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Production of Activated Carbon from Grape Pomace ( Vitis labrusca ) by Chemical Activation with ZnCl 2 and Its Application in Phenol Adsorption

Year: 2026

Type: article

Abstract: High Resolution Image Download MS PowerPoint Slide This study investigated the production of activated carbon from Vitis labrusca grape pomace through chemical activation with ZnCl 2 and subsequent carbonization at varying temperatures and times using a fractional factorial design. The best performance for phenol adsorption was obtained at 800 °C for 120 min, achieving a maximum adsorption capacity of 54.04 mg g –1 . The activated carbon presented a high specific surface area (1017.58 m 2 g –1 ), meso- and micro-porous structure (type I and IVa isotherms with H4 hysteresis), oxygenated functional groups, and thermal stability. Adsorption kinetics were studied at different phenol concentrations (50–150 mg L –1 ), and the experimental data were fitted to pseudo-first-order, pseudo-second-order, and Elovich models. The results revealed that the pseudo-second-order model better described the kinetic data. Regarding the equilibrium studies, the maximum adsorption capacity was 180 mg g –1 . Isotherm modeling indicated that the Freundlich model was the most appropriate. Thermodynamic analysis indicated that the adsorption process is spontaneous and favorable, with Δ G ° values of −18.85, −20.03, and −21.53 kJ mol –1 at 25, 45, and 55 °C, respectively, Δ H ° of 6.2 kJ mol –1, and Δ S ° of 83.8 J mol –1 K –1 at 45 °C, demonstrating that higher temperatures enhance adsorption. Reuse tests showed that after five adsorption–desorption cycles, the adsorbent maintained its mechanical integrity and physical stability. These findings confirm that grape-pomace-derived activated carbon is a sustainable and effective material for phenol removal from aqueous solutions.

Source: ACS Omega

DOI: 10.1021/acsomega.5c08993