Removal of methyl orange from synthetic wastewater using nano-MgO and nano-MgO/UV combination

In this study, the potential of MgO nanoparticles in the adsorption of methyl orange (MO) as an azo dye and also the effectiveness of UV radiation in the performance improvement of MgO nanoparticles in terms of MO dye adsorption were assessed. The dye removal experiments were carried out in the batch reactors. MgO dosage in the range of 0.1-3.5g/L, mixing time of 0-120min, dye concentration of 100-800mg/L, and pH of 8-10 were applied. The results of this investigation showed that the optimum dose of azo dye, optimum dose of MgO nanoparticles, and optimum contact time for obtaining the best performance in dye adsorption were about 300mg/L, 1.5g/L, and 10min, respectively. UV light improved MgO efficiency in MO adsorption. In the presence compared to the absence of UV light, to obtain 90% adsorption efficiency of 100mg/L MO, only half the dose of MgO was needed. The isotherm studies showed that the Langmuir isotherm was the best adoption to express the adsorption behavior.