Vacuum photocatalytic oxidation of trichloroethylene

Rao Annapragada, Robert Leet, Rajnish Changrani, Gregory Raupp

Research output: Contribution to journalArticle

14 Citations (Scopus)

Abstract

The combination of physical removal methods such as soil vapor vacuum extraction or vacuum air stripping with gas-solid heterogeneous photocatalytic oxidation of the off-gases produced may be an effective remediation technology for a variety of soil and water contamination problems, particularly those involving chlorinated ethylenes. To test the hypothesis that reduced pressure operation of the photocatalytic unit could enhance reactor performance, a bench-scale annular photocatalytic reactor operating in the vacuum range was designed, built, and evaluated. The reactor inner wall was coated with sol-gel-derived titania to provide a uniform, adherent, photocatalytically active thin film. Photocatalytic oxidation of trichloroethylene (TCE) in humid airstreams was employed as a model chemistry. Reduction of the operating pressure at fixed feed conditions and molar feed rate significantly enhanced PCO performance as measured by the observed TCE conversion. Higher conversions were obtained in spite of a reduction in the residence time accompanying the lower pressure operation. The greatest enhancements in the TCE destruction efficiency occurred for low TCE feed concentrations and high water vapor levels. The performance enhancement appears to be linked to reduction in the absolute water vapor concentration and competition between TCE and water vapor for adsorption sites on the catalyst.

Original languageEnglish (US)
Pages (from-to)1898-1901
Number of pages4
JournalEnvironmental Science and Technology
Volume31
Issue number7
DOIs
StatePublished - Jul 1997

Fingerprint

Trichloroethylene
trichloroethylene
Vacuum
Steam
oxidation
Oxidation
Water vapor
water vapor
Ethylenes
Gases
Soils
Remediation
gas
ethylene
titanium
Sol-gels
low pressure
residence time
Ethylene
remediation

ASJC Scopus subject areas

  • Environmental Science(all)
  • Environmental Chemistry
  • Environmental Engineering

Cite this

Vacuum photocatalytic oxidation of trichloroethylene. / Annapragada, Rao; Leet, Robert; Changrani, Rajnish; Raupp, Gregory.

In: Environmental Science and Technology, Vol. 31, No. 7, 07.1997, p. 1898-1901.

Research output: Contribution to journalArticle

Annapragada, Rao ; Leet, Robert ; Changrani, Rajnish ; Raupp, Gregory. / Vacuum photocatalytic oxidation of trichloroethylene. In: Environmental Science and Technology. 1997 ; Vol. 31, No. 7. pp. 1898-1901.
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