Li Defenna, Pan Cong, Zong Yang, Wu Deli, Ding Yaobin, Wang Chengjun, Wang Shaobin, Crittenden John C
College of Resources and Environmental Science, South-Central Minzu University, Wuhan 430074, PR China.
State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science & Engineering, Tongji University, Shanghai 200092, PR China.
Environ Sci Technol. 2023 Aug 15;57(32):12094-12104. doi: 10.1021/acs.est.3c02582. Epub 2023 Jul 25.
In this study, Ru(III) ions were utilized to activate periodate (PI) for oxidation of trace organic pollutants (TOPs, e.g., carbamazepine (CBZ)). The Ru(III)/PI system can significantly promote the oxidation of CBZ in a wide initial pH range (3.0-11.0) at 1 μM Ru(III), showing much higher performance than transition metal ions (i.e., Fe(II), Co(II), Zn(II), Fe(III), Cu(II), Ni(II), Mn(II), and Ce(III)) and noble metal ion (i.e., Ag(I), Pd(II), Pt(II), and Ir(III)) activated PI systems. Probe experiments, UV-vis spectra, and X-ray absorption near-edge structure (XANES) spectra confirmed high-valent Ru-oxo species (Ru(V)=O) as the dominant oxidant in the process. Because of the dominant role of Ru(V)=O, the Ru(III)/PI process exhibited a remarkable selectivity and strong anti-interference in the oxidation of TOPs in complex water matrices. The Ru(V)=O species can undertake 1-e and 2-e transfer reactions via the catalytic cycles of Ru(V)=O → Ru(IV) → Ru(III) and Ru(V)=O → Ru(III), respectively. The utilization efficiency of PI in the Ru(III)/PI process for the oxidation of TOPs can approach 100% under optimal conditions. PI stoichiometrically transformed into IO without production of undesired iodine species (e.g., HOI and I). This study developed an efficient and environmentally benign advanced oxidation process for rapid removal of TOPs and enriched understandings on reactivity of Ru(V)=O and Ru catalytic cycles.
在本研究中，利用Ru(III)离子活化高碘酸盐（PI）以氧化痕量有机污染物（TOPs，如卡马西平（CBZ））。Ru(III)/PI体系在1 μM Ru(III)浓度下，能在较宽的初始pH范围（3.0 - 11.0）内显著促进CBZ的氧化，表现出比过渡金属离子（即Fe(II)、Co(II)、Zn(II)、Fe(III)、Cu(II)、Ni(II)、Mn(II)和Ce(III)）以及贵金属离子（即Ag(I)、Pd(II)、Pt(II)和Ir(III)）活化的PI体系更高得多的性能。探针实验、紫外可见光谱和X射线吸收近边结构（XANES）光谱证实高价Ru-氧物种（Ru(V)=O）是该过程中的主要氧化剂。由于Ru(V)=O起主导作用，Ru(III)/PI过程在复杂水基质中TOPs的氧化方面表现出显著的选择性和强抗干扰能力。Ru(V)=O物种可分别通过Ru(V)=O → Ru(IV) → Ru(III)和Ru(V)=O → Ru(III)的催化循环进行单电子和双电子转移反应。在最佳条件下，Ru(III)/PI过程中PI用于氧化TOPs的利用效率可接近100%。PI按化学计量转化为IO，不产生不需要的碘物种（如HOI和I）。本研究开发了一种高效且环境友好的高级氧化工艺，用于快速去除TOPs，并丰富了对Ru(V)=O反应活性和Ru催化循环的认识。
