Synthesis of modified maghemite nanoparticles and its application for removal of Acridine Orange from aqueous solutions by using Box-Behnken design

In this study, sodium dodecyl sulfate-coated maghemite nanoparticles (SDS-coated gamma-Fe2O3 NPs), was used for removal of cationic dye Acridine Orange from water samples. The gamma-Fe2O3 NPs were synthesized by co-precipitation method and were characterized by scanning electron microscope (SEM) and vibrating sample magnetometer (VSM) to examine their size and magnetic moment. The adsorption experiments were performed using the batch system. The prepared magnetic adsorbent was well dispersed in water and easily separated magnetically from the medium after loaded with adsorbate. Four most important operating variables including initial pH of the solution, dosage of adsorbent, concentration of dye and contact time was studied and optimized by response surface methodology (RSM), involving Box-Behnken design matrix. Twenty-seven experiments were performed to investigate the effect of these parameters on removal of the dye. The results showed that initial pH of the solution was the most effective parameter in comparison with others. Also, experimental parameters were optimized and chose the best conditions by determination of effective factors. The optimized conditions for dye removal were at initial pH 5.1 0.8 g L-1 of adsorbent, 30.0 mg L-1 dye and 43 min adsorption time The experimental data were analyzed by the Langmuir and Freundlich adsorption models. The maximum predicted adsorption capacities for Acridine Orange was 285.82 mg g(-1). (C) 2015 Elsevier B.V. All rights reserved.