Effective Removal of Azo Dye Reactive Blue 222 from Aqueous Solutions Using Modified Magnetic Nanoparticles with Sodium Alginate/Hydrogen Peroxide

The present work aimed to study the removal efficiency of Reactive Blue 222 (RB222) from aqueous solutions by applying a combined process with magnetic sodium alginate beads/H2O2. The effect of various operating parameters including sodium alginate dosage, H2O2 concentration, pH, and dye concentration on the efficiency of the process was investigated. The Freundlich and Langmuir isotherms were used to explain the adsorption process. Adsorption kinetics of RB222 with magnetic sodium alginate beads were also investigated using the pseudo‐first‐, second‐order, and intra‐particle diffusion kinetic models. Optimum conditions for dye removal were determined at [dye concentration] = 50 mg/L, [H2O2] = 250 mg/L, and [pH] = 3 with a reaction time of 180 min. Dye removal percentages obtained in this research were 54.51% and 90.39% using magnetic sodium alginate and magnetic sodium alginate/H2O2 processes, respectively. SEM and XRD were used for the characterization of the obtained magnetic sodium alginate beads. It was revealed that the adsorption of the dye in sodium alginate beads was more consistent with the Freundlich model (R2 = 0.9934) compared to that of the Langmuir model (R2 = 0.7457). Also, the results demonstrated that the adsorption of RB222 in magnetic alginate beads was consistent with the pseudo‐second‐order kinetic models (R2 = 0.9854).