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Title: Enhanced TEX biodegradation in nutrient briquet-peat barrier system

Abstract

A two-layer barrier system has been developed to remediate gasoline-contaminated ground water. This system consists of a nutrient briquet layer to continuously supply nitrate as the electron acceptor for contaminant biodegradation and a peat layer to remove residual nitrate via biological denitrification and residual contaminants by sorption. Nitrate release rates from three different sizes of concrete briquets were used to estimate parameters for modeling solute diffusion in aggregated porous media with mobile and stagnant porewater regions. Toluene, ethylbenzene, and xylene (TEX) biodegradation rates in denitrifying microcosms at pH 8 and 9 were lower than in microcosms at pH 7.4. No degradation was observed at pH 10 under denitrifying conditions. A laboratory-scale, permeable barrier system was developed to evaluate TEX removal and to identify any operational problems. Average removal efficiencies were 86% for toluene, 71% for ethylbenzene, 43% for m-xylene, and 28% for o-xylene in the nutrient briquet and downstream soil column over a 45-day operating period. There was no evidence of benzene biodegradation under denitrifying conditions in the batch microcosms or continuous-flow columns.

Authors:
 [1];  [2]
  1. Geophex, Ltd., Raleigh, NC (United States)
  2. North Carolina State Univ., Raleigh, NC (United States). Civil Engineering Dept.
Publication Date:
Sponsoring Org.:
Environmental Protection Agency, Washington, DC (United States)
OSTI Identifier:
419593
Resource Type:
Journal Article
Journal Name:
Journal of Environmental Engineering
Additional Journal Information:
Journal Volume: 123; Journal Issue: 1; Other Information: PBD: Jan 1997
Country of Publication:
United States
Language:
English
Subject:
02 PETROLEUM; GROUND WATER; REMEDIAL ACTION; ALKYLATED AROMATICS; BIODEGRADATION; CONTAINMENT SYSTEMS; DESIGN; OIL SPILLS; TOLUENE; XYLENES; ENVIRONMENTAL TRANSPORT

Citation Formats

Kao, C M, and Borden, R C. Enhanced TEX biodegradation in nutrient briquet-peat barrier system. United States: N. p., 1997. Web. doi:10.1061/(ASCE)0733-9372(1997)123:1(18).
Kao, C M, & Borden, R C. Enhanced TEX biodegradation in nutrient briquet-peat barrier system. United States. https://doi.org/10.1061/(ASCE)0733-9372(1997)123:1(18)
Kao, C M, and Borden, R C. Wed . "Enhanced TEX biodegradation in nutrient briquet-peat barrier system". United States. https://doi.org/10.1061/(ASCE)0733-9372(1997)123:1(18).
@article{osti_419593,
title = {Enhanced TEX biodegradation in nutrient briquet-peat barrier system},
author = {Kao, C M and Borden, R C},
abstractNote = {A two-layer barrier system has been developed to remediate gasoline-contaminated ground water. This system consists of a nutrient briquet layer to continuously supply nitrate as the electron acceptor for contaminant biodegradation and a peat layer to remove residual nitrate via biological denitrification and residual contaminants by sorption. Nitrate release rates from three different sizes of concrete briquets were used to estimate parameters for modeling solute diffusion in aggregated porous media with mobile and stagnant porewater regions. Toluene, ethylbenzene, and xylene (TEX) biodegradation rates in denitrifying microcosms at pH 8 and 9 were lower than in microcosms at pH 7.4. No degradation was observed at pH 10 under denitrifying conditions. A laboratory-scale, permeable barrier system was developed to evaluate TEX removal and to identify any operational problems. Average removal efficiencies were 86% for toluene, 71% for ethylbenzene, 43% for m-xylene, and 28% for o-xylene in the nutrient briquet and downstream soil column over a 45-day operating period. There was no evidence of benzene biodegradation under denitrifying conditions in the batch microcosms or continuous-flow columns.},
doi = {10.1061/(ASCE)0733-9372(1997)123:1(18)},
url = {https://www.osti.gov/biblio/419593}, journal = {Journal of Environmental Engineering},
number = 1,
volume = 123,
place = {United States},
year = {1997},
month = {1}
}