ARS | Publication request: ANALYTICAL SOLUTIONS FOR THE TRANSPORT OF VOLATILE ORGANIC CHEMICALS IN UNSATURATED LAYERED SYSTEMS

Submitted to: Water Resources Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 10, 2000
Publication Date: August 10, 2000
Citation: Yates, S.R., Papiernik, S.K., Gao, F., Gan, J. 2000. Analytical solutions for the transport of volatile organic chemicals in unsaturated layered systems. Water Resources Research. 36:1993-2000.

Interpretive Summary: This paper develops and describes equations that can be used to predict the movement of a volatile organic chemical in a soil system comprising two separate layers. These solutions can be used to study the movement of agricultural fumigants from soils into a passive flux chamber, which is commonly used for measuring the surface volatilization rate. The equations are presented and the results are illustrated with several hypothetical examples. It was found that simplified assumptions concerning the movement from soil into a chamber can be adopted when virtually impermeable films are used to cover the soil surface.

Technical Abstract: Several analytical solutions describing the transport of volatile organic chemicals in layered porous media have been developed. Solutions are presented for a system consisting of either two finite soil layers or a finite layer adjacent to an infinite soil layer. The proposed solutions may provide useful tools for studying the movement of volatile chemicals (e.g., agricultural fumigants) in layered soils, as well as for the study of the movement from soils into passive flux chambers, which are commonly used for measuring the surface volatilization rate. The overall behavior of the solutions is illustrated by several examples showing the soil concentration and the flux density as a function of time.