Modeling of Reactive Blue 19 azo dye removal from colored textile wastewater using L-arginine-functionalized Fe3O4 nanoparticles: Optimization, reusability, kinetic and equilibrium studies

This study aimed to investigate the removal of Reactive Blue 19 from colored wastewater using Fe3O4 magnetic nanoparticles modified with L-arginine (Fe3O4@L-arginine). In order to investigate the effect of independent variables on dye removal and determining the optimum condition, the Box-Behnken Design (BBD) under Response Surface Methodology (RSM) was employed. Fe3O4@L-arginine nanoparticles were synthesized and characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, and vibrating sample magnetometer. Applying Fe3O4@L-arginine nanoparticles for dye removal showed that; by increasing adsorbent dose and decreasing pH, dye concentration, and ionic strength dye removal has been increased. In the optimum condition, Fe3O4@L-arginine nanoparticles were able to remove dye as high as 96.34% at an initial dye concentration of 50 mg/L, adsorbent dose of 0.74 g/L, and pH 3. The findings indicated that dye removal followed pseudo-second-order kinetic (R2=0.999) and Freundlich isotherm (R2=0.989). Based on the obtained results, as an efficient and reusable adsorbent, Fe3O4@L-arginine nanoparticles can be successfully applied for dye removal from colored wastewater.