| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 621064 | Chemical Engineering Research and Design | 2016 | 15 Pages |
•Semi-IPN superabsorbent chitosan-starch hydrogel has been synthesized via chemical crosslinking.•Swelling kinetic investigations were performed to examine the water retention capacity.•Batch sorption studies were carried out to evaluate the performance of the hydrogel.•Isotherm, kinetics and thermodynamic study was applied to best describe the sorption process.•Sorption–desorption analyses were performed to demonstrate the reusability of the hydrogel.
This article reports the efficient removal of Direct Red 80 (DR80) dye from aqueous phase using a semi-interpenetrating network (IPN) superabsorbent chitosan-starch (ChS) hydrogel. In the present investigation, the influence of initial pH, ChS dose, initial dye concentration, temperature and effect of salts on the sorption of DR80 dye was evaluated. A maximum swelling capacity of 15 g/g was determined for ChS hydrogel. The sorption equilibrium data demonstrated good agreement with Freundlich isotherm. The sorption process best fitted the pseudo-second order kinetic model. Maximum uptake capacity of the hydrogel was determined as 312.77 mg/g. The mean sorption energy (E = 11.34–14.9 kJ/mol) demonstrated that DR80 sorption was mainly chemisorption. The temperature dependence data revealed the sorption process was spontaneous, endothermic and favourable at higher temperature based on the enthalpy (ΔH° = +83.68 kJ/mol) value obtained. Boyd model confirmed intraparticle diffusion was the limiting step for DR80 uptake. In addition, sorption/desorption studies were performed to investigate the reusability of ChS hydrogel which demonstrated significant sorption for four consecutive cycles.
Graphical abstractFigure optionsDownload full-size imageDownload high-quality image (194 K)Download as PowerPoint slide
