Transportation of copper (II) ions from aqueous solutions to a fly ash and bentonite complex amorphous heterogeneous oxides (AHO: CaO-SiO2-Al2O3-MgO-FeO) system was studied. The particles of the fly ash and bentonite complex AHO system were highly porous and composed of platelike grains. They provide the physical basis for establishing a liquid-solid reaction model applicable to mesoporous solids. The main innovation of this model was in simplifying the powder granules to aggregates of close particles, while the particles act in accordance with the model better. The calculated curves from the models were well in line with the experimental results. (c) 2007 Elsevier Inc. All rights reserved.