Raw Eggshell as an Adsorbent for Copper Ions Biosorption—Equilibrium, Kinetic, Thermodynamic and Process Optimization Studies
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Date
2023
Authors
Marković, Miljan
Gorgievski, Milan
Štrbac, Nada
Grekulović, Vesna
Božinović, Kristina
Zdravković, Milica
Vuković, Milovan
Journal Title
Journal ISSN
Volume Title
Publisher
MDPI, Switzerland
Source
Metals
Volume
13
Issue
2
Abstract
The study on the biosorption of copper ions using raw eggshells as an adsorbent is presented in this paper. The influence of different process parameters, such as: initial pH value of the solution, initial Cu2+ ions concentration, initial mass of the adsorbent, and stirring rate, on the biosorption capacity was evaluated. The SEM-EDS analysis was performed before and after the biosorption process. SEM micrographs indicate a change in the morphology of the sample after the biosorption process. The obtained EDS spectra indicated that K, Ca, and Mg were possibly exchanged with Cu2+ ions during the biosorption process. The equilibrium analysis showed that the Langmuir isotherm model best describes the experimental data. Four kinetic models were used to analyze the experimental data, and the results revealed that the pseudo-first order kinetic model is the best fit for the analyzed data. Calculated thermodynamic data indicated that the biosorption process is spontaneous, and that copper ions are possibly bound to the surface of the eggshells by chemisorption. The biosorption process was optimized using Response Surface Methodology (RSM) based on the Box-Behnken Design (BBD), with the selected factors: adsorbent mass, initial metal ion concentration, and contact time.
Description
Keywords
biosorption, response surface methodology, Box-Behnken design, eggshell, equilibrium, kinetics, thermodynamics, copper ions
Citation
DOI
10.3390/met13020206
Scopus
ISSN
2075-4701
ISBN
License
CC-BY