Removal of Reactive Blue 4 Dye from Aqueous Solution with Magnetic Fe3O4@Nd/Alg Beads

Abstract In this study, magnetic iron oxide@neodymium/alginate (Fe 3 O 4 @Nd/Alg) beads were prepared by ionic crosslinking with neodymium (Nd) ions, then subjected to heat treatment, and for the first time, effective removal of Reactive Blue 4 (RB 4) dye from aqueous solution was achieved with these beads. For this purpose, ideal adsorption conditions that significantly affect the removal of this dye were determined. The ideal adsorption conditions were determined as pH:5, contact time (t):60 min, amount of magnetic Fe 3 O 4 @Nd/Alg bead (m):10 mg, initial RB 4 dye concentration (C 0 ):25 mg/L, temperature (T): 25 °C. Adsorption isotherm, kinetic and thermodynamic studies were carried out under the ideal adsorption conditions. The adsorption data was found to completely follow Langmuir model for RB 4 dye and the maximum adsorption capacity of RB 4 was found to be 263.16 mg/g. The adsorption kinetic data was found to be compatible with pseudo-second order and adsorption processes were explained by intraparticle diffusion. In adsorption thermodynamics studies, it has been determined that the nature of the adsorption reaction is spontaneous, endothermic and with increasing randomness. Furthermore, reuse studies of magnetic Fe 3 O 4 @Nd/Alg beads were carried out and it was determined that these beads could be used successfully up to 10 adsorption/desorption cycles.