Preparation of magnetic chitosan- graphene oxide-MnFe2O4 nanocomposite and its application for removal of naphthol blue black (NBB)

In this study, a novel chitosan, graphene oxide and MnFe2O4 composite (CS-GO-MnFe2O4) was prepared as a magnetic bioadsorbent for water purification. The morphology, chemical structure and magnetic property of the composite were characterized by FT-IR, XRD, SEM and VSM analysis. The resulting composite shows good adsorption capacity for removal of naphthol blue black (NBB) as an acid dye model, in water. Adsorption of NBB onto CS-GO-MnFe2O4 was investigated with respect to pH, adsorption time, initial NBB concentration and temperature. The study of the adsorption isotherms and kinetics at the optimum pH 6.0, revealed that the pseudo-second-order kinetic and Langmuir isotherm model well-described kinetics and equilibrium adsorptions, respectively. The values of thermodynamic parameters (ΔG, ΔH and ΔS) indicated that the adsorption process is spontaneous and exothermic in nature. The results show that, more than 80% color removal could be achieved in 60 min contact time with 40 mg L−1 of initial concentrations.