Effects of common groundwater ions on the transformation and reactivity of sulfidized nanoscale zerovalent iron.

Autor: Mangayayam MC; Nano-Science Center, Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100, Copenhagen, Denmark. Electronic address: mc.marco@chem.ku.dk., Alonso-de-Linaje V; AECOM Environment, Madrid, Spain; GIR-QUESCAT, Departamento de Quimica Inorgánica, Universidad de Salamanca, Salamanca, Spain., Dideriksen K; Geological Survey of Denmark & Greenland (GEUS), Øster Voldgade 10, 1350, Copenhagen, Denmark., Tobler DJ; Nano-Science Center, Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100, Copenhagen, Denmark. Electronic address: dominique.tobler@nano.ku.dk.
Jazyk: angličtina
Zdroj: Chemosphere [Chemosphere] 2020 Jun; Vol. 249, pp. 126137. Date of Electronic Publication: 2020 Feb 06.
DOI: 10.1016/j.chemosphere.2020.126137
Abstrakt: Sulfidized nanoscale zerovalent iron (S-nZVI) is an Fe-based reactant widely studied for its potential use for groundwater remediation. S-nZVI reactivity has been widely investigated testing various contaminants in various water matrices, but studies on S-nZVI corrosion behaviour and reactivity upon exposure to complex groundwater chemistries are limited. Here, we show that anoxic aging of S-nZVI for 7 days in the absence and presence of key groundwater solutes (i.e., Cl - , SO 4 2- , Mg 2+ , Ca 2+ , HCO 3 - , CO 3 2- , NO 3 - , or HPO 4 2- ) impacts Fe 0 corrosion extent, corrosion product and reduction rates with trichloroethene (TCE). White rust was the dominant corrosion product in ultrapure water and in SO 4 2- , Cl - , Mg 2+ or Ca 2+ solutions; green rust and/or chukanovite formed in HCO 3 - and CO 3 2- solutions; magnetite, formed in NO 3 - solutions and vivianite in HPO 4 2- solutions. The aged S-nZVI materials expectedly showed lower reactivities with TCE compared to unaged S-nZVI, with reaction rates mainly controlled by ion concentration, Fe 0 corrosion extent, type(s) of corrosion product, and solution pH. Comparison of these results to observations in two types of groundwaters, one from a carbonate-rich aquifer and one from a marine intruded aquifer, showed that S-nZVI corrosion products are likely controlled by the dominant GW solutes, while reactivity with TCE is generally lower than expected, due to the multitude of ion effects. Overall, these results highlight that S-nZVI corrosion behaviour in GW can be manifold, with varied impact on its reactivity. Thus, testing of S-nZVI stability and reactivity under expected field conditions is key to understand its longevity in remediation applications.
(Copyright © 2020 The Authors. Published by Elsevier Ltd.. All rights reserved.)
Databáze: MEDLINE
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