Hydrocarbon vapor transport in low moisture soils

Journal Article · Sun Jan 01 04:00:00 EST 1995 · Environmental Science and Technology; (United States)

DOI:https://doi.org/10.1021/es00001a022· OSTI ID:6591739

Batterman, S; Kulshrestha, A; Cheng, H Y ^[1]

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1. Univ. of Michigan, Ann Arbor, MI (United States)

Gas-phase transport of hydrocarbons in unsaturated soils is important in the assessment and remediation of volatile subsurface contaminants and other environmental applications. This paper presents models and measurements of diffusion, dispersion, and retardation parameters developed for several hydrocarbon vapors in unsaturated soils using laboratory column systems. Diffusion coefficients are determined in dry soils using steady-state methods. Retardation and dispersion parameters are found using transient methods and a range of soil moisture contents below the saturation soil moisture content. Media tested included sand, fill, loam, and glass beads as controls; contaminants included toluene, trichlorethylene, and methane. The experiments clearly demonstrate the role of humidity in absorption and transport of vapors in soils. Soil gas humidities below 30% result in considerable retardation of hydrocarbon vapors in all media. Retardation factors range up to 80 for toluene and to 46 for trichloroethylene. Retardation coefficients decrease but remain large with increasing humidity in organic-rich soils. No significant retardation is seen for methane. Based on soil-water isotherms, these results suggest competitive sorption between hydrocarbon and water vapors on soil surfaces, especially the mineral fraction. 36 refs., 5 figs., 5 tabs.

• OSTI ID: 6591739
• Journal Information: Environmental Science and Technology; (United States), Journal Name: Environmental Science and Technology; (United States) Vol. 29:1; ISSN ESTHAG; ISSN 0013-936X
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201 -- Chemical & Physicochemical Properties
54 ENVIRONMENTAL SCIENCES
540220* -- Environment
Terrestrial-- Chemicals Monitoring & Transport-- (1990-)
ABSORPTION
ALKYLATED AROMATICS
AROMATICS
DATA
DIFFUSION
ENVIRONMENTAL TRANSPORT
EXPERIMENTAL DATA
FLUIDS
GASES
HUMIDITY
HYDROCARBONS
INFORMATION
MASS TRANSFER
MATTER
MOISTURE
NUMERICAL DATA
ORGANIC COMPOUNDS
SOILS
SORPTION
TOLUENE
TRANSPORT THEORY
VAPORS
VOLATILE MATTER
WATER VAPOR