Hydrocarbon vapor diffusion in intact core sleeves

Journal Article · · Ground Water Monitoring and Remediation; (United States)

DOI:https://doi.org/10.1111/j.1745-6592.1993.tb00431.x· OSTI ID:6315118

Ostendorf, D W; Moyer, E E; Xie, Yuefeng; Rajan, R V ^[1]

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1. Univ. of Massachusetts, Amherst, MA (United States). Civil Engineering Dept.

The diffusion of 2,2,4-trimethylpentane (TMP) and 2,2,5-trimethylhexane (TMH) vapors out of residually contaminated sandy soil from the US Environmental Protection Agency (EPA) field research site at Traverse City, Michigan, was measured and modeled. The headspace of an intact core sleeve sample was swept with nitrogen gas to simulate the diffusive release of hydrocarbon vapors from residual aviation gasoline in and immediately above the capillary fringe to a soil-venting air flow in the unsaturated zone. The resulting steady-state profile was modeled using existing diffusivity and air porosity estimates in a balance of diffusive flux and a first order source term. The source strength, which was calibrated with the observed flux of 2,2,4-TMP leaving the sleeve, varied with the residual gasoline remaining in the core, but was independent of the headspace sweep flow rate. This finding suggested that lower soil-venting air flow rates were in principle as effective as higher air flow rates in venting LNAPL vapors from contaminated soils. The saturated vapor concentration ratio of 2,2,4-TMP to 2,2,5-TMH decreased from 6.6 to 3.5 over the duration of the experiments in an expression of distillation effects. The vertical profile model was tested against sample port data in four separate experiments for both species, yielding mean errors ranging from 0 to [minus]24% in magnitude.

• OSTI ID: 6315118
• Journal Information: Ground Water Monitoring and Remediation; (United States), Journal Name: Ground Water Monitoring and Remediation; (United States) Vol. 13:1; ISSN XZ212O
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020900* -- Petroleum-- Environmental Aspects
54 ENVIRONMENTAL SCIENCES
540220 -- Environment
Terrestrial-- Chemicals Monitoring & Transport-- (1990-)
AIR FLOW
CONTAMINATION
DEVELOPED COUNTRIES
ENVIRONMENTAL TRANSPORT
FLUID FLOW
FLUIDS
FUELS
GAS FLOW
GASES
GASOLINE
HYDROCARBONS
LIQUID FUELS
MASS TRANSFER
MATHEMATICAL MODELS
MICHIGAN
NORTH AMERICA
ORGANIC COMPOUNDS
PETROLEUM PRODUCTS
POLLUTION
SAMPLING
SOILS
USA
VAPORS
WATER POLLUTION