Application of response surface methodology for optimization of fluoride adsorption from aqueous solution using MgO-based nanocomposites

Document Type: Original Research Paper

Authors

1 Department of physics, university of zabol, zabol, iran

2 1Department of Environmental Health, Zabol University of Medical Sciences, Zabol, Iran

3 2Department of Environmental Health, Zahedan University of Medical Sciences, Zahedan, Iran

4 4MSc of Environmental Health, Kerman University of Medical Sciences, Kerman, Iran

5 Department of Environmental Health, Zabol University of Medical Sciences, Zabol, Iran

6 Department of Chemistry, University of Dhaka, Dhaka 1000, Bangladesh

10.22034/jna.2020.1874451.1149

Abstract

Fluoride at high concentrations in water is detrimental to human health. To find an efficient means of removal of fluoride from aqueous system, we synthesized magnesium oxide (MgO)- based iron-cobalt-manganese (MgO-FCN ) nanocomposites via co-precipitation. Fluoride adsorption process was optimized by standard software. The effect of independent parameters such as pH (3-11), initial dose of nanoparticle (0.02-0.1 g/L), initial concentration of fluoride (10-50 mg/L) and reaction time (30-180 min) were optimized to obtain the best responses of fluoride removal using statistical Central Composite Design (CCD) in the procedure of response surface modeling. The best conditions were optimized as pH=5, initial concentration of nanoparticle =0.05 g/L, initial concentration of fluoride =50 mg/L and the process time of 90 min. Under these conditions, the removal efficiency of the fluoride by MgO-based nanocomposites was achieved as 84.64%. High correlation coefficients for the proposed model was also obtained (adjusted R2=0.9993 and R2=0.9984). The equilibrium data were analyzed using Langmuir, Freundlich, Temkin and Dubinin-Radushkevich isotherm models. The Langmuir model was found to be describing the data best. Kinetic studies showed that the adsorption followed a pseudo-second order reaction.

Keywords