In situ speciation studies of copper-humic substances in a contaminated soil during electrokinetic remediation

Research output: Contribution to journalArticle

25 Citations (Scopus)

Abstract

Speciation of copper-humic substances (HS) in the electrokinetic remediation (EKR) of a contaminated soil was studied by in situ extended X-ray absorption fine structure (EXAFS) and X-ray absorption near edge structure (XANES) spectroscopies. The least-square fits of the XANES spectra suggested that the main Cu species in the contaminated soil were Cu-HS (50%), CuCO 3 (28%), Cu2O (11%), and CuO (11%). The Cu-HS in the contaminated soil possessed equatorial and axial Cu-O bond distances of 1.94 and 2.17 Å with coordination numbers (CNs) of 3.6 and 1.4, respectively. In the EKR process, the axial Cu-O bond distance in the Cu-HS complexes was increased by 0.15 Å, which might be due to a ligand exchange of the Cu-HS with H2O molecules in the electrolyte. After 180 min of EKR, about 50% of the Cu-HS complexes (or 24% of total Cu) in the soil were dissolved and formed [Cu(H2O)6]2+ in the electrolyte, 71% (or 17% of total Cu in the soil) of which were migrated to the cathode under the electric field (5 V/cm). This work exemplifies the use of in situ EXAFS and XANES spectroscopies for speciation studies of Cu chelated with HS in the contaminated soil during EKR.

Original languageEnglish
Pages (from-to)1280-1287
Number of pages8
JournalJournal of Environmental Quality
Volume33
Issue number4
DOIs
Publication statusPublished - 2004

All Science Journal Classification (ASJC) codes

  • Environmental Engineering
  • Water Science and Technology
  • Waste Management and Disposal
  • Pollution
  • Management, Monitoring, Policy and Law

Fingerprint Dive into the research topics of 'In situ speciation studies of copper-humic substances in a contaminated soil during electrokinetic remediation'. Together they form a unique fingerprint.

  • Cite this