Facile synthesis of polypyrrole decorated chitosan-based magsorbent: Characterizations, performance, and applications in removing cationic and anionic dyes from aqueous medium.

The adsorption characteristic of polypyrrole decorated chitosan-based magsorbent (MChs/Ppy) for the elimination of cationic crystal violet and anionic methyl orange dye from wastewater were explored. The characteristics of MChs/Ppy were studied by TGA, SEM/EDAX, TEM, BET, FTIR, VSM, and XRD analyses. The performance of MChs/Ppy towards the adsorption of CV and MO was investigated by the batch method. Removal performance was obtained to be 88.11 and 92.89% for CV and MO at the optimum conditions. The adsorption of CV was well described by pseudo 2nd order, while that of MO was best followed by the pseudo 1st order kinetics. The adsorption equilibrium data for both the dyes were fitted well with Langmuir adsorption isotherm with the maximum monolayer sorption capacity of 62.89 and 89.29 mg/g for CV and MO, respectively. The negative values of ΔH and ΔF accompanying with the removal of both dyes specified the adsorption process to be exothermic and spontaneous. Regeneration study showed that MChs/Ppy could be reused efficaciously up to three consecutive ad-/de-sorption cycles. The combined benefits of facile synthesis, non-toxicity, and good adsorption potential towards cationic and anionic dyes along with easy magnetic separability make MChs/Ppy as a novel adsorbent.