Department of Environmental Science and Technology, Beijing University of Chemical Technology, Beijing 100029, PR China.
Department of Environmental Science and Technology, Beijing University of Chemical Technology, Beijing 100029, PR China.
J Hazard Mater. 2021 Mar 15;406:124305. doi: 10.1016/j.jhazmat.2020.124305. Epub 2020 Oct 19.
Montmorillonite supported nanoscale zero-valent iron (MMT-nZVI) was prepared and proved to be able to induce the heterogenous Fenton process for better removal of 2,3',4,5-tetrachlorobiphenyl (PCB67) in a long-term polluted soil. PCB67 removal depended highly on the dosages of MMT-nZVI and HO, and the initial pH, with the highest removal rate of 76.38% at conditions of HO 45.99 g·kg, MMT-nZVI 29.88 g·kg and initial pH 3.5 after 80 min of reaction. Furthermore, PCB67 could be removed in a wider pH range (from 3.5 to near neutrality), with a loss of 13.6% in removal rate at neutral pH. With an activation energy of 21.4 kJ·mol, the degradation of PCB67 was an endothermic and diffusion-controlled process and followed the pseudo-first-order kinetics. That Fe was supplied through aerobic corrosion of MMT-nZVI to activate HO for·OH production was the possible mechanism of PCB67 degradation, leading to complete mineralization of PCB67 through two proposed pathways, with the intermediates of ethylbenzene and 3-hepten-2-one, as well as dibutyl phthalate and butyl acetate respectively.
蒙脱土负载纳米零价铁（MMT-nZVI）被制备并证明能够引发非均相芬顿过程，以更好地去除长期污染土壤中的 2,3',4,5-四氯联苯（PCB67）。PCB67 的去除高度依赖于 MMT-nZVI 和 HO 的剂量以及初始 pH 值，在 HO 45.99 g·kg、MMT-nZVI 29.88 g·kg 和初始 pH 值 3.5 的条件下，反应 80 min 后，去除率最高可达 76.38%。此外，PCB67 可以在更宽的 pH 范围内（从 3.5 到接近中性）被去除，在中性 pH 值时，去除率损失 13.6%。PCB67 的降解活化能为 21.4 kJ·mol，是一个吸热和扩散控制的过程，遵循准一级动力学。Fe 通过 MMT-nZVI 的需氧腐蚀提供，以激活 HO 生成·OH，这可能是 PCB67 降解的机制，导致 PCB67 通过两种提出的途径完全矿化，中间体分别为乙苯和 3-庚烯-2-酮，以及邻苯二甲酸二丁酯和乙酸丁酯。
