Abstract:
The magnetic mesoporous TiO
2/graphene oxide (Fe
3O
4@TiO
2/GO) composites were prepared by the synthesis of graphene oxide (GO), nano Fe
3O
4 and tetrabutyl titanate (TBOT), then the Fe
3O
4@TiO
2/GO composites were used to treat U(Ⅵ)-containing waste water at a concentration of 10 mg·L
-1. The effects of mass fraction of GO in Fe
3O
4@TiO
2/GO composites, initial pH of solution, the dosage of Fe
3O
4@TiO
2/GO composites, reaction time, initial uranium concentration and coexisting ions on U(Ⅵ) adsorption on Fe
3O
4@TiO
2/GO composites were investigated. The results show that the Fe
3O
4@TiO
2/GO composites has the best adsorption for U(Ⅵ) when the pH value is 6, the mass fraction of GO is 60wt% and the Fe
3O
4@TiO
2/GO composites dosage is 10 mg, under the same conditions, the adsorption capacity of U(Ⅵ) is 10.99 mg·g
-1 and 1.91 mg·g
-1 higher than that of Fe
3O
4@TiO
2 composites and GO, respectively. The adsorption results of the Fe
3O
4@TiO
2/GO composites are balanced at 180 min, and the pseudo-second-order kinetics model and the Freundlich adsorption isotherm model are good descriptions of the adsorption of the Fe
3O
4@TiO
2/GO composites for U(Ⅵ) process. The results of desorption experiments show that the adsorption efficiency of the Fe
3O
4@TiO
2/GO composites for U(Ⅵ) remains as high as 90.86% after 5 cycles of adsorption-desorption, indicating that the Fe
3O
4@TiO
2/GO composites have higher recycling performance.