Kinetics and isothermal adsorption of U(VI) in aqueous solution by nano-Ni0

The nanoscale zero-valent nickel (nano-Ni0) was prepared by liquid-phase reduction method and characterized by BET, XPS, FT-IR and XRD and be used to remove U(VI) from aqueous solution. The data were analyzed by the Langmuir and Freundlich models. The kinetic data were analyzed by pseudo-first-order kinetic and pseudo-second-order models. The results showed that the nano-Ni0 had a good removal efficient on U(VI), after reaction, the peaks of Ni2+ and U4+ appeared in XPS spectra, which revealed that the U(VI) was reduced to U(IV) and Ni0 was oxidated to Ni2+ and Ni3+. The kinetics and isothermal models showed that the adsorption process was surface monolayer adsorption and was controlled by chemical adsorption rate.