Zhu Simeng, Xiao Pengyu, Wang Xue, Liu Yang, Yi Xianliang, Zhou Hao
Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Ocean Science and Technology, Panjin Campus, Dalian University of Technology, China.
Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Ocean Science and Technology, Panjin Campus, Dalian University of Technology, China.
J Hazard Mater. 2022 Apr 5;427:127938. doi: 10.1016/j.jhazmat.2021.127938. Epub 2021 Nov 27.
Heterogeneous sulfate radical-based advanced oxidation processes (SR-AOPs) have been widely reported over the last decade as a promising technology for pollutant removal from wastewater. In this study, a novel peroxymonosulfate (PMS) activator was obtained by visible-light-driven Mn(II) oxidation in the presence of nitrate. The photochemically synthesized manganese oxides (PC-MnO) were polymorphic amorphous nanoparticles and nanorods, with an average oxidation state of approximately 3.0. It possesses effective PMS activation capacity and can remove 20 mg L acid organic II (AO7) within 30 min. The AO7 removal performance of PC-MnO was slightly decreased in natural waterbodies and in the presence of CO, while it showed an anti-interference capacity for Cl, NO and humic acid. Chemical quenching, reactive oxygen species (ROS) trapping, X-ray photoelectric spectroscopy (XPS), in-situ Raman spectroscopy, and electrochemical experiments supported a nonradical mechanism, i.e., electron transfer from AO7 to the metastable PC-MnO-PMS complex, which was responsible for AO7 oxidation. The PC-MnO-PMS system also showed substrate preferences based on their redox potentials. Moreover, PC-MnO could activate periodate (PI) but not peroxydisulfate (PDS) or HO. Overall, this study provides a new catalyst for PMS activation through a mild and green synthesis approach.
在过去十年中，基于硫酸根自由基的非均相高级氧化工艺（SR-AOPs）作为一种从废水中去除污染物的有前景的技术已被广泛报道。在本研究中，通过在硝酸盐存在下可见光驱动的Mn(II)氧化获得了一种新型过一硫酸盐（PMS）活化剂。光化学合成的锰氧化物（PC-MnO）为多晶型无定形纳米颗粒和纳米棒，平均氧化态约为3.0。它具有有效的PMS活化能力，可在30分钟内去除20 mg L酸性有机染料II（AO7）。在天然水体和存在CO的情况下，PC-MnO对AO7的去除性能略有下降，而它对Cl、NO和腐殖酸具有抗干扰能力。化学猝灭、活性氧物种（ROS）捕获、X射线光电子能谱（XPS）、原位拉曼光谱和电化学实验支持了一种非自由基机制，即电子从AO7转移到亚稳的PC-MnO-PMS络合物，这是AO7氧化的原因。PC-MnO-PMS体系还根据底物的氧化还原电位表现出底物偏好。此外，PC-MnO可以活化高碘酸盐（PI），但不能活化过二硫酸盐（PDS）或过氧化氢（HO）。总体而言，本研究通过一种温和且绿色的合成方法为PMS活化提供了一种新型催化剂。
