Sulfidation extent of nanoscale zerovalent iron controls selectivity and reactivity with mixed chlorinated hydrocarbons in natural groundwater

Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › fagfællebedømt

Dokumenter

Fulltext
Forlagets udgivne version, 4,05 MB, PDF-dokument

Marco C. Mangayayam
Jeffrey Paulo H. Perez
Virginia Alonso-de-Linaje
Knud Dideriksen
Liane G. Benning
Tobler, Dominique Jeanette

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, FeS_m) 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 (k_obs) 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 k_obs trends showed no correlation with CHC reduction potentials based on their lowest unoccupied molecular orbital energies (E_LUMO) but absolute values were affected by the FeS_m shell thickness and crystallinity. In comparison, nZVI reacted with the same CHCs groundwater, yielded k_obs that linearly correlated with CHC E_LUMO values (R² = 0.94) and that were lower than S-nZVI k_obs. The CHC selectivity induced by sulfidation treatment is explained by FeS_m 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.

Originalsprog	Engelsk
Artikelnummer	128534
Tidsskrift	Journal of Hazardous Materials
Vol/bind	431
Antal sider	9
ISSN	0304-3894
DOI	https://doi.org/10.1016/j.jhazmat.2022.128534
Status	Udgivet - 2022

Bibliografisk note

Funding Information:
This research was funded by Metal-Aid Innovative Training Network (ITN), supported by a grant from the European Commission's Marie Sk?owdowska 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

ID: 306108941