Vapor transport in unsaturated soil columns: implications for vapor extraction

A mathematical model was derived to examine the impact of gas advection, gas diffusion, gas-water mass transfer, gas-water partitioning, sorption, and intraaggregate diffusion on subsurface movement of organic vapors. Laboratory experiments were performed to determine the validity of the model and t...

Full description

Saved in:
Bibliographic Details
Published in:Water resources research 1992-02, Vol.28 (2), p.323-335
Main Authors: Gierke, J.S. (Michigan Technological University, Houghton), Hutzler, N.J, McKenzie, D.B
Format: Article
Language:English
Subjects:
540220 - Environment, Terrestrial- Chemicals Monitoring & Transport- (1990-)
ALKYLATED AROMATICS
ARENA
AROMATICS
CONTAMINANTES
CONTAMINATION
ENVIRONMENTAL SCIENCES
Environmental Sciences & Ecology
ENVIRONMENTAL TRANSPORT
EXTRACTION
FLUIDS
GASES
GAZ
HYDROCARBONS
Life Sciences & Biomedicine
Limnology
Marine & Freshwater Biology
MASS TRANSFER
MATHEMATICAL MODELS
MATTER
METANO
METHANE
MODELE MATHEMATIQUE
MODELOS MATEMATICOS
ORGANIC COMPOUNDS
Physical Sciences
POLLUANT
POLLUTION DU SOL
POLUCION DEL SUELO
PROCESOS DE TRANSPORTE EN EL SUELO
REMEDIAL ACTION
SABLE
Science & Technology
SEPARATION PROCESSES
SOILS
SORPTION
TOLUENE
TOLUENO
TRANSPORT DANS LE SOL
UNIDADES ESTRUCTURALES DE SUELOS
UNITE STRUCTURALE DU SOL
VAPORS
VOLATILE MATTER
Water Resources
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:A mathematical model was derived to examine the impact of gas advection, gas diffusion, gas-water mass transfer, gas-water partitioning, sorption, and intraaggregate diffusion on subsurface movement of organic vapors. Laboratory experiments were performed to determine the validity of the model and to investigate the impact of the various mechanisms on vapor transport, Columns were packed with a uniform Ottawa sand and an aggregated porous soil material (APSM) to compare transport in different soil structures. Toluene vapor transport was observed in the sand under dry and wet (27% water saturation) conditions. The experiments with the APSM were performed dry and at 67% water saturation. in all the sand and the dry APSM experiments, gas advection and diffusion had the greatest impact. In a wet APSM experiment, intraaggregate (liquid) diffusion was also important to consider for gas velocities greater than approximately 0.05 cm s-1. For both soil materials, sorption of toluene vapors occurred for dry conditions, while vapor sorption was negligible when liquid water was present. These findings imply that vapor extraction performance in moist, aggregated soils will be affected by nonequilibrium transport. Therefore models that are developed for predicting the complete removal of contaminants by vapor extraction must account for nonequilibrium
ISSN:0043-1397
1944-7973
DOI:10.1029/91WR02661