Adsorption of uranium(VI) from aqueous solution by nonliving Sargassum fusiforme biomass

Sargassum fusiforme (hijiki) dry powder was used to adsorb U(VI) from simulated wastewater. Environmental factors like reaction time, pH, temperature, and initial U(VI) concentration were examined. Optimal removal occurred at pH 5.0. The process followed pseudo-second-order kinetics and Langmuir isotherm, indicating chemisorption with a maximum capacity of 155.28 mg/g. Thermodynamics analyses implied the adsorption was endothermic and spontaneous. FTIR and SEM-EDS studies suggested that U(VI) uptake primarily occurred via ion exchange and surface complexation involving hydroxyl, amino, and carboxyl groups. This study demonstrates S. fusiforme 's potential as an efficient biosorbent for uranium removal.