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Title: Dehalogenation of chlorinated organic compounds by strong alkalis

Abstract

Chlorinated organic compounds such as trichloroethylene (TCE) are the most prevalent contaminants found in soil and ground water, and pose serious health risks even at trace concentrations. This research reports a new chemical treatment technique for rapid degradation of TCE in strong alkaline solutions. Batch kinetic reactions between TCE and NaOH indicate that TCE can be rapidly and completely dechlorinated in NaOH at elevated temperatures. The reaction can be described by a pseudo-first-order rate kinetics with an estimated activation energy of {approximately}85 kJ/mol. The half-lives for TCE degradation in 2M NaOH at 40, 60, 80, and 100 C were approximately 347, 48.8, 4.0, and 2.4 min, respectively. The reaction end-products are primarily Cl{sup {minus}} anions and Na-glycollate, both of which are nonhazardous. This treatment technique is applicable for degrading other halogenated organic compounds wherein a nucleophilic substitution or elimination is the major reaction mechanism or pathway. Potential applications of this technology include the removal and destruction of vapor-phase chlorinated volatile organic compounds (VOCs) in off-gases when soil vapor extraction or air-stripping techniques are used for remediating VOC-contaminated soils and ground water. A bench-scale alkaline destruction module was tested, and results indicated that {approximately}90% of TCE was destroyed when TCE vapormore » (10 mg/L) was passed through a destruction column with a retention time of {approximately}1 min at 95 C.« less

Authors:
 [1];  [2]
  1. Oak Ridge National Lab., TN (United States)
  2. Oak Ridge National Lab./Colorado School of Mines, Golden, CO (United States)
Publication Date:
Sponsoring Org.:
USDOE
OSTI Identifier:
544105
DOE Contract Number:  
AC05-96OR22464
Resource Type:
Journal Article
Journal Name:
Journal of Environmental Engineering
Additional Journal Information:
Journal Volume: 123; Journal Issue: 10; Other Information: PBD: Oct 1997
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; CHLORINATED ALIPHATIC HYDROCARBONS; REMEDIAL ACTION; SOILS; GROUND WATER; PERFORMANCE TESTING; BENCH-SCALE EXPERIMENTS; DECHLORINATION; SODIUM HYDROXIDES

Citation Formats

Gu, B, and Siegrist, R L. Dehalogenation of chlorinated organic compounds by strong alkalis. United States: N. p., 1997. Web. doi:10.1061/(ASCE)0733-9372(1997)123:10(982).
Gu, B, & Siegrist, R L. Dehalogenation of chlorinated organic compounds by strong alkalis. United States. https://doi.org/10.1061/(ASCE)0733-9372(1997)123:10(982)
Gu, B, and Siegrist, R L. 1997. "Dehalogenation of chlorinated organic compounds by strong alkalis". United States. https://doi.org/10.1061/(ASCE)0733-9372(1997)123:10(982).
@article{osti_544105,
title = {Dehalogenation of chlorinated organic compounds by strong alkalis},
author = {Gu, B and Siegrist, R L},
abstractNote = {Chlorinated organic compounds such as trichloroethylene (TCE) are the most prevalent contaminants found in soil and ground water, and pose serious health risks even at trace concentrations. This research reports a new chemical treatment technique for rapid degradation of TCE in strong alkaline solutions. Batch kinetic reactions between TCE and NaOH indicate that TCE can be rapidly and completely dechlorinated in NaOH at elevated temperatures. The reaction can be described by a pseudo-first-order rate kinetics with an estimated activation energy of {approximately}85 kJ/mol. The half-lives for TCE degradation in 2M NaOH at 40, 60, 80, and 100 C were approximately 347, 48.8, 4.0, and 2.4 min, respectively. The reaction end-products are primarily Cl{sup {minus}} anions and Na-glycollate, both of which are nonhazardous. This treatment technique is applicable for degrading other halogenated organic compounds wherein a nucleophilic substitution or elimination is the major reaction mechanism or pathway. Potential applications of this technology include the removal and destruction of vapor-phase chlorinated volatile organic compounds (VOCs) in off-gases when soil vapor extraction or air-stripping techniques are used for remediating VOC-contaminated soils and ground water. A bench-scale alkaline destruction module was tested, and results indicated that {approximately}90% of TCE was destroyed when TCE vapor (10 mg/L) was passed through a destruction column with a retention time of {approximately}1 min at 95 C.},
doi = {10.1061/(ASCE)0733-9372(1997)123:10(982)},
url = {https://www.osti.gov/biblio/544105}, journal = {Journal of Environmental Engineering},
number = 10,
volume = 123,
place = {United States},
year = {Wed Oct 01 00:00:00 EDT 1997},
month = {Wed Oct 01 00:00:00 EDT 1997}
}