Water Resources Research

Analytical solutions for the transport of volatile organic chemicals in unsaturated layered systems

Authors

  • S. R. Yates,

  • S. K. Papiernik,

  • F. Gao,

  • J. Gan


Abstract

Several analytical solutions were developed that describe the transport of volatile organic chemicals or other gases in layered porous media. Solutions are presented for a one-dimensional system consisting of either two finite soil layers or a finite layer adjacent to an infinite soil layer. The proposed solutions may be useful for studying the movement of volatile chemicals or other gases in layered soils, as well as for gas movement from soils into passive flux chambers, which are commonly used for measuring the surface volatilization rate. The behavior of the solutions is illustrated by several examples showing the soil gas concentration and the flux density as a function of time. At early times it was found that the flux density into a chamber is relatively constant when the mass transfer coefficient h is small. However, the concentration at the soil-chamber interface changes rapidly. For large h the flux density at the interface changes rapidly, and the concentration is relatively constant.

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