ethanes, and methanes. CHC removal trends yielded pseudo-first order rate constants (kobs) that decreased in the order: trichloroethene > trans-dicloroethene > 1,1-dichlorethene > trichloromethane > tetrachloroethene > cis-dichloroethene > 1,1,2-trichloroethane, for all S-nZVI materials. These kobs trends showed no correlation with CHC reduction potentials based on their lowest unoccupied molecular orbital energies (ELUMO) but absolute values were affected by the FeSm shell thickness and crystallinity. In comparison, nZVI reacted with the same CHCs groundwater, yielded kobs that linearly correlated with CHC ELUMO values (R2 = 0.94) and that were lower than S-nZVI kobs. The CHC selectivity induced by sulfidation treatment is explained by FeSm surface sites having specific binding affinities towards some CHCs, while others require access to the metallic iron core. These new insights help advance S-nZVI synthesis strategies to fit specific CHC treatment scenarios.
KW - Chlorinated ethenes, ethanes and methanes
KW - Corrosion
KW - Iron sulfide
KW - Metallic iron
KW - Remediation
UR - http://www.scopus.com/inward/record.url?scp=85125657799&partnerID=8YFLogxK
U2 - 10.1016/j.jhazmat.2022.128534
DO - 10.1016/j.jhazmat.2022.128534
M3 - Article
C2 - 35259697
AN - SCOPUS:85125657799
SN - 0304-3894
VL - 431
JO - Journal of Hazardous Materials
JF - Journal of Hazardous Materials
M1 - 128534
ER -