One-dimensional solute transport in stratified sands at short travel distances

This paper presents laboratory-scale experimental observations on the migration of a non-reactive pollutant, sodium chloride, through stratified sands at short travel distances under one-dimensional flow conditions. Sand stratifications, perpendicular, parallel and inclined to the main flow direction, were used and contrary to most other published research work, flow was forced through the stratifications at a constant mean pore water velocity. The paper therefore examines the isolated effects of the different dispersion properties and particle size distribution of the sands used on their dispersion behaviour in different stratification configurations under the specified flow conditions. The initial part of the work on homogeneous sands produced differences in the dispersion which was found to be particle size distribution- and volume-dependent. For the stratified configurations and for the same volume of soil, the results showed different dispersion behaviour at the outflow position depending on the type of stratification and the sequence of the sands within each stratification. The paper presented a picture of the effect of various soils and flow conditions imposed on the transport of the solute and provided useful data on the profile of solute concentration for remediation purposes.