Department of Chemistry and Chemical Engineering, LuLiang University, Lishi 033001, China.
College of Chemical and Biological Engineering, Taiyuan University of Science and Technology, Taiyuan, 030024, China E-mail:
Water Sci Technol. 2021 Apr;83(8):2001-2011. doi: 10.2166/wst.2021.103.
Rapid removal of radioactive strontium from nuclear wastewater is of great significance for environmental safety and human health. This work reports the effective adsorption of strontium ion in a stable dual-group metal-organic framework, Zr(OH)(BDC-(COOH))(SO) (Zr-BDC-COOH-SO), which contains strontium-chelating groups (-COOH and SO) and a strongly ionizable group (-COOH). Zr-BDC-COOH-SO exhibits very rapid adsorption kinetics (<5 min) and a maximum adsorption capacity of 67.5 mg g. The adsorption behaviors can be well fitted to the pseudo-second-order model and the Langmuir isotherm model. Further investigations indicate that the adsorption of Sr onto Zr-BDC-COOH-SO would not be obviously affected by solution pH and adsorption temperature. The feasible regeneration of the adsorbent was also demonstrated using a simple elution method. Mechanism investigation suggests that free -COOH contributes to the rapid adsorption based on electrostatic interaction, while the introduction of -SO significantly enhanced the adsorption capacity. Thus, these results suggest that Zr-BDC-COOH-SO is a potential candidate for Sr removal. They also introduce dual groups as an effective strategy for designing high-efficiency adsorbents.
从核废水中快速去除放射性锶对于环境安全和人类健康具有重要意义。本工作报道了一种稳定的双功能基金属有机骨架 Zr(OH)(BDC-(COOH))(SO)（Zr-BDC-COOH-SO）对锶离子的有效吸附，该骨架含有锶螯合基团（-COOH 和 -SO）和强电离基团（-COOH）。Zr-BDC-COOH-SO 表现出非常快速的吸附动力学（<5min）和 67.5mg/g 的最大吸附容量。吸附行为可以很好地拟合伪二级模型和 Langmuir 等温线模型。进一步的研究表明，Sr 在 Zr-BDC-COOH-SO 上的吸附不会受到溶液 pH 和吸附温度的明显影响。还通过简单的洗脱方法证明了吸附剂的可行再生。机理研究表明，游离的 -COOH 通过静电相互作用促进了快速吸附，而 -SO 的引入则显著提高了吸附容量。因此，这些结果表明 Zr-BDC-COOH-SO 是一种去除 Sr 的潜在候选材料。它们还引入了双功能基作为设计高效吸附剂的有效策略。
