Effects of natural organic matter, anthropogenic surfactants, and model quinones on the reduction of contaminants by zero-valent iron

Paul G. Tratnyek, Michelle M. Scherer, Baolin Deng, Shaodong Hu

Research output: Contribution to journalArticle

171 Scopus citations

Abstract

Recent studies of contaminant reduction by zero-valent iron metal (Fe0) have highlighted the role of iron oxides at the metal-water interface and the effect that sorption has at the oxide-water interface on contaminant reduction kinetics. The results suggest that a variety of organic surface-active substances might enhance or inhibit contaminant degradation, depending on the degree to which they promote solubilization, sorption, and/or reaction. Of particular interest is the effect of natural organic matter (NOM), because of its ubiquitous presence in natural waters and amphiphilic properties; anthropogenic surfactants, because of their use in groundwater remediation; and certain quinones, which represent the redox-active functional groups associated with NOM. In this study, no well-defined effects of these substances were found on the reduction of nitro benzene by Fe0, but the reduction of carbon tetrachloride and trichloroethylene (TCE) was inhibited by NOM. Results with carbon tetrachloride showed that the inhibitory effect of humic acids was greater than fulvic acids, but that several quinonoid NOM model compounds (juglone, lawsone, and anthraquinone disulfonate) increased the rate of reduction by Fe0. Isotherms for adsorption of TCE and NOM onto Fe0 showed evidence of competition for surface sites.

Original languageEnglish (US)
Pages (from-to)4435-4443
Number of pages9
JournalWater Research
Volume35
Issue number18
DOIs
StatePublished - Jan 1 2001

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Keywords

  • Adsorption
  • Fulvic acid
  • Humic acid
  • Permeable reactive barriers
  • Quinones
  • Surfactants
  • Zero-valent iron

ASJC Scopus subject areas

  • Ecological Modeling
  • Water Science and Technology
  • Waste Management and Disposal
  • Pollution

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