Remediating explosive-contaminated groundwater by in situ redox manipulation (ISRM) of aquifer sediments

H. K. Boparai, S. D. Comfort, P. J. Shea, J. E. Szecsody

Research output: Contribution to journalArticle

32 Scopus citations

Abstract

In situ chemical reduction of clays and iron oxides in subsurface environments is an emerging technology for treatment of contaminated groundwater. Our objective was to determine the efficacy of dithionite-reduced sediments from the perched Pantex Aquifer (Amarillo, TX) to abiotically degrade the explosives RDX (hexahydro-1,3,5-trinitro-1,3,5-triazine), HMX (octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine), and TNT (2,4,6-trinitrotoluene). The effects of dithionite/buffer concentrations, sediments-solution ratios, and the contribution of Fe(II) were evaluated in batch experiments. Results showed that reduced Pantex sediments were highly effective in degrading all three high explosives. Degradation rates increased with increasing dithionite/buffer concentrations and soil to solution ratios (1:80-1:10 w/v). When Fe(II) was partially removed from the reduced sediments by washing (citrate-bicarbonate buffer), RDX degradation slowed, but degradation efficiency could be restored by adding Fe(II) back to the treated sediments and maintaining an alkaline pH. These data support in situ redox manipulation as a remedial option for treating explosive-contaminated groundwater at the Pantex site.

Original languageEnglish (US)
Pages (from-to)933-941
Number of pages9
JournalChemosphere
Volume71
Issue number5
DOIs
StatePublished - Mar 1 2008

    Fingerprint

Keywords

  • Degradation
  • Dithionite
  • HMX
  • RDX
  • Sediments
  • TNT

ASJC Scopus subject areas

  • Environmental Engineering
  • Environmental Chemistry
  • Chemistry(all)
  • Pollution
  • Health, Toxicology and Mutagenesis

Cite this