College of Environmental Science and Engineering, Hunan University, Changsha, Hunan 410082, China.
Key Laboratory of Environmental Biology and Pollution Control, Ministry of Education, Hunan University, Changsha, Hunan 410082, China.
Environ Sci Technol. 2024 Jul 9;58(27):12179-12188. doi: 10.1021/acs.est.4c00901. Epub 2024 Jun 24.
Extensive research has been conducted on the utilization of a metal-based catalyst to activate peracetic acid (PAA) for the degradation of micropollutants (MPs) in water. Mn(II) is a commonly employed catalyst for homogeneous advanced oxidation processes (AOPs), but its catalytic performance with PAA is poor. This study showed that the environmentally friendly chelator ethylenediamine-,'-disuccinic acid (EDDS) could greatly facilitate the activation of Mn(II) in PAA for complete atrazine (ATZ) degradation. In this process, the EDDS enhanced the catalytic activity of manganese (Mn) and prevented disproportionation of transient Mn species, thus facilitating the decay of PAA and mineralization of ATZ. By employing electron spin resonance detection, quenching and probe tests, and O isotope-tracing experiments, the significance of high-valent Mn-oxo species (Mn(V)) in the Mn(II)-EDDS/PAA system was revealed. In particular, the involvement of the Mn(III) species was essential for the formation of Mn(V). Mn(III) species, along with singlet oxygen (O) and acetyl(per)oxyl radicals (CHC(O)O/CHC(O)OO), also contributed partially to ATZ degradation. Mass spectrometry and density functional theory methods were used to study the transformation pathway and mechanism of ATZ. The toxicity assessment of the oxidative products indicated that the toxicity of ATZ decreased after the degradation reaction. Moreover, the system exhibited excellent interference resistance toward various anions and humid acid (HA), and it could selectively degrade multiple MPs.
已经有大量研究致力于利用基于金属的催化剂来激活过氧乙酸（PAA），以降解水中的微量污染物（MPs）。Mn(II) 是一种常用于均相高级氧化工艺（AOPs）的催化剂，但它与 PAA 的催化性能较差。本研究表明，环境友好的螯合剂乙二胺二琥珀酸（EDDS）可以极大地促进 Mn(II)在 PAA 中的活化，从而实现完全莠去津（ATZ）降解。在这个过程中，EDDS 增强了锰（Mn）的催化活性，并防止瞬态 Mn 物种的歧化，从而促进 PAA 的衰减和 ATZ 的矿化。通过电子自旋共振检测、猝灭和探针测试以及 O 同位素示踪实验，揭示了高价 Mn-氧物种（Mn(V)）在 Mn(II)-EDDS/PAA 体系中的重要性。特别是，Mn(III)物种的参与对于 Mn(V)的形成是必不可少的。Mn(III)物种，以及单线态氧（O）和乙酰（过）氧自由基（CHC(O)O/CHC(O)OO），也部分促进了 ATZ 的降解。质谱和密度泛函理论方法被用于研究 ATZ 的转化途径和机制。氧化产物的毒性评估表明，ATZ 的毒性在降解反应后降低。此外，该体系对各种阴离子和湿酸（HA）具有出色的抗干扰能力，并且可以选择性地降解多种 MPs。
