Title
Cellulose-rich apricot stone shells as a sustainable biosorbent for efficient Crystal Violet dye removal: kinetic and thermodynamic insights
Authors
NAZIHA LADJAL, SMAIL TERCHI, BAHRI DEGHFEL and ABDELHAMID GUELIL

Received July 12, 2025
Published Volume 59 Issue 9-10 October-December
Keywords wastewater treatment, apricot stone shells, agricultural waste valorization, Crystal Violet removal

Abstract
This study explores the potential of apricot stone shells (ASS) as a cost-effective and eco-friendly biosorbent for the removal of Crystal Violet (CV) dye from aqueous solutions. The ASS material was characterized using XRD, FTIR, TG DTA, and surface area analysis, revealing a composition rich in cellulose, hemicelluloses and lignin, with a high specific surface area of 159 m²/g. Adsorption experiments demonstrated optimal performance at pH≥ 7 and 40 °C, achieving equilibrium within 60 minutes. Kinetic studies indicated a pseudo-second-order mechanism, while the Temkin isotherm best described the adsorption behavior, suggesting chemisorption on heterogeneous sites. Thermodynamic analysis confirmed the endothermic nature of the process, with a Gibbs free energy change (ΔG°) indicating spontaneity at higher temperatures. Remarkably, ASS maintained over 88% adsorption efficiency after four regeneration cycles, highlighting its reusability. These findings position ASS as a promising, sustainable alternative for wastewater treatment, leveraging agricultural waste for effective dye removal.