Oak wood ash/GO/Fe3O4 adsorption efficiencies for cadmium and lead removal from aqueous solution: Kinetics, equilibrium and thermodynamic evaluation

Rasool Pelalak,Zahra Heidari,Seyed Mola Khatami,Tonni Agustiono Kurniawan,Azam Marjani,Saeed Shirazian

doi:10.1016/j.arabjc.2021.102991

Abstract

Magnetic Oak wood ash/Graphene oxide (Ash/GO/Fe3O4) nanocomposites were designed as a high potentadsorbentin the removal of toxic heavy metals such as Lead (Pb(II)) and Cadmium (Cd(II)) ions from aquatic medium. Characterization of Ash/GO/Fe3O4 samples was carried out using FESEM, TEM, EDX mapping, BET/BJH, XRD, FTIR, and VSM methods. The obtained results confirmed the successful synthesis of Ash/GO/Fe3O4 nanocomposites. In the adsorption process, almost complete adsorption efficiency of produced Ash/GO/Fe3O4 nanocomposite was attained under the optimized conditions (99.67% and 98.68% for Pb(II) and Cd(II) adsorption, respectively). The modeling results of kinetics indicated that the mechanism of Pb(II) and Cd(II) adsorption process well fitted by pseudo-second order equation with a high regression coefficient (99.67%). In addition, the equilibrium data were described well by non-linear Langmuir model with the highest adsorption capacity of 47.16 mg/g and 43.66 mg/g for Pb(II) and Cd(II) ions, respectively, which prove the effective adsorption ability of the magnetic nanocomposite. The spontaneous and exothermic nature of adsorption process was confirmed through thermodynamics analyses. The reusability of synthesized Ash/GO/Fe3O4 nanocomposites were demonstrated with negligible decrease in adsorption and high stability up to 8 repetitive adsorption cycles. The mechanism of Pb(II) and Cd(II) adsorption on the Ash/GO/Fe3O4 nanocomposite was assessed.

Highlights

In recent years, the increment of population and development of human activities by different industries and manufacturing processes resulted in increase in type and amount of the released hazardous materials to the aquatic environment (Alkherraz et al, 2020; Heidari et al, 2021)
The broad adsorption peaks around 3379, 3421 and 3400 cmÀ1 were observed for graphene oxide (GO), ash and Ash/GO/Fe3O4 nanocomposite, which were related to OAH stretching vibrations of the H2O molecule (Farooq and Jalees, 2020; Pelalak and Heidari, 2014; Pelalak et al, 2020)
The adsorption bonds related to the GO and Ash was discovered in the FTIR spectrum of the Ash/GO/Fe3O4 composite, which indicated the successful synthesis of the magnetic nanocomposite

Summary

Introduction

The increment of population and development of human activities by different industries and manufacturing processes resulted in increase in type and amount of the released hazardous materials to the aquatic environment (Alkherraz et al, 2020; Heidari et al, 2021) Among these pollutants, the heavy metals, including cadmium (Cd), arsenic (As), lead (Pb), mercury (Hg), and thallium (Tl) are the most serious hazardous materials which are being produced by electroplating, metallurgy, leather tanning and pesticides industries (Heidari et al, 2020; Liu et al, 2020; Pelalak et al, 2020; Zhao et al, 2018). Fe3O4 nanoparticles according to their high adsorption capacity and surface area have been employed in many treatment processes Utilization of these nontoxic nanoparticles as active phase on GO could be very effective and economical (Wang, 2018)

Methods

Results

Conclusion