School of Civil and Environmental Engineering, Shenzhen Polytechnic, Shenzhen, 518055, China.
School of Civil and Environmental Engineering, Harbin Institute of Technology Shenzhen, Shenzhen, 518055, China.
Sci Rep. 2020 Dec 9;10(1):21548. doi: 10.1038/s41598-020-78468-y.
Iodinated contrast media (ICM), which was widely used in medical imaging and was difficult to remove by conventional wastewater treatment methods, attained much attention due to its potential environmental impacts. Herein, iopamidol (IPM), one typical compound of ICM, was found to be rapidly degraded by ferrous activated persulfate oxidation (Fe(II)/PS) as compared with PS or Fe(II) alone. With a persulfate concentration of 1 mmol L, n(Fe(II))/n(PS) of 1:10, and a pH of 3.0, 78% IPM was degraded within 60 min, with a degradation rate of 0.1266 min. It was demonstrated that IPM degradation and deiodination were favored by a high temperature, while affected positively by acidic and neutral conditions. Radical quenching experiments and Electron Paramagnetic Resonace (EPR) spectra showed that the combined effects of SO· and ·OH contributed dominantly to degrade IPM, while the ·OH played an essential role during the degradation reaction. Through the Discrete Fourier Transform quantum chemical calculation, the possible reaction pathways for the oxidation of IPM by ·OH are as follows: IPM-TP651-TP667-TP541-TP557, IPM-TP651-TP525-TP557, IPM-TP705-TP631-TP661, and IPM-TP705-TP735. The obtained results showed that IPM could be degraded effectively by Fe(II)/PS system, giving a promising technique for IPM removal from water.
含碘造影剂（ICM）广泛应用于医学成像，由于其潜在的环境影响，难以通过传统的废水处理方法去除，因此备受关注。本文研究了一种典型的 ICM 化合物——碘帕醇（IPM），与过硫酸盐（PS）或单独的二价铁（Fe(II)）相比，亚铁激活过硫酸盐氧化（Fe(II)/PS）可以快速降解 IPM。在过硫酸盐浓度为 1 mmol·L、n(Fe(II))/n(PS)为 1:10、pH 值为 3.0 的条件下，60 min 内 IPM 的降解率达到 78%，降解速率为 0.1266 min。实验结果表明，高温有利于 IPM 的降解和脱碘，而酸性和中性条件有利于 IPM 的降解。自由基猝灭实验和电子顺磁共振（EPR）谱表明，SO·和·OH 的协同作用对 IPM 的降解起主要作用，而·OH 在降解反应中起关键作用。通过离散傅里叶变换量子化学计算，得到·OH 氧化 IPM 的可能反应途径为：IPM-TP651-TP667-TP541-TP557、IPM-TP651-TP525-TP557、IPM-TP705-TP631-TP661 和 IPM-TP705-TP735。研究结果表明，Fe(II)/PS 体系可以有效降解 IPM，为水中 IPM 的去除提供了一种有前景的技术。
