ABSTRACT
This chapter deals with the mass balance equation for the transport of dissolved constituents. It emphasizes analytic solutions for one-dimensional problems, use the z-transform to simulate system response, and demonstrate how one solution can be obtained from another solution. Factors affecting solute transport are advection, dispersion, adsorption, and sources. Dispersion modifies the pattern of advective transport. It causes an initially sharply defined pulse of solute input to become fuzzy at its leading and trailing edges of a solute plume. Because of dispersion, solute transport lacks a well-defined migration front for the determination of transport velocity. The apparent velocity for the breakthrough varies with distances even for a one-dimensional, one-component solute transport model. Analytic solutions are obtained by convolving source functions with impulse response in time and space. Such solutions are usually in integral forms that require numerical integration.
