Abstract:
To address the efficiency of removing U(Ⅵ) from water using functional materials and the susceptibility of nanoparticles to agglomeration, biochar-loaded magnetic nanocarbon hydroxyapatite (CHAP-γ-Fe
2O
3/BC) composites were prepared by dynamic oil-heating and impregnation methods using corn stover, egg shells, and magnetic γ-Fe
2O, and the experiments were carried out to investigate the performances and used for the removal of U(Ⅵ) from water. When the initial concentration of U(Ⅵ) is 5 mg/L, the dosage of CHAP-γ-Fe
2O
3/BC is 0.1 g/L, the pH value is 6, the temperature is 30℃, and the reaction time is 1 h, the experimental results show that the maximum adsorption capacity of CHAP-γ-Fe
2O
3/BC for U(Ⅵ) reaches 324.4 mg/g, and the removal rate reaches 95.93%. The proposed secondary kinetic model and Langmuir model could fit the adsorption process of CHAP-γ-Fe
2O
3/BC on U(Ⅵ) better, indicating that the monomolecular layer chemisorption is dominated. The materials are realized to attenuate the agglomeration by surface modification technique. The composite material shows good separation recovery and recyclability in the magnetic field. The characterization results of FTIR and XPS prove that the removal mechanism of uranium by this material mainly includes ion exchange, dissolution-precipitation chemisorption and surface complexation.