Cross-linked chitosan-adipic/zirconia (ZrO2) nanocomposite for removal of eosin y dye: insight into physicochemical properties, adsorption modelling, isotherms, and kinetics

A nanocomposite adsorbent of cross-linked chitosan-adipic/zirconia nanoparticles (CHI-ADI/ZNPs) was successfully formed through the modifying of a naturally occurring polymer (CHI) with a nanoscale material (zirconia, ZrO2), which was subsequently subjected to an ionic cross-linking technique facilitated by adipic (ADI). The physicochemical properties of this innovative nanocomposite have been thoroughly investigated utilising a variety of techniques, such as CHN, XRD, FTIR, FESEM-EDX, and BET. Using response surface methodology, the capacity of CHI-ADI/ZNPs to remove organic dye (Eosin Y, EY) from an aqueous system was thoroughly investigated, with adsorption-influencing parameters including CHI-ADI/ZNPs dosage (0.02-0.08 g), removal time (10-90 min), and pH solution (4-10). Using the Langmuir and Temkin isotherm, the equilibrium behaviour of EY as determined by CHI-ADI/ZNPs is well illustrated. The adsorption kinetics data of EY by CHI-ADI/ZNPs were aptly characterised by a model of the pseudo-first-order. At 199.84 mg/g, CHI-ADI/ZNPs exhibit a remarkably adsorption capacity. The efficient adsorption of EY onto the CHI-ADI/ZNPs is likely assigned to H-bond interactions, n-pi stacking, and the positively charged CHI-ADI/ZNPs and EY anions. The findings of this research illustrate the exceptional adsorption capabilities of CHI-ADI/ZNPs in the context of eliminating synthetic anionic dyes from wastewater.