Mercury removal from aqueous solutions with chitosan-coated magnetite nanoparticles optimized using the box-behnken design

Nadereh Rahbar; Alireza Jahangiri; Shahin Boumi; Mohammad Javad Khodayar

doi:10.17795/jjnpp-15913

Mercury removal from aqueous solutions with chitosan-coated magnetite nanoparticles optimized using the box-behnken design

Jundishapur J Nat Pharm Prod. 2014 Apr 13;9(2):e15913. doi: 10.17795/jjnpp-15913. eCollection 2014 May.

Authors

Nadereh Rahbar¹, Alireza Jahangiri¹, Shahin Boumi², Mohammad Javad Khodayar³

Affiliations

¹ Nanotechnology Research Center, Jundishapur University of Medical Sciences, Ahvaz, IR Iran ; Department of Medicinal Chemistry, School of Pharmacy, Jundishapur University of Medical Sciences, Ahvaz, IR Iran.
² Department of Medicinal Chemistry, School of Pharmacy, Jundishapur University of Medical Sciences, Ahvaz, IR Iran.
³ Department of Pharmacology and Toxicology, Toxicology Research Center, School of Pharmacy, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, IR Iran.

Abstract

Background: Nowadays, removal of heavy metals from the environment is an important problem due to their toxicity.

Objectives: In this study, a modified method was used to synthesize chitosan-coated magnetite nanoparticles (CCMN) to be used as a low cost and nontoxic adsorbent. CCMN was then employed to remove Hg(2+) from water solutions.

Materials and methods: To remove the highest percentage of mercury ions, the Box-Behnken model of response surface methodology (RSM) was applied to simultaneously optimize all parameters affecting the adsorption process. Studied parameters of the process were pH (5-8), initial metal concentration (2-8 mg/L), and the amount of damped adsorbent (0.25-0.75 g). A second-order mathematical model was developed using regression analysis of experimental data obtained from 15 batch runs.

Results: The optimal conditions predicted by the model were pH = 5, initial concentration of mercury ions = 6.2 mg/L, and the amount of damped adsorbent = 0.67 g. Confirmatory testing was performed and the maximum percentage of Hg(2+) removed was found to be 99.91%. Kinetic studies of the adsorption process specified the efficiency of the pseudo second-order kinetic model. The adsorption isotherm was well-fitted to both the Langmuir and Freundlich models.

Conclusions: CCMN as an excellent adsorbent could remove the mercury ions from water solutions at low and moderate concentrations, which is the usual amount found in environment.

Keywords: Chitosan; Magnetite Nanoparticles; Mercury.