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

Sustainable activated carbons were produced from Rosa brunonii Lindl. seeds through physical activation (PAC) and chemical activation (CAC) routes and evaluated for the removal of representative textile dyes, Disperse Orange 1 (DO1) and Eriochrome Black T (EBT), from water. The activation process induced pronounced structural and chemical transformations, leading to porous carbon frameworks with enriched carbon content of approximately 93 wt% and excellent thermal stability. Adsorption experiments demonstrated that dye uptake is strongly influenced by initial dye concentration, solution pH, temperature, and adsorbent dosage, and particle size. The chemically activated carbon exhibited superior adsorption performance, particularly toward EBT, achieving a maximum capacity of 256.4 mg g⁻¹, whereas the PAC reached 192.3 mg g⁻¹. For DO1, adsorption capacities of 73.0 and 69.4 mg g⁻¹ were obtained for PAC and CAC, respectively. Equilibrium adsorption behavior was best described by the Langmuir model, indicating predominantly monolayer adsorption, and the adsorption kinetics followed a pseudo-second-order model, suggesting strong dye–surface interactions. Adsorption was favoured at lower temperatures, consistent with an exothermic process. Solution pH had a pronounced effect on EBT adsorption, with maximum uptake under acidic conditions due to electrostatic attraction, whereas DO1 adsorption was largely pH independent. Overall, this study demonstrates the effective valorisation of agricultural waste into high-performance adsorbents and highlights Rosa brunonii seed-derived activated carbons as promising materials for sustainable textile wastewater remediation.