Hydrothermal fabrication of amino functionalized lotus seedpods-derived biochar for efficient removal of uranium (VI)

In this work, amino functionalized lotus seedpods-derived biochar (LSBC-NH₂) was prepared for the removal of uranium (VI) from aqueous solution by using natural lotus seedpods as raw material and urea as nitrogen source through hydrothermal method. LSBC-NH₂ showed a very thin sheet structure with rough porous surface and cluster structure and good thermal stability. Kinetics, isotherms and thermodynamics studies demonstrated that the adsorption of uranium (VI) by LSBC-NH₂ was a spontaneous, endothermic, and single-layer chemisorption process, and the maximum uranium (VI) adsorption capacity on LSBC-NH₂ could reach 367.99 mg g^-1. Adsorption mechanism showed that the adsorption process of LSBC-NH₂ for uranium (VI)was involved in amino, carboxyl and hydroxyl groups in LSBC-NH₂. (author)