Sorption of U(VI) ions from aqueous solution by eggplant leaves: Isotherm, kinetics and thermodynamics studies

Highlights: • Eggplant leaves are used as sorbent for removal U (VI) ions from aqueous solutions. • The sorption capacity of Eggplant leaves reached 110.97 mg/g. • Loaded biomass has good regeneration with 1.5 M HNO₃. • Excellent ability to be reused up to 9 cycles. The research aims to utilize eggplant (Solanum melongena) leaves to remove and recover U(IV) ions from aqueous solutions. The biomass was characterized by SEM, FTIR and EDS analyses. Eggplant leaves appeared a maximum U(VI) uptake up to 99.87% with sorption capacity:110.97 mg/g at pH 5, 0.09 g dose, 28 °C and 50 min in the batch sorption system. The nonlinear assessment of isotherm and kinetics showed that the sorption system was fitted well by the Freundlich model and the pseudo first-order kinetic model. Also, the thermodynamic study displayed an exothermic of the uptake process. Likewise, the sorption-desorption cycle showed the good stability of eggplant leaves structure up to 9 cycles. The high adsorption capacity, low cost, good stability and biodegradable properties of eggplant leaves make it a good adsorbent for removing and recovering U(VI) ions from aqueous solutions.