College of Environmental Science and Engineering, Donghua University, Shanghai 201620, PR China.
College of Environmental Science and Engineering, Donghua University, Shanghai 201620, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China.
J Hazard Mater. 2021 Jun 5;411:125050. doi: 10.1016/j.jhazmat.2021.125050. Epub 2021 Jan 6.
The limited production of Cu in the Cu/PMS processes constrained its large-scan application for the elimination of organic pollutants. In this study, molybdenum powder (Mo) was applied as the co-catalyst to improve the degradation of 2,4-dichlorophenol (2,4-DCP) in Cu/PMS system at pH 5.6. By the assistance of Mo, Cu was rapidly reduced to Cu which exhibited super activity for the peroxymonosulfate (PMS) activation. Compared with Cu/PMS processes, the PMS decomposition rate and 2,4-DCP degradation efficiency respectively increased by 62.1% and 83.6% in the Mo co-catalytic Cu/PMS system after reaction for 20 min. The degradation of 2,4-DCP was completed via both the free radical and non-radical pathways and the free radicals rather than Cu contributed most to the reaction. In contrast to fresh Mo, the ratio of Mo increased and Mo decreased in the used Mo powder, due to the oxidation of Mo by Cu and/or ∙OH and the reduction of Mo by O∙. Additionally, the coexistence of Cl and humic acid with low concentrations showed little effects on the Mo/Cu/PMS system while HCO presented an obvious depression for 2,4-DCP degradation. During five cycling runs, all the degradation rates were higher than 92.8%, indicating the good stability of Mo/Cu/PMS system.
在 Cu/PMS 工艺中，Cu 的产量有限，限制了其在消除有机污染物方面的大规模应用。在这项研究中，钼粉 (Mo) 被用作共催化剂，以提高 pH 值为 5.6 时 Cu/PMS 体系中 2,4-二氯苯酚（2,4-DCP）的降解效果。在 Mo 的辅助下，Cu 被迅速还原为 Cu，Cu 对过一硫酸盐（PMS）具有超强的活化作用。与 Cu/PMS 工艺相比，在 Mo 共催化 Cu/PMS 体系中，PMS 的分解速率和 2,4-DCP 的降解效率分别在 20 min 后提高了 62.1%和 83.6%。2,4-DCP 的降解是通过自由基和非自由基途径进行的，而在反应中起主要作用的是自由基而不是 Cu。与新鲜 Mo 相比，使用后的 Mo 粉末中 Mo 的比例增加，Mo 的比例减少，这是由于 Cu 和/或 ∙OH 对 Mo 的氧化以及 O∙对 Mo 的还原。此外，低浓度的 Cl 和腐殖酸的共存对 Mo/Cu/PMS 体系几乎没有影响，而 HCO 对 2,4-DCP 的降解有明显的抑制作用。在五次循环运行中，所有的降解率均高于 92.8%，表明 Mo/Cu/PMS 体系具有良好的稳定性。
