Efficient removal of methyl orange using magnesium oxide nanoparticles loaded onto activated carbon

Abstract

ABSTRACT. In this work, an activated carbon composite made with magnesium oxide nanoparticles (MgONP-AC) was effectively utilized for methyl orange (MO) adsorption. The effect of pH (6-10), mass of MgONP-AC (0.1-0.3 g/L), initial MO concentration (10-30 mg/L), and temperature (283-323 K) on MO removal was investigated using a central rotatable composite experimental design based on the response surface technique (RSM) at an equilibrium agitation period of 60 min. The studies predicted the optimal MO removal of 98.99% at pH 7.68, MgONP-AC dosage of 0.24 g/L, and starting MO concentration of 15 mg/L, and temperature of 313 K. Furthermore, an artificial neural network (ANN) was utilized to simulate MO adsorption, and it properly predicted MO removal using mean squared error (MSE) and R² for the testing data. The ANN predicts a maximum removal of 99.63% with ANN with R² = 0.9926. The kinetic results suited the pseudo-second order kinetic equation, and the data from the equilibrium investigations corresponded well with the Langmuir isotherm (maximum uptake capacity q_max = 346 mg/g). Endothermic, spontaneous, and physical adsorption were discovered during the thermodynamic investigations.

KEY WORDS: Adsorption, Artificial neural network, Experimental design, isotherms, Kinetics, Methyl orange, MgONP-AC

Bull. Chem. Soc. Ethiop. 2022, 36(3), 531-544.                                                               

DOI: https://dx.doi.org/10.4314/bcse.v36i3.4