+ Site Statistics
References:
54,258,434
Abstracts:
29,560,870
PMIDs:
28,072,757
+ Search Articles
+ PDF Full Text Service
How our service works
Request PDF Full Text
+ Follow Us
Follow on Facebook
Follow on Twitter
Follow on LinkedIn
+ Subscribe to Site Feeds
Most Shared
PDF Full Text
+ Translate
+ Recently Requested

Transient multicomponent gas-phase transport of volatile organic chemicals in porous media



Transient multicomponent gas-phase transport of volatile organic chemicals in porous media



Journal of Environmental Quality 25(5): 1041-1047



Liquid mixtures of volatile organic chemicals (VOCs) contaminating many soil and groundwater sites give rise to multicomponent mixtures of their vapors. Column studies were conducted to characterize multicomponent diffusive transport of TCE and benzene vapors through air-dry sand. The vapors diffused from their liquid mixture source at one end of the column to the other end where their concentration was maintained at zero by flowing clean air across the column. Simulations based on Stefan-Maxwell equations of vapor diffusion predicted that the TCE and benzene multicomponent steady-state flux densities should be 6.7 and 5.5% higher than the predictions based on Fick's law, respectively. The measured steady-state multicomponent mass flux densities were higher than Fick's law estimates by 4.5 to 10.6 and 3.9 to 10.0% for TCE and benzene, respectively. These results show that multicomponent equations should be used to predict the steady-state flux densities in a multicomponent VOC vapor mixture. During the transient phase of the experiments, use of Fick's law led to adequate predictions of flux density and concentration. A transient transport model based on Fick's law and a multicomponent, nonlinear adsorption model predicted measured TCE and benzene concentrations along the column in both experiments more accurately than a model based on a single-species linear isotherm, which underpredicted vapor concentrations for both species. The magnitude of the underestimation was less for benzene, which is less strongly adsorbed at low concentrations than TCE. The linear adsorption isotherm adequately predicted concentrations at the early stages of the experiment when low concentrations were predominant.

Please choose payment method:






(PDF emailed within 0-6 h: $19.90)

Accession: 003001055

Download citation: RISBibTeXText

DOI: 10.2134/jeq1996.00472425002500050016x


Related references

Effect of dynamic competitive sorption on the transport of volatile organic chemicals through dry porous media. Water Resources Research 35(5): 1347-1359, 1999

Modeling multicomponent organic chemical transport in three fluid phase porous media. Journal of Contaminant Hydrology 5(4): 349-374, 1990

Transport and fate of volatile organic chemicals in unsaturated, nonisothermal, salty porous media: 1. Theoretical development. Journal of Hazardous Materials 69(2): 151-167, Oct 29, 1999

Transport and fate of volatile organic chemicals in unsaturated, nonisothermal, salty porous media: 2. Experimental and numerical studies for benzene. Journal of Hazardous Materials 69(2): 169-185, Oct 29, 1999

Influence of air-water interfacial adsorption and gas-phase partitioning on the transport of organic chemicals in unsaturated porous media. Environmental Science and Technology 32(9): 1253-1259, 1998

Volatile organic compounds volatilization from multicomponent organic liquids and diffusion in unsaturated porous media. Vadose zone journal VZJ 2(4), 2003

Diffusion of Volatile Organic Chemicals in Porous Media. 2. Alcohol/Templated Porous Carbon Systems. Energy & Fuels 20(3): 1269-1274, 2006

Gaseous transport of volatile organic chemicals in unsaturated porous media: effect of water-partitioning and air-water interfacial adsorption. Environmental Science and Technology 35(22): 4457-4462, 2001

Diffusion of Volatile Organic Chemicals in Porous Media. 1. Alcohol/Natural Zeolite Systems. Energy & Fuels 19(6): 2219-2224, 2005

Transport of volatile compounds in porous media in the presence of a trapped gas phase. Journal of Contaminant Hydrology 49(3-4): 263-285, 2001

Density and pressure effects on the transport of gas phase chemicals in unsaturated porous media. Water Resources Research 39(3): SBH 8/1-SBH 8/11, 2003

Modeling transient organic vapor transport in porous media with the dusty gas model. Advances in water resources, 22(3): 247-256, 1998

Biodegradation of volatile organic compounds in porous media with natural and forced gas-phase advection. Pages 245-261:, 1991

Evaluation of effective parameters for volatile organic compounds in porous media with mobile air phase. Transport in Porous Media 63(2): 349-362, 2006

Transport of dissolved contaminants originating from a rectangular prism-shaped, multicomponent nonaqueous-phase liquid source in saturated porous media. Environmental geology 43(1-2): 132-137, 2002