Eco-friendly valorization of agricultural sawdust waste for efficient elimination of dye and antibiotic contaminants from aquatic environments

Abstract Valorization of lignocellulosic waste into functional carbonaceous materials offers a sustainable approach for removing emerging organic contaminants from water. In this study, sawdust was directly carbonized at 300, 500, and 700 °C and functionalized with ferrocene (0.05–250 wt%) to produce composites for the removal of amoxicillin and Brilliant Blue R-250 under visible/simulated solar irradiation. The materials were characterized by FTIR, XRD, SEM, UV–visible spectroscopy, optical band-gap analysis, and N 2 adsorption–desorption. Among the prepared composites, S 6 (25 wt% ferrocene) exhibited the highest apparent photocatalytic activity toward Brilliant Blue, whereas S 4 achieved approximately 75–80% removal within 120 min. The degradation kinetics followed the pseudo-first-order Langmuir–Hinshelwood model (R 2 > 0.98), indicating surface-mediated photochemical processes. Overall, Ferrocene@AC500 (1:1) and AC300 exhibited the best removal/degradation performance toward the investigated pollutants.