Electrokinetic-enhanced remediation of actual arsenic-contaminated soils with approaching cathode and Fe0 permeable reactive barrier

Weikang Yao, Zongping Cai, Shuiyu Sun, Martin L. Romantschuk, Aki Sinkkonen, Yan Sun, Qiang Wang

Research output: Contribution to journalArticleScientificpeer-review

Abstract

Purpose The aimof this study was to investigate the remediation efficiency of actual arsenic-contaminated soils by electrokinetic
(EK)-enhanced remediation with approaching cathode and Fe0 permeable reactive barrier (PRB).
Materials and methods Experiments were conducted in a lab-made apparatus consisting of the anode reservoir, the soil specimen
chamber, and the cathode reservoir.
Results and discussion In this study, the enhanced combination methods (approaching cathode and Fe0-PRB) were assisted for
EK remediation of actual arsenic-contaminated soils under a voltage gradient of 1 V/cm and a treatment period of 96 h.
Experimental results showed that arsenic accumulated in the anode sections (I, II) of the soil by employing EK alone with an
arsenic removal rate of less than 5%. In contrast, EK-enhanced remediation with either approaching cathode (EK/AC) or Fe0-
PRB (EK/PRB) reduced the arsenic concentrations in both central and anode sections of the soil and afforded the removal rates of
20% in both cases. However, EK-enhanced remediation with the combination of approaching cathode and Fe0-PRB (EK/PRB/
AC) reached the removal efficiency of 45%without arsenic accumulation in any soil sections. This phenomenon ismainly caused
by the approaching cathode that creates an alkaline environment to promote the migration of arsenic, as well as PRB filled with
Fe0 that achieves the adsorption and immobilization of arsenic.
Conclusions The highest remediation efficiency was achieved in the EK/PRB/AC test, which was attributed to the fact that the
combination of this two methods solved the problem of arsenic accumulation in treated soil and ensured a more thorough arsenic
removal. Furthermore, enhanced remediation efficiency does not elevate the costs.
Original languageEnglish
JournalJournal of Soils and Sediments
Volume20
Pages (from-to)1526–1533
Number of pages8
ISSN1439-0108
DOIs
Publication statusPublished - Mar 2020
MoE publication typeA1 Journal article-refereed

Fields of Science

  • 1172 Environmental sciences
  • Electrokinetic remediation
  • zero valent iron
  • Approaching cathode
  • Arsenic-contaminated soil
  • Electrokinetic remediation
  • Permeable reactive barriers
  • Zero-valent iron
  • HEAVY-METAL POLLUTION
  • RISK-ASSESSMENT
  • CITRIC-ACID
  • REMOVAL
  • GROUNDWATER
  • LEAD
  • IRON
  • TECHNOLOGY
  • ENVIRONMENT
  • SPECIATION

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