Iron-modified sugarcane bagasse and coffee grounds biochar for deferiprone removal from pharmaceutical wastewater

This study investigates iron-modified biochars derived from sugarcane bagasse (FeSBB) and spent coffee grounds (FeCGB) as adsorbents for the removal of deferiprone (DFP), a drug widely used in Thailand, from aqueous solutions and real pharmaceutical wastewater. An optimal Fe/biochar mass ratio of 0.5:1 was employed. Physicochemical characterization confirmed successful iron incorporation, resulting in enhanced surface functionality. Under optimized batch conditions, pH 7-9, 1 h contact time, 50 mg of biochar, 10 mL of 5 mg/L DFP, both FeSBB and FeCGB achieved near-complete DFP removal (~100%). Adsorption kinetics followed a pseudo-second-order model, while isotherm data were best described by the Freundlich model. Application to real pharmaceutical effluents demonstrated high adsorption capacities of 220 ± 2 mg/g for FeSBB and 203 ± 1 mg/g for FeCGB. This work represents the first report on DFP adsorption using biochar-based adsorbents and highlights the potential of iron-modified agro-industrial wastes for pharmaceutical wastewater treatment.