Sustainable biomass-derived activated carbons from Rosa brunonii seeds for high-efficiency textile dye removal from water

Abstract

Sustainable activated carbons were prepared from Rosa brunonii Lindl. seeds via physical (PAC) and chemical (CAC) activation and evaluated for the adsorption of textile dyes Disperse Orange 1 (DO1) and Eriochrome Black T (EBT) from water. Both activation routes induced significant structural and chemical transformations, producing highly porous carbons with carbon contents of ~93 wt.% and excellent thermal stability. Adsorption performance was strongly influenced by initial dye concentration, pH, temperature, adsorbent dosage, and particle size. CAC exhibited superior adsorption efficiency, particularly for EBT, achieving a maximum capacity of 256.4 mg/g compared to 192.3 mg/g for PAC. For DO1, adsorption capacities of 73.0 and 69.4 mg/g were obtained for PAC and CAC, respectively. Equilibrium data were best fitted by the Langmuir isotherm, indicating monolayer adsorption, while adsorption kinetics followed a pseudo-second-order model, suggesting strong dye–surface interactions. Adsorption was favored at lower temperatures, consistent with an exothermic process. EBT adsorption showed strong pH dependence, with enhanced uptake under acidic conditions due to electrostatic attraction, whereas DO1 adsorption was largely pH independent. These results demonstrate the effective valorization of agricultural waste into high-performance adsorbents and highlight Rosa brunonii seed-derived activated carbons as promising materials for sustainable textile wastewater treatment.