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

ABSTRACT
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.