Adsorption Isotherms and Thermodynamics for Chromium (VI) Using an Anion Exchange Resin

Abstract

In the present study, adsorption isotherms and thermodynamics were performed using aqueous solutions of chromium (VI) and an anion exchange resin which was have not yet been characterized for this ion. The adsorption results were fitted to Langmuir, Freundlich, Dubinin-Radushkevich, and Temkin-Pyzhev sorption models. The highest correlation factor (R²) was observed for the Freundlich isotherm which indicates sorption upon a heterogeneous surface. The thermodynamic parameters such as the Gibb’s free energy (ΔG°), the standard enthalpy (ΔH°), and the standard entropy (ΔS°) were determined, indicating that the chromium (VI) adsorption process was spontaneous and endothermic. This study contributes to a clearer understanding of the Cr (VI) adsorption onto the studied anion resin. Our target is to found materials suitable with the world’s growing interest in the treatment of wastewater.

Keywords:

• Adsorption
• anion exchange resin
• chromium (VI
• )
• thermodynamics
• water pollution

Disclosure statement

The authors declare that they have no conflicts of interest.

Additional information

Funding

This work was supported by the Romanian Ministry of Education and Research under the project 32PFE/19.10.2018.