过氧乙酸是一种新兴的用于废水净化的氧化剂和消毒剂。在这项研究中,我们首先开发了一个全面而准确的模型来阐明反应机理并模拟过乙酸的反应动力学(PAA,基于实验结果和文献的CH3C(=O)OOH)被氯化物(Cl-)活化。多种多样的实验方法(例如,淬火实验,探针化合物降解,电子顺磁共振(EPR)测量)和动力学模型用于确定反应性物种。因此,以碳为中心的自由基和游离氯反应性物质(Cl2和HClO)致力于PAA/Cl-系统中的BPA降解。碳为中心的基团CH3C(=O)OO•,CH3C(=O)O•,CH3OO•,和·CH3极大地加速了BPA的降解,其相应的kCH3C(=O)OO·动力学,BPA=2×108M-1s-1,kCH3C(=O)O•,BPA=2×107M-1s-1,k•CH3,BPA=2×106M-1s-1和kCH3OO•,BPA=2×104M-1s-1。溶解的Cl2(l)物种对于用kCl2降解BPA也很重要,BPA为2×107M-1s-1,远高于kHClO的HClO/ClO-,BPA=1.2×101M-1s-1和kClO-,BPA=9×10-3M-1s-1。虽然游离氯倾向于将BPA转化为雌激素氯化有机产品,以碳为中心的自由基对BPA的主要降解导致无氯产物,减少含盐废水处理过程中消毒副产物的产生。这项研究提高了PAA/Cl-系统中反应动力学和机理以及反应性物种生成的知识。
Peracetic acid is an emerging oxidant and disinfectant for wastewater purification. In this study, we first developed a comprehensive and accurate model to elucidate the reaction mechanisms and simulate reaction kinetics of peracetic acid (PAA, CH3C(=O)OOH) activated by chloride (Cl-) based on experimental results and literature. A diversity of experiments methods (e.g., quenching experiments, probe compounds degradation, electron paramagnetic resonance (EPR) measurements) and kinetic modeling were used to determine the reactive species. As a result, carbon-centered radicals and free chlorine reactive species (Cl2 and HClO) were devoted to BPA degradation in the PAA/Cl- system. The carbon-centered radicals CH3C(=O)OO•, CH3C(=O)O•, CH3OO•, and •CH3 greatly accelerated BPA degradation with their corresponding kinetics of kCH3C(=O)OO•, BPA = 2 × 108 M-1 s-1, kCH3C(=O)O•, BPA = 2 × 107 M-1 s-1, k•CH3, BPA = 2 × 106 M-1 s-1 and kCH3OO•, BPA = 2 × 104 M-1 s-1. Dissolved Cl2(l) species was also important for BPA degradation with kCl2, BPA of 2 × 107 M-1 s-1, much higher than HClO/ClO- of kHClO, BPA = 1.2 × 101 M-1 s-1 and kClO-, BPA = 9 × 10-3 M-1 s-1. While free chlorine tends to transform BPA to estrogenic chlorinated organic products, the primary degradation of BPA by carbon-centered radicals results in chlorine-free products, reducing the production of disinfection byproducts during the treatment of saline wastewater. This study improves the knowledge of reaction kinetics and mechanism and reactive species generation in the PAA/Cl- system.