Removal of U(VI) from aqueous solution by Al0/Ni0 bimetallic material

Abstract

The widespread use of nuclear energy has led to a growing concern over environmental pollution resulted from uranium which has prompted global attention on wastewater treatment. Zero valent aluminum and zero valent nickel metals have been used by numerous researchers both domestically and internationally to removal U(VI) from aqueous solution due to their unique chemical properties. In this work, Al⁰/Ni⁰ bimetallic material (Al⁰/Ni⁰-BM) was prepared by synchronous liquid-phase reduction method. Due to the structure of bimetallic material and synergistic effect, it exhibited a higher removal rate compared with single zero valent metal. At room temperature (25 ℃), the initial concentration of U(VI) was 20 mg/L, pH was 3.0, dosage was 0.25 g/L, and the removal rate could reach 98.90% after 60 min of reaction, well-fitting with the pseudo-second-order kinetic model, reduction model, and Langmuir isothermal adsorption model. The high removal performance was attributed to the electron transfer mechanism between material and U element and the adsorption effect of corresponding hydroxides. The thermodynamic parameters demonstrated that the adsorption of U(VI) on the Al⁰/Ni⁰-BM was an endothermic and spontaneous process controlled by physical and chemical adsorptions. And the synthesized Al⁰/Ni⁰-BM effectively improved the aggregation of zero valent metals in monomers. In conclusion, Al⁰/Ni⁰-BM showed an excellent potential for U(VI) removal from aqueous solution by zero valent bimetallic materials.