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Title: Single event-driven export of polycyclic aromatic hydrocarbons and suspended matter from coal tar-contaminated soil

Abstract

Mobile colloidal and suspended matter is likely to affect the mobility of polycyclic aromatic hydrocarbons (PAHs) in the unsaturated soil zone at contaminated sites. We studied the release of mobile particles and dissolved organic matter as a function of variable climatic boundary conditions, and their effect on the export of PAHs at a coal tar-contaminated site using zero-tension lysimeters. Seepage water samples were analyzed for dissolved organic carbon (DOC), pH, electrical conductivity, turbidity, and particles larger than 0.7 {mu}m. The 16 Environmental Protection Agency PAHs were analyzed in the filtrate < 0.7 m and in the particle fraction. Our results show that extended no-flow periods that are followed by high-intensity rain events, such as thunderstorms, promote the mobilization of particles in the size 0.7 to 200 m. Mobilization is enforced by extended drying during summer. High particle concentrations are also associated with freezing and thawing cycles followed by either rain or snowmelt events. The export of PAHs is strongly connected to the release of particles in the 0.7- to 200-{mu}m size fraction. During the 2-yr monitoring period, up to 0.418 {mu}g kg{sup -1} PAHs were mobilized in the. ltrate (< 0.7 m) while the eightfold mass, 3.36 {mu}g kg{sup -1},more » was exported with the retentate (0.7-200 {mu}m). Equilibrium dissolution of PAHs and transport in the dissolved phase seem to be of minor importance for the materials studied. Extreme singular-release events occurred in January 2003 and January 2004, when up to 55 {mu}g L{sup -1} PAHs per one single seepage event were observed within the retentate. Freezing and thawing cycles affect the PAH source materials, that is, the remnants of the nonaqueous phase liquid (NAPL). High mechanical strain during freezing results in the formation of particles. At the onset of the thawing and following rain or snowmelt events, PAHs associated with these particles are then exported from the lysimeter.« less

Authors:
; ;  [1]
  1. University of Jena, Jena (Germany)
Publication Date:
OSTI Identifier:
20969791
Resource Type:
Journal Article
Resource Relation:
Journal Name: Vadose Zone Journal; Journal Volume: 6; Journal Issue: 2
Country of Publication:
United States
Language:
English
Subject:
01 COAL, LIGNITE, AND PEAT; POLYCYCLIC AROMATIC HYDROCARBONS; SOILS; COAL TAR; CONTAMINATION; PARTICLES; ORGANIC MATTER; WATER POLLUTION; MOBILITY; ENVIRONMENTAL TRANSPORT

Citation Formats

Totsche, K.U., Jann, S., and Kogel-Knabner, I.. Single event-driven export of polycyclic aromatic hydrocarbons and suspended matter from coal tar-contaminated soil. United States: N. p., 2007. Web. doi:10.2136/vzj2006.0083.
Totsche, K.U., Jann, S., & Kogel-Knabner, I.. Single event-driven export of polycyclic aromatic hydrocarbons and suspended matter from coal tar-contaminated soil. United States. doi:10.2136/vzj2006.0083.
Totsche, K.U., Jann, S., and Kogel-Knabner, I.. Tue . "Single event-driven export of polycyclic aromatic hydrocarbons and suspended matter from coal tar-contaminated soil". United States. doi:10.2136/vzj2006.0083.
@article{osti_20969791,
title = {Single event-driven export of polycyclic aromatic hydrocarbons and suspended matter from coal tar-contaminated soil},
author = {Totsche, K.U. and Jann, S. and Kogel-Knabner, I.},
abstractNote = {Mobile colloidal and suspended matter is likely to affect the mobility of polycyclic aromatic hydrocarbons (PAHs) in the unsaturated soil zone at contaminated sites. We studied the release of mobile particles and dissolved organic matter as a function of variable climatic boundary conditions, and their effect on the export of PAHs at a coal tar-contaminated site using zero-tension lysimeters. Seepage water samples were analyzed for dissolved organic carbon (DOC), pH, electrical conductivity, turbidity, and particles larger than 0.7 {mu}m. The 16 Environmental Protection Agency PAHs were analyzed in the filtrate < 0.7 m and in the particle fraction. Our results show that extended no-flow periods that are followed by high-intensity rain events, such as thunderstorms, promote the mobilization of particles in the size 0.7 to 200 m. Mobilization is enforced by extended drying during summer. High particle concentrations are also associated with freezing and thawing cycles followed by either rain or snowmelt events. The export of PAHs is strongly connected to the release of particles in the 0.7- to 200-{mu}m size fraction. During the 2-yr monitoring period, up to 0.418 {mu}g kg{sup -1} PAHs were mobilized in the. ltrate (< 0.7 m) while the eightfold mass, 3.36 {mu}g kg{sup -1}, was exported with the retentate (0.7-200 {mu}m). Equilibrium dissolution of PAHs and transport in the dissolved phase seem to be of minor importance for the materials studied. Extreme singular-release events occurred in January 2003 and January 2004, when up to 55 {mu}g L{sup -1} PAHs per one single seepage event were observed within the retentate. Freezing and thawing cycles affect the PAH source materials, that is, the remnants of the nonaqueous phase liquid (NAPL). High mechanical strain during freezing results in the formation of particles. At the onset of the thawing and following rain or snowmelt events, PAHs associated with these particles are then exported from the lysimeter.},
doi = {10.2136/vzj2006.0083},
journal = {Vadose Zone Journal},
number = 2,
volume = 6,
place = {United States},
year = {Tue May 15 00:00:00 EDT 2007},
month = {Tue May 15 00:00:00 EDT 2007}
}
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