| To effectively remove uranium-containing water from uranium tailing ponds, biochar (BC) was prepared by calcining bamboo, and then modified with potassium phosphate to obtain phosphorus-based biochar (PBC). The results of batch tests showed that the adsorption performance of PBC on U(VI) was better than that of BC, and the removal rate of U(VI) by PBC could reach 99 % when the initial concentration of U(VI) was 10 mg/L, the adsorbent dosage was 0.1 g/L, the temperature was 30 ℃, and the reaction time was 2 h. The adsorption process of BC and PBC on U(VI) was in accordance with quasi-two-stage adsorption kinetic model and the Langmuir adsorption isotope model. The adsorption processes of BC and PBC on U(VI) were consistent with the quasi-secondary adsorption kinetic model and the Langmuir adsorption isotherm model, and both were spontaneous monolayer uniform chemical adsorption, and the maximal adsorption capacity of PBC on U(VI) was 803.64 mg/g, which was about 10 times of that of BC. The results of the interference ion test showed that the adsorption process of PBC on U(VI) was relatively stable. After four adsorption-desorption tests, PBC still had a good adsorption effect on U(VI). The results of characterization by Fourier infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) showed that the removal mechanism of PBC on U(VI) was mainly complex precipitation and ion exchange. |