A coupled reactive chemical transport model:: mixing cell model with two solid phases and its application

A research tool for modeling the reactive flow and transport of groundwater contaminants in a one-dimensional scheme is presented. The use of a mixing cell concept with two solid phases for hydrological transport, and the incorporation of chemical reactions, recoil processes and phase transformation of minerals are some features of the model that make it a versatile research tool for the modeling of a wide variety of laboratory and field experiments. The treatment of chemical reactions is general so that the model can deal with aqueous complexation, adsorption, ion exchange, precipitation reaction, and decay reaction. The model has been applied to the analysis of uranium data obtained from the weathered zone of Koongarra uranium ore deposit in Australia, which illustrates some of these features.