Fabrication of mixed phase CaFe2O4 and MnFe2O4 magnetic nanocomposite for enhanced and rapid adsorption of methyl orange dye: statistical modeling by neural network and response surface methodology

Abstract

In this study, a new magnetic material, mixed phase of CaFe2O4 and MnFe2O4 magnetic nanocomposite (CaF-MnF-MNC) was successfully synthesized by a facile co-precipitation method. The CaF-MnF-MNC was used as an adsorbent to explore its potential for remediation of methyl orange (MO) dye from aqua matrix. The X-ray diffraction (XRD) pattern of the prepared material confirms the formation of mixed phase of CaFe2O4 and MnFe2O4 spinel ferrites. Room temperature vibrating sample magnetometer (VSM) measurement reveals saturation magnetization of CaF-MnF-MNC as 38.17 emu/g, which could separate the adsorbent from dye solution efficiently. The batch mode adsorption experiments revealed that CaF-MnF-MNC has higher adsorptive potential for MO dye as compared to pure CaFe2O4 and MnFe2O4 nanoparticles. Response surface methodology (RSM) based optimization revealed the optimal experimental condition at CaF-MnF-MNC dose of 0.58 g/L, initial MO dye concentration of 98.37 mg/L and contact time of 24 min for maximum MO dye removal efficiency of 99.88%. Artificial neural network (ANN) modeling has shown better prediction ability for MO dye adsorption efficiency as compared to RSM model. The second order kinetic and Langmuir isotherm models were found to be best fitted with the experimental data and CaF-MnF-MNC exhibited maximum MO dye adsorption capacity of 344.83 mg/g.