Wang Zhe, Huang Ying, Yang Jian, Li Yongsheng, Zhuang Qixin, Gu Jinlou
Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237, China.
Dalton Trans. 2017 Jun 13;46(23):7412-7420. doi: 10.1039/c7dt01084b.
The primary pollutant, radioactive iodine (I), has become a worldwide concern due to its serious ill effects of radiotoxicity on human health. Therefore, it is of great significance to develop novel adsorbents for effectively eliminating I from nuclear waste. Herein, we reported a Zr-based MOF adsorbent constructed by utilizing pyridine-containing pyridine-dicarboxylic acid (PYDC) as organic ligands (UiO-66-PYDC) as well as active sites for the efficient removal of I. UiO-66-PYDC MOFs were synthesized by a hydrothermal strategy and featured good chemical and thermal stabilities, endowing them with the ability to work in harsh environments. The abundant and inherent pyridine moieties in the developed adsorbent worked as active adsorption sites to capture I. The correlation between the most significant parameters such as the contact time, adsorbate concentration, and reusability was optimized, and the interaction mechanism between I and UiO-66-PYDC was investigated in detail. As for the current adsorbent, a pseudo-second order rate equation was used to explain the removal kinetics, and the Langmuir model exhibited a better fit to the adsorption isotherm than the Freundlich model. Thanks to the strong affinity of PYDC ligands to I and high porosity, the adsorption capacities of UiO-66-PYDC for I could reach as high as 1250 mg g, which was much higher than those of many other reported MOFs. Additionally, the UiO-66-PYDC MOFs exhibited excellent renewable adsorption properties, prefiguring their great promise as green adsorbents for I removal in nuclear waste management.
主要污染物放射性碘（I）因其对人体健康具有严重的放射毒性不良影响而成为全球关注的问题。因此，开发新型吸附剂以有效去除核废料中的碘具有重要意义。在此，我们报道了一种基于锆的金属有机框架吸附剂，它是利用含吡啶的吡啶二羧酸（PYDC）作为有机配体构建而成（UiO-66-PYDC），具有高效去除碘的活性位点。UiO-66-PYDC金属有机框架通过水热法合成，具有良好的化学和热稳定性，使其能够在恶劣环境中发挥作用。所开发的吸附剂中丰富的固有吡啶基团作为活性吸附位点来捕获碘。优化了诸如接触时间、吸附质浓度和可重复使用性等最重要参数之间的相关性，并详细研究了碘与UiO-66-PYDC之间的相互作用机制。对于当前的吸附剂，使用伪二级速率方程来解释去除动力学，并且与弗伦德里希模型相比，朗缪尔模型对吸附等温线的拟合效果更好。由于PYDC配体对碘具有很强的亲和力以及高孔隙率，UiO-66-PYDC对碘的吸附容量可高达1250 mg/g，这比许多其他已报道的金属有机框架要高得多。此外，UiO-66-PYDC金属有机框架表现出优异的可再生吸附性能，预示着它们在核废料管理中作为去除碘的绿色吸附剂具有巨大潜力。
