Adsorption of methyl-orange from aqueous solution onto nanoporous silica materials

The batch-adsorption experiments are carried out for anionic dye(methyl orange) using uncalcined mesoporous materials, calcined mesoporous materials and modified mesoporous materials by impregnation method using polyelectrolyte (PDDA, poly (diallydimethylammonium chloride)) as a modification agent. The resulting samples were characterized by XRD, FT-IR and nitrogen adsorption–desorption analysis. The results indicate that uncalcined MCM-48 silica mesoporous molecular sieves (noted as MCM-48) can be used as the effective adsorbent for the removal of methyl orange (MO) from aqueous system. The effect of various factors such as chemical modification, contact time, initial concentration, adsorbent dose, agitation speed, and solution pH and reaction temperature has been studied. The experimental data obtained with MCM-48 fits best to the Langmuir isotherm model and exhibits a maximum adsorption capacity (qmax) of 769.23 mg g−1; and follows the second-order equation.