Abstract:

A novel sorbent, nano-TiO2 was employed for the removal of molybdenum and rhenium from aqueous solution in batch equilibrium experiments, in order to investigate their adsorption properties. The removal percentage of molybdenum by the sorbent is closed to 99% at the pH range of 1-8. The elution rate of molybdenum by 2mL 0.05 mol/LNaOH is closed to 97%. As rhenium is hardly adsorpted onto nano-TiO2,Molybdenum and rhenium can be separated. The adsorption capacities and removal percentage of Mo(VI) onto nano- TiO2 were evaluated as a function of the solution concentration and temperature. Results have been analyzed by the Langmuir, Freundlich adsorption isotherms. Adsorption isothermal data could be well interpreted by the Langmuir model. Saturated adsorption capacity increases from 11.51mg g-1 to 14.19 mg g-1 at the temperature range of 2℃～50℃。The removal percentage of Re(VII) by the actived carbon is closed to 99% at the pH range of 1-10. The results showed that the equilibrium time of nano-TiO2 adsorption Re(VII) is 5 min, the elution rate of Re(VII) with strong ammonia is 96% . Adsorption isothermal data could be well interpreted by the Freundlich model. The kinetic experimental data of Re(VII) properly correlated with the second-order kinetic model.

Key words: Mo(Ⅵ),Re(Ⅶ),nano-TiO₂,actived carbon,adsorption,elution