Removal of metal complexed azo dyes from aqueous solution using tris(2-aminoethyl)amine ligand modified magnetic p(GMA-EGDMA) cationic resin: Adsorption, isotherm and kinetic studies

This study demonstrates efficient removal of Reactive Green 5 (RG-5) and Reactive Brown 10 (RB-10) metal complexed dyes from aqueous solution using tris(2-aminoethyl)amine ligand (TAA) attached magnetic poly(glycidylmetharylate-ethyleneglycol dimethacrylate), Mp(GMA-EGDMA)-TAA, resin. The chemical structure and morphology of the magnetic resin were characterized by FTIR, XRD, SEM, VSM, BET, and analytical methods It was observed that the synthesized resin has ferromagnetic behavior under magnetic field which can permit for effective separation from adsorption medium. In the remaining study, the adsorption of RG-5 and RB-10 dyes from their aqueous solutions was realized with Mp(GMA-EGDMA)-TAA resin by varying of initial pH, resin dosage, initial dye concentration, temperature and salt concentration. The maximum adsorption capacity of the resin was found to be 238.7, and 162.4 mg/g for RG-5 and RB-10 dyes, respectively. Kinetics and isotherm models, and adsorption thermodynamic were investigated to best describe the sorption process. The results accorded with the pseudo-second-order kinetic model. The Langmuir and Temkin isotherm models can describe the adsorption process appropriately. The thermodynamic parameters indicated that the sorption process was exothermic. In addition, adsorption/desorption studies were performed to evaluate the reusability of the Mp(GMA-EGDMA)-TAA resin, and more 94% of the adsorbed metal complexed dye can be desorbed from the magnetic resin. Repeated use test indicated that the synthesized magnetic resin had good reusability performance especially up to fifteen cycle. Finally, the Mp(GMA-EGDMA)-TAA resin proved to be a sustainable resin effective in low dosage and magnetically separable after laden with pollutant compounds. Thus, the synthesized resin could significantly reduce operation time, and could be applied for treatment of industrial effluents rich in inorganic and organic pollutants. (C) 2017 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.