An efficient magnetic nanoadsorbent based on functionalized graphene oxide with gellan gum hydrogel embedded with MnFe layered double hydroxide for adsorption of Indigo carmine from water

The primary objective of this investigation was to synthesize a novel antibacterial nanocomposite consisting of natural gellan gum (GG) hydrogel, MnFe LDH, GO, and Fe₃O₄ nanoparticle, which was developed to adsorb Indigo carmine (IC). The GG hydrogel/MnFe LDH/GO/Fe₃O₄ nanocomposite was characterized through different analytical, microscopic, and biological methods. The results of adsorption experiments reveal that 0.004 g of the nanocomposite can remove 98.38 % of IC from a solution with an initial concentration of 100 mg/L, within 1 h at room temperature and under acidic pH conditions. Moreover, the nanocomposite material effectively suppressed the in vitro growth of both E. coli and S. aureus strains, with inhibitory rates of 62.33 % and 53.82 %, respectively. The isotherm data obtained in this investigation were fitted by linear and non-linear forms of Langmuir, Freundlich, and Dubinin-Radushkevich (D-R) isotherms equations. The results of the adsorption kinetics study indicated that the pseudo-second-order model best described the experimental data. The findings of this study suggest that the synthesized nanocomposites hold great potential as effective adsorbents for removing IC and bacteria from aqueous solutions.