1991 Volume 35 Pages 641-646
A description is given of a solute transport model in groundwater which includes multicomponent physico-chemical processes. The processes of cation exchange and of solid dissolution-precipitation are incorporated in the numerical solution of the convective-dispersive equation, using the method of characteristics. It is demonstrated that the converged values of concentration obtained by including the physico-chemical reaction routines satisfiy the mass balance, mass action, and charge balance criteria.