Adsorption of Low-Concentrated U(VI) on a Preferable Crystalline Boehmite (γ-AlOOH) in Alkaline Conditions

作者：Han, Yunwu; Xiong, Jiachun; Zhang, Hailin; Chen, Xing; Liu, Wenke; Chang, Qingqing; Li, Qian; Xie, Haijiao; Li, Guangqiang; Qin, Qingwei^*; Li, Ping^*

来源：Industrial and Engineering Chemistry Research, 2023, 62(48): 20802-20810.

DOI：10.1021/acs.iecr.3c02033

• URANIUM(VI) ADSORPTION
• AQUEOUS-SOLUTIONS
• URANYL CARBONATE
• REMOVAL
• DESORPTION
• PARAMETERS
• BENTONITE
• COMPOSITE
• SORPTION
• ZEOLITE

Contamination of uranyl ions is a severe environmental problem, and the development of a new removal method is essential for removing uranyl ions, especially in alkaline solutions of the rare earth production process. The boehmite (gamma-AlOOH) adsorbent with a large specific surface area was prepared from aluminum-containing residues. The U(VI) adsorption behavior and mechanism of gamma-AlOOH were investigated by inductively coupled plasma optical emission spectroscopy (ICP-OES), scanning electron microscopy (SEM), electron probe microanalysis (EPMA), X-ray photoelectron spectroscopy (XPS), zeta-potential, and so on. It could be found that in an alkaline solution with up to 20 mg/L U(VI), more than 94.18% U(VI) could be removed and the U(VI) in an alkaline solution could be decreased to as low as 1.16 mg/L, at 60 degrees C, 1 h with the gamma-AlOOH dosage of 20 g/L. Thermodynamic and kinetic studies showed that U(VI) adsorbed onto gamma-AlOOH was consistent with the pseudo-second-order model (R-2 = 0.999). The gamma-AlOOH adsorption of U(VI) conformed to chemisorption. The adsorption mechanism showed that UO2(OH)(4)(2-) exchanged with -OH of gamma-AlOOH. The desorption and recyclability results revealed that about 94% of U(VI) was desorbed. After five adsorption/desorption experiments, the U(VI) removal yield by gamma-AlOOH was reduced by only 17.2%. This work provided a potential to remove U(VI) by gamma-AlOOH adsorbents in an alkaline solution.

• 单位
  中国科学院