Knowledge Agora



Scientific Article details

Title Removal of type-A, type-B, and borderline metals from contaminated soils using zero valent iron and magnetic separation technology: A predictive approach for metal resources recovery
ID_Doc 19313
Authors Alhadidi, QA; Zhou, ZC; Deliz, KYQ; Greenslet, HY; Bonzongo, JCJ
Title Removal of type-A, type-B, and borderline metals from contaminated soils using zero valent iron and magnetic separation technology: A predictive approach for metal resources recovery
Year 2021
Published
DOI 10.1016/j.chemosphere.2021.129980
Abstract Despite the limitations reported on the efficiency of metals used as sorbents, recent advances in chemical and material sciences make it possible to use remediation technologies based on zero valent iron (ZVI) to restore the ecosystem services of metal-contaminated soils. In addition, recent studies showed that remediation by in situ immobilization could be avoided by taking advantage of the strong magnetic characteristics of ZVI. We combined these well-established concepts and conducted laboratory experiments to predict the removal efficiency of metals from contaminated soils based on their chemical classification into type-A, type-B and borderline metals. The Nieboer-Richardson separation of metal ions based on covalent and ionic indexes was used, and beryllium (Be2+), mercury (Hg2+) and lead (Pb2+) were selected as representative of type-A, type-B and borderline, respectively. The results showed a significant decrease in total metal concentrations of treated soils, with a removal efficiency of about 80% for Be, 90% for Pb and 97% for Hg. This ranking followed the increasing order of the covalent indexes, which are 1.11, 3.36, and 3.92 for Be, Pb and Hg, respectively. Therefore, the ability to form strong covalent bonds with oxygen atoms in maghemite (Fe2O3, gamma-Fe2O3) identified on ZVI surfaces seems to drive metal recovery. Validation studies conducted on soil samples collected from sites contaminated with either Pb or Hg, confirmed the above trend. Overall, the results suggest that borderline and type-B metals can be successfully recovered from contaminated soils with rates >= 90%, while the performance would be much lower for type-A metals. (C) 2021 Elsevier Ltd. All rights reserved.
Author Keywords Soil; Metals; Resource recovery; ZVI; Sorption; Magnetic separation
Index Keywords Index Keywords
Document Type Other
Open Access Open Access
Source Science Citation Index Expanded (SCI-EXPANDED)
EID WOS:000642944800119
WoS Category Environmental Sciences
Research Area Environmental Sciences & Ecology
PDF
Similar atricles
Scroll