Dense Nonaqueous Phase Liquids (DNAPLs)Chromium VI
Dense Nonaqueous Phase Liquids (DNAPLs)
1,4-Dioxane
Mercury
MTBE
Perchlorate
POPs
PCBs
TCE
Other Contaminants
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Chemistry and Behavior
The purpose of this section is to identify documents, preferably online, that describe the chemical properties of DNAPLs and their fate and transport in the environment. DNAPL chemicals have a very broad range of chemical properties that make them difficult to group and these differences in chemical properties gives them very different fates. For example trichloroethene (TCE) is less viscous than water, will move readily through a permeable subsurface, can be anaerobically degraded under the proper conditions, and does not bioaccumulate in fauna. Polychlorinated byphenyls (PCBs) on the other hand, are much more viscous than water (up to 700 times for 1254 blend) and hence do not move as quickly through permeable soils as TCE. Unlike TCE, PCBs also bioaccumulate and biomagnify and have caused substantial damage to aquatic food chains.
This part of this section identifies general documents on DNAPL chemical properties and fate and transport mechanisms. Cohen and Mercer (EPA 1993) also contains a summary table with selected data on DNAPL chemicals (Table A-1
). Documents on characteristics specific to a chemical class can be found in the subsections listed to the right. A general discussion of DNAPL movement in the subsurface can be found in the Overview and Treatment Technologies sections.
Cohen, R. and J. Mercer. 1993. DNAPL Site Evaluation, EPA 600/R-93/022. Office of Research and Development, U.S. EPA.
General DNAPL Chemistry and Behavior Documents
An Illustrated Handbook of DNAPL Transport and Fate in the Subsurface
Environment Agency, United Kingdom
R&D Publication 133, 2003
This publication provides an overview of DNAPLs, their fate and transport, characterization and remedial approaches, and appendices on specific issues such as the aperture required to stop DNAPL migration in fractured rock.
DNAPL and LNAPL Distributions in Soils; Experimental and Modeling Studies
Durnford, D., D. McWhorter, C. Miller, A. Swanson, F. Marinelli, and H. Trantham
October 1997, Report No.: AFRL-SR-BL-TR-98, NTIS: ADA342524
This report examines the subtle aspects of immiscible fluid behavior that can be manifested in large scale effects. It presents a method for modeling one-dimensional, multiphase flow through layered media. Finally it presents details on a two-dimensional pore scale model based on modified diffusion limited aggregation algorithm.
DNAPLs in Groundwater
University of Sheffield
A web-based introduction to the physical/chemical properties of DNAPLs and their movement in the subsurface. Also addresses other DNAPL issues such as characterization and remediation.
DNAPL Site Evaluation
Cohen, R. and J. Mercer. 1993.
EPA 600/R-93/022. Office of Research and Development, U.S. EPA
While dated, this publication has an extensive discussion on the theoretical aspects of DNAPL flow in saturated and unsaturated media. It provides a good basis for understanding why DNAPL source zones can form complex architectures.
Role of Aquitards in the Protection of Aquifers from Contamination: A “State of the Science” Report
Cherry, J., B. Parker, K. Bradbury, T. Eaton, M. Gotkowitz, D. Hart, and M.A. Borchardt
AWWA Research Foundation, 2004
This report discusses the flow of contaminated water and DNAPLs in aquitards and the forces that allow or prevent their penetrating into an underlying water supply.
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Chemistry_and_Behavior/
Last updated on Thursday, July 24, 2008