Application of novel magnetic β-cyclodextrin-anhydride polymer nano-adsorbent in cationic dye removal from aqueous solution

Novel series of p-cyclodextrin (beta CD) and beta CD-anhydride polymer coated magnetic nanoparticles (Fe@CDA2) were prepared and evaluated for Rhodamine B (RhB) and Methylene Blue (MB) adsorption. The adsorbents were characterized by FTIR, XRD, SEM, TGA, and VSM analysis. Batch adsorption experiments showed that the adsorption was quite fast, and the percentage of RhB and MB, removed in the first 10 min of the process, was 71 and 87% of the final equilibrium values, respectively, and adsorption followed a pseudo-second-order kinetic model. The adsorption was dependent on pH, dye initial concentration, and adsorbent dosage. Higher adsorption capacity was obtained at pH 12 for both dyes. The adsorbent dose of 2 and 1.5 g/L were chosen as the optimum values for RhB and MB, respectively. The equilibrium data were well represented by the Langmuir model and the maximum capacities (q(m)) of MB and RhB by Fe@CDA2 were found to be 333.3 and 250.0 mg/g, respectively. The adsorbed dye could be desorbed using methanol solution containing 5 vol% acetic acid which desorbed 99.5 and 98.0% of the adsorbed RhB and MB dye, respectively. The regenerated adsorbent was used again in adsorption process, and after five cycles of reuse, only 10% decrease was observed in adsorption capacity of Fe@CDA2. 2017 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.