Efficient removal of uranium (VI) by nano-manganese oxide materials: A synthetic experimental and mechanism studies

Three kinds of nano-manganese oxide materials were prepared at different temperature (500, 600 and 700 degrees C) using chitosan as the template agent. The results showed that there was no sintering and ag-glomeration in the calcination of nano-manganese oxide at 600 degrees C, while the manganese oxide material calcined at 700 degrees C showed pore collapse and agglomeration and the template agent was incompletely removed in the manganese oxide material calcined at 500 degrees C. The adsorption properties of uranium (VI) on the three manganese oxide materials were investigated. The experimental results showed that the adsorption behavior conformed to the pseudo-second-order kinetics and Langmuir isotherm models, revealing that the adsorption behavior of uranium (VI) on manganese oxide materials was a uniform and monolayer chemical adsorption process. The adsorption capacity of MnO-600 was 635.4 mg/g and the adsorption efficiency was above 90% after five cycles. In conclusion, the novel manganese oxide materials would have a prospect for application in wastewater treatment. (C) 2021 Elsevier B.V. All rights reserved.