Anion exclusion during transport of chloride through soil columns

Several miscible displacement experiments have shown anions appearing earli er in effluent solution due to repulsion by negatively charged particle sur faces. In this article, we shall discuss the results obtained from the disp lacement of chloride through soil columns. The anion exclusion phenomenon i s modeled using one region convective dispersion equation and the two regio n anion exclusion model of van Genuchten (1981) which is conceptually simil ar to Krupp ei al. (1972). Both the models were successful in describing th e transport processes. The reduction in anion exclusion volume was observed when pore water velocity was increased and the breakthrough curves shifted towards one pore volume.