Remediation of Astrazon blue and Lerui acid brilliant blue dyes from waste solutions using amphoteric superparamagnetic nanocomposite hydrogels based on chitosan prepared by gamma rays.

A nanocomposite hydrogel of chitosan/polypropenoic acid/ethylenediamine/magnetite (Cs/PPA/EDA/Fe3O4-NPs) was prepared using a gamma irradiation source (60Co). In the present study, chitosan/propenoic acid with different ratios and ethylenediamine were used as a matrix and Fe3O4 as a filler. The nanocomposite hydrogel was irradiated at 30 kGy using the γ-radiation technique as a crosslinking tool. The prepared nanocomposites were characterized utilizing several analytical techniques including Fourier transform infrared spectroscopy (FT-IR), vibrating sample magnetometer (VSM), and X-ray diffractometer (XRD). Results show that the Cs/PPA/EDA/Fe3O4-NPs nanocomposite has superabsorbent and superparamagnetic properties. The kinetic model of AB and LABB dyes adsorption onto the obtained nanocomposite hydrogel was confirmed and observed to be a pseudo-second-order reaction. The thermodynamic study proved that the adsorption process is endothermic in nature. The Langmuir plot best fitted the other isotherm models. The prepared Cs/PPA/EDA/Fe3O4-NPs nanocomposite hydrogel showed an excellent adsorption capacity for the removal of hazardous and toxic basic Astrazon blue (193.21 mg/g) and acidic Lerui Acid Brilliant Blue (51.9 mg/g) dyes from contaminated solutions. The results reveal that the Cs/PPA/EDA/Fe3O4-NPs nanocomposite hydrogel significantly removed the hazardous, toxic basic AB and acidic LABB dyes from waste solutions.