【摘要】 岩洞处置环境中，围岩作为阻滞放射性核素进入环境的最后一道屏障，其在长期处置过程中产生的围岩胶体增大了核素迁移的风险。本文以围岩胶体和处置库拟处置的Sr²⁺为研究对象，开展了围岩胶体稳定性及胶体对Sr²⁺的吸附性能研究。稳定性研究表明：pH、温度及岩洞处置库地下水中部分离子均对围岩稳定性有影响，围岩胶体在处置库地下水环境中拥有良好的稳定性能。通过吸附试验，考察了时间、pH、不同离子等因素对吸附的影响，并对其吸附动力学及吸附等温模型进行了分析。结果显示：围岩胶体吸附Sr²⁺在12 h达到平衡，平衡吸附量为41.79 mg·g^-1；碱性环境下，吸附量随pH而增大；不同离子均对围岩胶体吸附Sr²⁺有抑制作用，其阳离子抑制作用大于阴离子。围岩胶体对Sr²⁺的吸附符合准二级动力学模型及Freundlich吸附等温模型。更多还原

【Abstract】 [Background] In cave disposal environment, surrounding rock is the last barrier to prevent radionuclides from entering the environment, and the colloid of surrounding rock produced in the long-term disposal process increases the risk of radionuclides migration. [Purpose] This study aims to explore the adsorption performance of surrounding rock colloid for Sr²⁺ disposed the repository, and the stability of surrounding rock colloid. [Methods]First of all, the surrounding rock colloid sample was prepared with approximate mass concentration of 0.03 g·L-1,zeta potential of 21.53 mV and particle size of 205.7 nm. Then, the effects of time, pH value, various ions under different concentrations, and other factors on the adsorption properties, such as the zeta potential and average particle size of the surrounding rock colloids were investigated by experimental measurements. Finally, the adsorption kinetics and adsorption isothermal model were analyzed. [Results] Experimental results show that the colloid adsorption Sr²⁺ reaches equilibrium at 12 h, and the equilibrium adsorption capacity is 41.79 mg·g^-1. In alkaline environment, the adsorption capacity increases with the increase of pH. The adsorption of Sr²⁺ by colloid of surrounding rock is inhibited by different ions, and the inhibitory effect of cations is greater than that of anions.[Conclusions] Results of this study indicate that pH value, temperature and partial ions in the groundwater of the cave disposal facility all have influence on the stability of surrounding rock, and the surrounding rock colloid has good stability in the groundwater environment of the repository. The adsorption of Sr²⁺ by surrounding rock colloid conforms to the quasi-second-order kinetic model and the Freundlich adsorption isothermal model.更多还原