Work

Valorization of grape seed residues post-oil extraction as an adsorbent for hexavalent chromium in water. Kinetics, isotherms, thermodynamics, and techno-economic analysis

Year: 2025

Type: article

Abstract: • The maximum adsorption capacity of GSR-POE for Cr (VI) is 169.48 mg/g. • The adsorption mechanisms involved in the process are chemisorption and electrostatic attraction. • The adsorption process is endothermic and spontaneous. • The techno-economic analysis confirms that the process is economically viable and profitable. The objective of the present research was to valorize grape seed residues post-oil extraction (GSR-POE) obtained by pressing as a potential adsorbent of Cr (VI) from simulated aqueous solutions. For this, we first compared the removal of Cr (VI) by grape seeds (GS) and GSR-POE, obtaining that GSR-POE achieves higher removal efficiency than GS. Subsequently, it was determined that, with a particle size of 75 μm of GSR-POE and pH=2, the adsorption efficiency of Cr (VI) was favored, achieving the removal of 68.76 % of a simulated aqueous solution of Cr (VI) of 100 mg/L with a GSR-POE dosage of 0.8 g/L. The kinetic study showed that the GSR-POE adsorption process best fitted the pseudo-second order model, likewise, the Langmuir isotherm best described the process resulting in a maximum adsorption capacity of 169.48 mg/g. The thermodynamic study showed that the process is endothermic and spontaneous. The mechanisms involved in the adsorption process would be chemisorption and electrostatic attraction as there is a higher adsorption at pH=2 which is lower than the point of zero charge of GSR-POE (pH PZC = 4.95). Finally, a techno-economic analysis confirmed the economic viability and profitability of implementing a plant for GSR-POE production. In conclusion, under the conditions of this study, GSR-POE is a cost-effective and efficient adsorbent for Cr (VI) adsorption.

Source: Energy Nexus

DOI: 10.1016/j.nexus.2025.100437

Authors: Elvis G. Gonzales-Condori, Dalescka G. Bejar-Aramburu, Joan A. Gutierrez-Delgado, José A. Villanueva-Salas, Jonathan Gonzales-Condori, Betty M. Salazar-Pinto

Institution: Catholic University of Santa María

Language: English

Topic: Adsorption and biosorption for pollutant removal

Subfield: Water Science and Technology

Field: Environmental Science

Domain: Physical Sciences

SDGs: Responsible consumption and production, Clean water and sanitation

Open Access status: gold

Estimated APC paid: $2,200