Surface Modification of Spinel Ferrite with Biopolymer for Adsorption of Cationic and Anionic Dyes in Single and Ternary Dye System

Abstract

In this work, nano cobalt ferrite was modified with biopolymer sodium alginate in alginic form and the prepared magnetic composite (CoFN-Alg) was examined by different techniques such as Fourier transform infrared spectroscopy, transmission electron microscope with energy dispersive spectra, X-ray diffraction, thermo-gravimetric analysis, and Brunauer-Emmett-Teller equation. The CoFN-Alg composite was used as adsorbent to remove Congo red (CR), brilliant green (BG), and methylene blue (MB) dyes from single and ternary dye systems. The adsorption of different dyes on CoFN-Alg composite was studied at varying parameters such as contact time, varying pH, adsorbent dose, and initial concentration at different temperatures through batch mode. Results of kinetic studies revealed that the adsorption data of different dyes in single system as well as ternary system was best fitted in Lagergren pseudo second order model. Similarly, the adsorption equilibrium data was well correlated by Langmuir isotherm model in both types of dye systems. In single system, the maximum adsorption capacities of CR, BG, and MB dyes for CoFN-Alg composite were 93.0, 92.1, 95.8 mg/g and for ternary system were 60.0, 64.4, and 76.9 mg/g, respectively. The calculated adsorption thermodynamic parameters confirmed that adsorption process was spontaneous in nature. The results of regeneration studies concluded that CoFN-Alg composite retained around 78% regeneration efficiency even after five successive cycles in single as well as ternary system. The present study revealed that CoFN-Alg composite might be suitable alternative for the removal of different dyes in single as well as multi-component system.