Kinetics and isotherms of adsorption of fluoride onto Fe3O4/graphene/alginate nanocomposite hydrogel

Abstract

Fluoride (F-) is that the foremost toxicant affecting almost 200 million people worldwide. Present work involves defluoridation experiments utilizing magnetic iron oxide nanoparticles (Fe3O4NPs) fabricated on the graphene/alginate nanocomposite hydrogel. The Fe3O4NPs was synthesized via waste flowers (rose) obtained from temples via green route and chemically graphene oxide (GO) was prepared through lead of pencil. Batch trials were conducted to analyze the relation of F- ions with different parameters such as pH, contact period, fluoride concentration and dose. The surface structure of nanoparticles (NPs), functional groups contribution and elements availability in the hydrogel was examined through field emission scanning electron microscope (FESEM), x-ray diffraction (XRD), energy dispersive x-ray analysis (EDX), fourier transform infrared spectroscopy (FTIR) techniques. The developed hybrid Fe3O4/graphene/alginate nanocomposite hydrogel exhibits a maximum defluoridation capacity of 7.51 mg g−1. Maximum removal percentage was attained for 2 and 10 mg L-1F- content as 85.5% to 59% at pH 5 and 120 min. The equilibrium isotherm study was fitted with Freundlich isotherm model. Pseudo-second-order kinetic model (R2 = 0.988) was favoured divulged that the insight of F- ions took place through chemisorption processes on GO/Fe/Alginate nanocomposite hydrogel.