Methylene Blue Adsorption by Magnesium Oxide Nanoparticles Immobilized with Chitosan (CS-MgONP): Response Surface Methodology, Isotherm, Kinetics and Thermodynamic Studies

Document Type: Research Article

Authors

1 Chemical Engineering Department Erode Sengunthar Engineering College Erode

2 Vellore Institute of Technology

3 Chemical Engineering Department, AU College of Engineering

Abstract

In this research, a chitosan-immobilized magnesium oxide nanoparticle (CS-MgONP) was synthesized to evaluate it as a prospective adsorbent for a cationic methylene blue (MB) dye. For the synthesized adsorbent, functional groups were analyzed through Fourier transform infrared spectroscopy (FTIR). X-ray diffraction (XRD) and Scanning electron microscopy (SEM) were used to identify the structural and morphological observations. The evaluation of process parameters such as pH (5-9), CS-MgONP dosage (0.2-0.6g/L), initial MB concentration (10-30mg/L), and temperature (283-323K) on MB adsorption was done at equilibrium agitation time of 70 min using central composite design (CCD) of response surface methodology (RSM). MB removal percentage of 94.51% (desirability=0.829) was obtained under the optimal conditions of pH=7.28, dosage=0.47g/L, initial MB concentration= 19.37mg/L and temperature =309.76K. The adsorption onto CS-MgONP fits well with pseudo-second-order kinetics equation and equilibrium data made the best fit with Langmuir isotherm with maximum MB uptake capacity of 163.87mg/g.

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