Enhancement of adsorption and photocatalytic activity of MgO nanoparticles for the treatment of textile dye using ultrasound assisted process by Response Surface Methodology

The industrial processes with the greatest negative impact on the environment are caused by textile industries due to discharge of large volumes of colored wastewater contaminated with dyes and other chemical additives. These pollutants cause damages to the ecosystems. In this study, magnesium oxide nanoparticles (MgO NPs) were used for the removal of pollutants emerging from textile industries. The MgO NPs were synthesized by an eco-friendly approach using stabilizer, Saccharum officinarum. The MgO nanoparticles underwent characterization through UV-Vis spectroscopy, XRD, FTIR, and SEM. The surface neutrality of them was determined by PH at point of zero charge PH(pzc). Furthermore, MgO NPs have been used to remove pollutants from textile waste water by photocatalytic degradation and adsorption process simultaneously. A statistical approach employing the Response Surface Method (RSM) and Central Composite Design (CCD) was utilized to develop an experimental model for the efficient removal of pollutant through the adsorption process. The adsorption isotherm models, namely Freundlich and Langmuir, were applied to determine feasibility of adsorption process. A pseudo second order kinetic model was used to determine adsorption kinetics of dye removal by MgO NPs. The adsorption isotherms were used for the adsorption equilibrium studies. According to thermodynamic studies, adsorption of dye on MgO NPs is an exothermic spontaneous process. The experimental findings indicated the higher favorability of the photodegradation process over the adsorption method for the removal of Basic violet 1 (BV1) dye. The MgO nanoparticles show favourable efficacy at optimal values of pH about 7.5, BV1 dye concentration was 20 mg/L, amount of nanoparticles was0.01 g, ultrasonication time was 8 min and photo irradiation time was 240 min. The removal was observed to be 90.00% by adsorption process and 99.05% via photocatalytic method for the removal of BV1 dye.