Terbuthylazine (TBA) is a widely used herbicide, and its heterogeneous reaction with OH radicals is important for assessing its potential to undergo atmospheric long-range transport and to affect the environment and public health. The apparent reaction rate coefficients obtained in different experimental investigations, however, vary by orders of magnitude depending on the applied experimental techniques and conditions. In this study, we used a kinetic multilayer model of aerosol chemistry with reversible surface adsorption and bulk diffusion (KM-SUB) in combination with a Monte Carlo genetic algorithm to simulate the measured decay rates of TBA. Two experimental data sets available from different studies can be described with a consistent set of kinetic parameters resolving the interplay of chemical reaction, mass transport, and shielding effects. Our study suggests that mass transport and shielding effects can substantially extend the atmospheric lifetime of reactive pesticides from a few days to weeks, with strong implications for long-range transport and potential health effects of these substances.

中文翻译：

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异羟基氧化，屏蔽作用及其对叔丁嗪和其他农药的大气命运的影响

特丁嗪（TBA）是一种广泛使用的除草剂，其与OH自由基的异质反应对于评估其进行大气远程运输并影响环境和公众健康的潜力非常重要。然而，根据所应用的实验技术和条件，在不同的实验研究中获得的表观反应速率系数变化了几个数量级。在这项研究中，我们结合了可逆表面吸附和本体扩散（KM-SUB）的气溶胶化学动力学多层模型，并结合了蒙特卡罗遗传算法来模拟TBA的衰减速率。可以描述来自不同研究的两个实验数据集，其中包含一致的动力学参数集，以解决化学反应，质量传输和屏蔽效应之间的相互作用。