Reactive organic carbon emissions from volatile chemical products.
Reactive organic carbon emissions from volatile chemical products.
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DOI：
10.5194/acp-21-5079-2021
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发表时间：
2021-03-31
影响因子：
6.3
通讯作者：
Pye HOT
中科院分区：
文献类型：
--
作者：
Seltzer KM;Pennington E;Rao V;Murphy BN;Strum M;Isaacs KK;Pye HOT
挥发性化学品（VCPs）是一个越来越重要的人为活性有机碳（ROC）排放源。这些来源包括日常用品，如个人护理产品、一般清洁剂、建筑涂料、杀虫剂、粘合剂和印刷油墨。在这里，我们开发VCPy，一个新的框架来模拟整个美国的VCPs的有机排放，包括区域和地方尺度的空间分配。在VCPy框架中，一种物质从VCP混合物中的蒸发是控制挥发的化合物特定理化性质和与产物蒸发相关的时间尺度的函数。我们引入两个术语来描述这些过程：蒸发时标和使用时标。使用此框架，预计2016年VCP的全国人均有机排放量为每人每年9.5千克（每人每年6.4千克C），相当于3.05 Tg（2.06 Tg C），使VCP成为美国人为有机排放的主要来源。通过蒙特卡罗分析表征了与该框架相关的不确定性和对选择参数的敏感性，得出2016年国家VCP排放量的95%置信区间为2.61-3.53 Tg（1.76-2.38 Tg C）。这一全国范围的总量与美国环保署2017年国家排放清单（NEI）大致一致;然而，县级和分类估计值可能与NEI值有很大差异。VCPy预测大约一半的县的VCP排放量高于NEI，其中5%的县的排放量高于NEI 55%。从类别上看，与NEI相比，VCPy框架的应用导致个人护理产品（150%）和油漆和涂料（25%）的排放量更高，而农药（-54%）和印刷油墨（-13%）的排放量更低。一项观测评估表明，使用VCPy框架（归一化平均偏差为-13%，r =0.95），VCPs的关键物种排放量得到了高保真再现。在全部门范围内，VCP的有效二次有机气溶胶产量和最大增量反应性分别为5.3%（按质量计）和1.58 gO 3 g−1，表明VCP是城市环境中一个重要的二次污染源，但迄今为止可能代表性不足。
Volatile chemical products (VCPs) are an increasingly important source of anthropogenic reactive organic carbon (ROC) emissions. Among these sources are everyday items, such as personal care products, general cleaners, architectural coatings, pesticides, adhesives, and printing inks. Here, we develop VCPy, a new framework to model organic emissions from VCPs throughout the United States, including spatial allocation to regional and local scales. Evaporation of a species from a VCP mixture in the VCPy framework is a function of the compound-specific physiochemical properties that govern volatilization and the timescale relevant for product evaporation. We introduce two terms to describe these processes: evaporation timescale and use timescale. Using this framework, predicted national per capita organic emissions from VCPs are 9.5 kg per person per year (6.4 kg C per person per year) for 2016, which translates to 3.05 Tg (2.06 Tg C), making VCPs a dominant source of anthropogenic organic emissions in the United States. Uncertainty associated with this framework and sensitivity to select parameters were characterized through Monte Carlo analysis, resulting in a 95 % confidence interval of national VCP emissions for 2016 of 2.61–3.53 Tg (1.76–2.38 Tg C). This nationwide total is broadly consistent with the U.S. EPA’s 2017 National Emission Inventory (NEI); however, county-level and categorical estimates can differ substantially from NEI values. VCPy predicts higher VCP emissions than the NEI for approximately half of all counties, with 5 % of all counties having greater than 55 % higher emissions. Categorically, application of the VCPy framework yields higher emissions for personal care products (150 %) and paints and coatings (25 %) when compared to the NEI, whereas pesticides (−54 %) and printing inks (−13 %) feature lower emissions. An observational evaluation indicates emissions of key species from VCPs are reproduced with high fidelity using the VCPy framework (normalized mean bias of −13 % with r =0.95). Sector-wide, the effective secondary organic aerosol yield and maximum incremental reactivity of VCPs are 5.3 % by mass and 1.58 gO3 g−1, respectively, indicating VCPs are an important, and likely to date underrepresented, source of secondary pollution in urban environments.