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Title: Degradation of TCE with iron: The role of competing chromate and nitrate reduction

Abstract

This study evaluates the potential of using granular iron metal for the abiotic removal of the organic ground water pollutant trichloroethene (TCE) in the presence of the common inorganic co-contaminants chromate and nitrate, respectively. Their long-term column experiments indicate a competitive process between TCE dechlorination and reductive transformation of chromate and nitrate, which is reflected in a significantly delayed onset of TCE dechlorination. Delay times and therefore the ranges of the nonreactive flowpaths increased with increasing experimental duration, resulting in a migration of the contaminants through the iron metal treatment zone. The present investigation also indicates that the calculated migration rates of TCE and the added cocontaminants chromate and nitrate are linearly related to the initial content of the cocontaminants. With an average pore water velocity of 0.6 m/d and a surface area concentration of 0.55 m{sup 2}/mL in the column, the calculated migration rates varied between 0.10 cm/d and 5.86 cm/d. The particular similarity between the values of TCE migration and the migration of the strong oxidants chromate and nitrate and the long-term steady state of the TCE dechlorination in the absence of the chromate and nitrate indicates that these competitive transformations are the driving force for the gradualmore » passivation of the granular iron due to the buildup of an electrically insulating Fe(III)-oxyhydroxide. Based on these passivation processes, general formulae were developed that allow a simplified approximation of breakthrough times for the contaminants TCE, chromate, and nitrate.« less

Authors:
; ; ; ; ;
Publication Date:
Research Org.:
Eifelstrasse, Frankfurt (DE)
OSTI Identifier:
20080439
Alternate Identifier(s):
OSTI ID: 20080439
Resource Type:
Journal Article
Journal Name:
Ground Water
Additional Journal Information:
Journal Volume: 38; Journal Issue: 3; Other Information: PBD: May-Jun 2000; Journal ID: ISSN 0017-467X
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; REMEDIAL ACTION; GROUND WATER; CHLORINATED ALIPHATIC HYDROCARBONS; IRON; CHROMATES; NITRATES; REDUCTION; WATER CHEMISTRY; ENVIRONMENTAL TRANSPORT

Citation Formats

Schlicker, O., Ebert, M., Fruth, M., Weidner, M., Wuest, W., and Dahmke, A. Degradation of TCE with iron: The role of competing chromate and nitrate reduction. United States: N. p., 2000. Web. doi:10.1111/j.1745-6584.2000.tb00226.x.
Schlicker, O., Ebert, M., Fruth, M., Weidner, M., Wuest, W., & Dahmke, A. Degradation of TCE with iron: The role of competing chromate and nitrate reduction. United States. doi:10.1111/j.1745-6584.2000.tb00226.x.
Schlicker, O., Ebert, M., Fruth, M., Weidner, M., Wuest, W., and Dahmke, A. Thu . "Degradation of TCE with iron: The role of competing chromate and nitrate reduction". United States. doi:10.1111/j.1745-6584.2000.tb00226.x.
@article{osti_20080439,
title = {Degradation of TCE with iron: The role of competing chromate and nitrate reduction},
author = {Schlicker, O. and Ebert, M. and Fruth, M. and Weidner, M. and Wuest, W. and Dahmke, A.},
abstractNote = {This study evaluates the potential of using granular iron metal for the abiotic removal of the organic ground water pollutant trichloroethene (TCE) in the presence of the common inorganic co-contaminants chromate and nitrate, respectively. Their long-term column experiments indicate a competitive process between TCE dechlorination and reductive transformation of chromate and nitrate, which is reflected in a significantly delayed onset of TCE dechlorination. Delay times and therefore the ranges of the nonreactive flowpaths increased with increasing experimental duration, resulting in a migration of the contaminants through the iron metal treatment zone. The present investigation also indicates that the calculated migration rates of TCE and the added cocontaminants chromate and nitrate are linearly related to the initial content of the cocontaminants. With an average pore water velocity of 0.6 m/d and a surface area concentration of 0.55 m{sup 2}/mL in the column, the calculated migration rates varied between 0.10 cm/d and 5.86 cm/d. The particular similarity between the values of TCE migration and the migration of the strong oxidants chromate and nitrate and the long-term steady state of the TCE dechlorination in the absence of the chromate and nitrate indicates that these competitive transformations are the driving force for the gradual passivation of the granular iron due to the buildup of an electrically insulating Fe(III)-oxyhydroxide. Based on these passivation processes, general formulae were developed that allow a simplified approximation of breakthrough times for the contaminants TCE, chromate, and nitrate.},
doi = {10.1111/j.1745-6584.2000.tb00226.x},
journal = {Ground Water},
issn = {0017-467X},
number = 3,
volume = 38,
place = {United States},
year = {2000},
month = {6}
}