Orbital - Vol. 11 No. 2 - Special Issue April 2019

Thermodynamics of Cr(VI) Adsorption on Magnetic Core-Shell Nanoparticles

Alex Fabiano Cortez Campos
Universidade de Brasília - UnB
Fabiana Narciso da Silva
Universidade de Brasília - UnB
Marcelo Rubens Braga de Almeida
Universidade de Brasília - UnB
Luana Cristina Alves Sales
Universidade de Brasília - UnB
Paulo Henrique Michels-Brito
Universidade de Brasília - UnB
Helena Augusta Lisboa de Oliveira
Universidade de Brasília - UnB
Published April 30, 2019
  • Cr(VI) adsorption,
  • magnetic nanoadsorbents,
  • thermodynamic parameters
How to Cite
Campos, A. F. C.; da Silva, F. N.; de Almeida, M. R. B.; Sales, L. C. A.; Michels-Brito, P. H.; de Oliveira, H. A. L. Thermodynamics of Cr(VI) Adsorption on Magnetic Core-Shell Nanoparticles. Orbital: Electron. J. Chem. 2019, 11, 64-70.


This work focuses on the influence of temperature on Cr(VI) adsorption by nanoadsorbents based on core-shell bimagnetic CoFe2O4@g-Fe2Onanoparticles. The nanoadsorbents were synthesized using the hydrothermal coprecipitation method in alkaline medium followed by a surface treatment with Fe(NO3)3. The effect of initial chromium concentration and temperature of adsorption were evaluated from batch studies using 0.7 g/L of the nanoadsorbents. The results were analyzed in the framework of the Langmuir and Freundlich models and showed that the nanoadsorbents removed more than 95% of Cr(VI) in pH = 2.5 for a contact time of 30 min. The thermodynamics of the adsorption process was investigated by means of calculation of the Gibbs free energy, enthalpy and entropy changes. The results revealed that the Cr(VI) adsorption process is spontaneous, endothermic and presents an increase in randomness at the solid-solution interface.

DOI: http://dx.doi.org/10.17807/orbital.v11i2.1331