Study of methyl orange adsorption properties on ZnO-Al sub(2)O sub(3) nanocomposite adsorbent particles

The adsorption of methyl orange (MO) from an aqueous solution on the synthesized ZnO-Al sub(2)O sub(3) nanocomposite was investigated. The ZnO-Al sub(2)O sub(3) nanocomposite particles were composed of ZnO nanoflakes grown on the alumina particles (Al sub(2)O sub(3) core and ZnO shell). Under optimal conditions (MO concentration of 150 ppm, adsorbent concentration of 500 ppm, and the pH value of 4.5), the prepared nanocomposite showed adsorption capacity of 291 mg/g and the percentage removal of 97% at the equilibrium time of 30 min. It was found that the MO adsorption process was mainly controlled by intraparticle diffusion and film diffusion mechanisms which occurred simultaneously during the adsorption. The adsorption isotherm was well described by Langmuir isotherm model, which exhibited the maximum adsorption capacity of 344.83 mg/g. The obtained low-cost nanocomposite was proved to be a promising adsorbent for the removal of anionic dyes in industrial wastewater treatment.