School of Ecology and Environment, Northwestern Polytechnical University, 710129 Xi'an, PR China.
School of Ecology and Environment, Northwestern Polytechnical University, 710129 Xi'an, PR China.
J Hazard Mater. 2022 Jun 15;432:128723. doi: 10.1016/j.jhazmat.2022.128723. Epub 2022 Mar 17.
Removing and recovering uranium (U) from U-mining wastewater would be appealing, which simultaneously reduces the adverse environmental impact of U mining activities and mitigates the depletion of conventional U resources. In this study, we demonstrate the application of a constant-voltage electrochemical (CVE) method for the removal and recovery of U from U-mining wastewater, in an ambient atmosphere. The effects of operation conditions were elucidated in synthetic U-bearing water experiments, and the cell voltage and the ionic strength were found to play important roles in both the U extraction kinetics and the operation cost. The mechanistic studies show that, in synthetic U-bearing water, the CVE U extraction proceeds exclusively via a single-step one-electron reduction mechanism, where pentavalent U is the end product. In real U-mining wastewater, the interference of water matrices led to the disproportionation of the pentavalent U, resulting in the formation of tetravalent and hexavalent U in the extraction products. The U extraction efficacy of the CVE method was evaluated in real U-mining wastewater, and results show that the CVE U extraction method can be efficient with operation costs ranging from $0.55/kgU ~ $64.65/kgU, with varying cell voltages from 1.0 V to 4.0 V, implying its feasibility from the economic perspective.
从铀矿废水中去除和回收铀（U）将是吸引人的，这可以同时减少铀开采活动的不利环境影响，并缓解常规铀资源的枯竭。在这项研究中，我们展示了在环境气氛中使用恒压电化学（CVE）方法从铀矿废水中去除和回收铀的应用。在合成含铀水中的实验中阐明了操作条件的影响，并且发现电池电压和离子强度在铀提取动力学和操作成本方面都起着重要作用。机理研究表明，在合成含铀水中，CVE 铀提取仅通过单电子还原机制进行，其中五价铀是最终产物。在实际的铀矿废水中，水基质的干扰导致五价铀的歧化，导致提取产物中形成四价和六价铀。在实际的铀矿废水中评估了 CVE 方法的铀提取效果，结果表明，CVE 铀提取方法具有效率，操作成本范围为每公斤铀 0.55 美元至 64.65 美元，电池电压从 1.0 V 到 4.0 V 不等，这表明从经济角度来看具有可行性。
