School of Resource & Environment and Safety Engineering, University of South China, Hengyang, 421001, China.
J Environ Radioact. 2022 Sep;250:106909. doi: 10.1016/j.jenvrad.2022.106909. Epub 2022 May 18.
Reduction of the migratory ability of uranium via reduction, co-precipitation or immobilization is a widely used technology for remediation of uranium contaminated groundwater (UCG). However, the re-released uranium due to environmental alterations such as oxidation, acid dissolution, or microbial decomposition limits the long-term effect of UCG remediation. Here, we developed a novel solar-powered electrochemical mineralization (SPEM) system for persistent remediation of UCG under laboratory conditions. The SPEM system incorporates uranium into magnetite crystal to achieve long-term stability of uranium. The effects of photoelectric conversion, subsurface void fraction, groundwater seepage velocity, and electrode configuration on uranium removal were systematically analyzed. The results showed that the remediation system had excellent adaptability to complex water quality and geological conditions, and could remediate large-area contamination. After 12 h of persistent treatment, the system with newly hexagonal two-dimensional electrode configuration (1A6C) reduced uranium concentration by more than 85% in simulated subsurface environment. The mineralized uranium was not re-released within continuous rinsing of treated regions using an acid solution (pH = 3.0), for 370 h. The developed method solely requires metallic iron as a raw material, which has high and long-term efficiency, is eco-friendly, simple, and widely applicable, thus reliable for the remediation of deep UCG.
通过还原、共沉淀或固定化来降低铀的迁移能力是一种广泛用于修复铀污染地下水（UCG）的技术。然而，由于氧化、酸溶解或微生物分解等环境变化，重新释放的铀限制了 UCG 修复的长期效果。在这里，我们开发了一种新型的太阳能驱动电化学矿化（SPEM）系统，用于在实验室条件下对 UCG 进行持久修复。SPEM 系统将铀纳入磁铁矿晶体中，以实现铀的长期稳定性。系统分析了光电转换、地下空隙率、地下水渗流速度和电极配置对铀去除的影响。结果表明，修复系统对复杂的水质和地质条件具有极好的适应性，并能修复大面积的污染。在持续处理 12 小时后，采用新型六边形二维电极配置（1A6C）的系统在模拟地下环境中使铀浓度降低了 85%以上。在使用 pH=3.0 的酸溶液连续冲洗处理区域的 370 小时内，矿化铀没有重新释放。所开发的方法仅需要金属铁作为原料，具有高效、长期、环保、简单和广泛适用性，因此可靠适用于深部 UCG 的修复。
