Adsorption experimental data were analyzed using Langmuir, Freundlich and Dubinin–Radushkevich isotherm models along with the evaluation of adsorption energy and standard free energy (_G0). The adsorption was observed to be pH dependent. The main mechanism of dye adsorption was found to be a spontaneous charge associated interaction, except for EB adsorption on chitin/SiO2 matrix, which showed to involve a lower energy physical adsorption interaction.