Key Laboratory of the Three Gorges Reservoir Regions Eco-Environment, Ministry of Education, Chongqing University, Chongqing, 400045, China.
State Key Laboratory of Pollution Control and Resources Reuse, Tongji University, Shanghai, 200092, China.
J Hazard Mater. 2021 Jan 15;402:123720. doi: 10.1016/j.jhazmat.2020.123720. Epub 2020 Aug 19.
The potential risks of sono-induced nitrosation and nitration side reactions and consequent toxic nitrogenous byproducts were first investigated via sono-degradation of diphenylamine (DPhA) in this study. The kinetic models for overall DPhA degradation and the formation of nitrosation byproduct (N-nitrosodiphenylamine, NDPhA) and nitration byproducts (2-nitro-DPhA and 4-nitro-DPhA) were well established and fitted (R > 0.98). Nitrosation contributed much more than nitration (namely, 43.3 - 47.3 times) to the sono-degradation of DPhA. The contribution of sono-induced nitrosation ranged from 0.4 to 56.6% at different conditions. The maximum NDPhA formation rate and the contribution of sono-induced nitrosation were obtained at 600 and 200 kHz, respectively, as ultrasonic frequencies at 200 to 800 kHz. Both NDPhA formation rate and the contribution of sono-induced nitrosation increased with increasing power density, while decreased with increasing initial pH and DPhA concentration. PO, HCO, NH and Fe presented negative impacts on sono-induced nitrosation in order of HCO >> Fe > PO > NH, while Br exhibited a promoting effect. The mechanism of NDPhA formation via sono-induced nitrosation was first proposed.
本研究首次通过超声降解二苯胺（DPhA）来研究超声诱导的亚硝化和硝化副反应及其产生的有毒含氮副产物的潜在风险。建立了 DPhA 总体降解和亚硝化副产物（N-亚硝基二苯胺，NDPhA）和硝化副产物（2-硝基-DPhA 和 4-硝基-DPhA）形成的动力学模型，并进行了拟合（R > 0.98）。亚硝化对 DPhA 的超声降解贡献远大于硝化（即 43.3-47.3 倍）。在不同条件下，超声诱导亚硝化的贡献范围为 0.4-56.6%。在 200 至 800 kHz 的超声频率下，分别在 600 和 200 kHz 时获得了最大的 NDPhA 生成速率和超声诱导亚硝化的贡献。NDPhA 生成速率和超声诱导亚硝化的贡献均随功率密度的增加而增加，随初始 pH 值和 DPhA 浓度的增加而降低。PO、HCO、NH 和 Fe 对超声诱导亚硝化的影响依次为 HCO > Fe > PO > NH，而 Br 则表现出促进作用。首次提出了通过超声诱导亚硝化形成 NDPhA 的机制。
