Miscible Displacement: II. Behavior of Tracers

Abstract It is of interest to know the microscopic flow velocity distribution of water moving through soil. Dissolved constituents frequently have been used to trace water movement in porous materials. It is apparent from this and previous investigations, that the distribution of a tracer some distance from its source, depends upon the geometry of the porous material and the physical and chemical interaction of the tracer solution and media during flow. Therefore, investigators studying water movement using tracers are compelled to ascertain the importance of the interaction of tracer solution in the media. Tritium and chloride ion were used as tracers for water flowing under stationary conditions in laboratory soil columns. The distribution of the tracers measured in the effluent is explained on the basis of the relative effects of pore geometry, diffusion rates, adsorption and exchange.