Earth Science Frontiers ›› 2022, Vol. 29 ›› Issue (3): 217-226.DOI: 10.13745/j.esf.sf.2022.1.30

Previous Articles     Next Articles

Adsorption and transport of uranium in porous sandstone media

CUI Di1(), YANG Bing2, GUO Huaming1,*(), LIAN Guoxi2, SUN Juan2   

  1. 1. School of Water Resources and Environment & MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, China University of Geosciences (Beijing), Beijing 100083, China
    2. The Fourth Research and Design Engineering Corporation of CNNC, Shijiazhuang 050021, China
  • Received:2021-12-02 Revised:2022-01-21 Online:2022-05-25 Published:2022-04-28
  • Contact: GUO Huaming


After the decommissioning of a in-situ leach uranium mining site, residual uranium leaching fluid in the aquifer migrates and diffuses downstream posing pollution risks to the surrounding groundwater. In this study, a series of batch and column experiments were designed to investigate the adsorption and migration behavior of uranium in aquifer sandstone in an in-situ leach uranium mining area in northern China. In batch experiments, uranium adsorption on sandstone reached equilibrium within 12 h, and in the process a positive correlation between the initial uranium concentration and sandstone’s uranium adsorption capacity was observed. It was found that the uranium adsorption process was endothermic and the increase in temperature was beneficial for uranium adsorption. The pH of the eluent and HCO 3 - concentration have a strong influence on uranium adsorption. Maximum uranium adsorption was reached at around neutral pH, and higher HCO 3 - concentration led to lower level of adsorption. These effects are due to the alteration of uranium complexation in the solution and the surface charge properties of sandstone. In column experiments, pH, uranium concentration, flow rate, and HCO 3 - concentration were the most important factors affecting uranium migration. Weaker acidity (pH≤7) was found to be associated with fewer late uranium breakthrough in the sandstone column; whereas higher uranium concentration, flow rate, and HCO 3 - concentration might cause early uranium breakthrough. The two-point non-equilibrium model could well describe the uranium migration process in the sandstone column under variable conditions. The partition coefficients obtained from batch experiments were 1.1-6.6 fold higher than those obtained from column experiments. According to the aquifer characteristics and hydrogeochemical characteristics, we suggest that the distribution coefficient of 48.1 mL/g would be suitable for describing uranium migration in sandstone aquifers in the study area. Overall, this study provided a theoretical basis for the reactive transport process and for the natural remediation of polluted groundwater in the in-situ leaching uranium mining areas.

Key words: groundwater, uranium, Adsorption, column experiments, two-site chemical non-equilibrium model, partition coefficient

CLC Number: