Aminated magnetic polymeric resin for removal of anthraquinone and azo dyes from aqueous solutions

In this study, aminated magnetic polymeric resin (AMPR) was synthesized by low cost, facile, feasible method, and was characterized with FTIR, XRD, FE-SEM, EDX, BET and TG-DTA techniques in detail. Afterwards, the usability of the AMPR as an adsorbent for removing of azo dye (Tartrazine, Tart.) and anthraquinone dye (Reactive Blue-4, RB-4) from aqueous solutions was investigated. For this purpose, the effects of adsorbent amount, pH, initial dye concentration, time and temperature on adsorption were examined. Isotherm and kinetic evaluations were made, and also the nature of adsorption of both dyes on the AMPR was determined by calculating thermodynamic parameters. In addition, the effect of ionic strength on the amount of adsorbed dyes was investigated by performing adsorption studies in a dense matrix medium. From the characterization studies, it was determined that AMPR has basic character and high thermal stability; its surface properties were also suitable for adsorption. It was observed that the maximum adsorption of both dyes on the AMPR occurred at acidic medium, also was determined that the adsorption of the tartrazine occurs in a monolayer, that of the RB-4 in a multilayer. Its adsorption capacity was calculated as 281 mg/g for Tartrazine, 297 mg/g for RB-4, respectively. It was determined that the adsorption kinetics of both dyes was more suitable for the pseudo-second order kinetic model, the electrostatic interaction was dominant in the adsorption, and it was spontaneous. Moreover, it was observed that AMPR did not lose its high removal affinity for both dyes both in the dense matrix medium and in the adsorption-desorption cycle repeated four times.