Modeling and Optimization by RSM-BBD Design for Acid Dye Removal from Aqueous Solution using Water-Dispersible Superparamagnetic Iron Oxide Nanoparticles

This work presents the synthesis of Water-dispersible superparamagnetic iron oxide nanoparticles (SPIONS) Fe₃O₄ with different average sizes, obtained by different methods: co-precipitation with surface modification and polyol method. The obtained SPIONs, which were coated with (PEG /EG) with hydrophilic properties, showed excellent dispersion capacity in water and colloidal stability. The nanoparticles were analyzed by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The nanoparticles were used as adsorbents for the adsorption of Naphthol green B (NGB) dye in aqueous solutions, by optimizing adsorption parameters such as initial dye concentration, solution pH and adsorbent dose, using the Box- Behnken (BBD) response surface method. The results show that the BBD method is an effective approach to optimize the adsorption process and maximize the adsorption capacity of the dye. The Langmuir and Freundlich isotherm models were used to study the adsorption equilibrium, and the first- and second-order kinetic equations were used to model the adsorption kinetics.