Laboratory of Environmental Technology, INET, Tsinghua University, Beijing, 100084, China; Energy Science Building, INET, Tsinghua University, Beijing, 100084, China.
Laboratory of Environmental Technology, INET, Tsinghua University, Beijing, 100084, China; Beijing Key Laboratory of Radioactive Wastes Treatment, Tsinghua University, Beijing, 100084, China.
Chemosphere. 2023 Mar;317:137889. doi: 10.1016/j.chemosphere.2023.137889. Epub 2023 Jan 16.
In nuclear industry, tributyl phosphate (TBP) is used as organic extracting solvent to separate uranium and plutonium. The spent TBP is finally discarded as the radioactive organic waste, which should be treated due to its potential risk. In this study, TBP degradation by Fenton oxidation was investigated in detail, including the optimization of operational conditions, degradation kinetics and degradation products. The optimal conditions for TBP degradation (per 10 ml) by Fenton oxidation was: 95 °C, pH 2, 150 ml 30% HO, and 105 ml 0.2 M Fe(II). HO was continuously added with the flow rate of 0.5 ml/min, Fe(II) was intermittently added with the flow rate of 3 ml/10 min. The oil phase volume decreased with time and completely disappeared at the third hour. In contrast, the COD in water phase increased firstly and then decreased. At the end of the experiments, the COD achieved 23.8 g/L. The detection of phosphorus in water phase further confirmed the decomposition of TBP. Mono-butyl phosphate and di-butyl phosphate were identified as the intermediate products of TBP degradation. In addition, other four degradation products with the same m/z of 154 were identified, which may be derived from the hydroxylation of mono-butyl phosphate and di-butyl phosphate. Based on the degradation products, the degradation pathway of TBP was proposed. This study could provide an insight into the TBP degradation by Fenton oxidation, and an potential strategy for treating the spent radioactive organic solvent.
在核工业中，磷酸三丁酯（TBP）被用作有机萃取溶剂来分离铀和钚。用过的 TBP 最终被丢弃为放射性有机废物，由于其潜在风险，应进行处理。在这项研究中，详细研究了 Fenton 氧化法降解 TBP，包括操作条件、降解动力学和降解产物的优化。Fenton 氧化法降解 TBP 的最佳条件（每 10ml）为：95°C，pH2，150ml30%HO 和 105ml0.2MFe(II)。HO 以 0.5ml/min 的流速连续添加，Fe(II)以 3ml/10min 的流速间歇添加。油相体积随时间减少，在第三个小时完全消失。相比之下，水相中 COD 先增加后减少。实验结束时，COD 达到 23.8g/L。水中磷的检测进一步证实了 TBP 的分解。单丁基磷酸酯和二丁基磷酸酯被鉴定为 TBP 降解的中间产物。此外，还鉴定出另外四个具有相同 m/z 值为 154 的降解产物，它们可能是单丁基磷酸酯和二丁基磷酸酯的羟基化产物。基于降解产物，提出了 TBP 的降解途径。这项研究可以深入了解 Fenton 氧化法降解 TBP，为处理放射性有机废物提供潜在策略。
