A measurement and modelling investigation of the indoor air chemistry following cooking activities.
A measurement and modelling investigation of the indoor air chemistry following cooking activities.
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烹饪活动后室内空气化学的测量和建模研究。
DOI：
10.1039/d3em00167a
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发表时间：
2023
期刊：
影响因子：
--
通讯作者：
Davies HL
中科院分区：
文献类型：
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作者：
Davies HL
家庭烹饪是室内空气污染物的来源之一，包括挥发性有机化合物(VOCs)，这可能会影响室内空气质量。然而，烹饪产生的VOC的实时排放没有得到很好的描述，同样，人们对由此产生的二次化学也知之甚少。本文采用选择离子流动管质谱(SIFT-MS)技术，在室温、半真实的环境中，对鸡肉蔬菜炒饭烹调过程中挥发性有机化合物的排放进行实时监测。挥发性有机化合物的排放主要是醇(占总排放量的70%)，但也含有一系列的醛(14%)和萜烯(5%)，这主要是由于油的加热和香料的制备和加热。然后，使用室内化学模型(INCHEM-Py)模拟了与烹饪相关的直接VOC排放，以研究由此产生的二次化学。模型显示，VOC浓度主要由直接排放决定，次生产物的贡献很小，尽管次生物种的寿命比直接排放的物种更长。烹调后，羟基自由基浓度降低了86%，而有机过氧自由基水平增加了700%以上，后来形成了次生有机硝酸盐、过氧酰硝酸酯(PAN)和甲醛。单萜烯的排放被证明推动了二次甲醛的形成，尽管产生的浓度相对较小(平均为60ppt)。对模拟条件的敏感性分析表明，增加室外臭氧和NOx的浓度(分别为2.9倍和9倍)会导致室内二次产物生成的最大增加(有机硝酸盐、PAN和甲醛的≈分别增加400%、200%和600%)。鉴于气候变化可能导致未来臭氧浓度增加，以及随着气温上升而增加窗户打开的可能性，未来家庭可能会有更高浓度的室内氧化剂。因此，这项研究表明，烹饪可能是未来室内二次污染物的一个更重要的来源。
Domestic cooking is a source of indoor air pollutants, including volatile organic compounds (VOCs), which can impact on indoor air quality. However, the real-time VOC emissions from cooking are not well characterised, and similarly, the resulting secondary chemistry is poorly understood. Here, selected-ion flow-tube mass spectrometry (SIFT-MS) was used to monitor the real-time VOC emissions during the cooking of a scripted chicken and vegetable stir-fry meal, in a room scale, semi-realistic environment. The VOC emissions were dominated by alcohols (70% of total emission), but also contained a range of aldehydes (14%) and terpenes (5%), largely attributable to the heating of oil and the preparation and heating of spices, respectively. The direct cooking-related VOC emissions were then simulated using the Indoor Chemical Model in Python (INCHEM-Py), to investigate the resulting secondary chemistry. Modelling revealed that VOC concentrations were dominated by direct emissions, with only a small contribution from secondary products, though the secondary species were longer lived than the directly emitted species. Following cooking, hydroxyl radical concentrations reduced by 86%, while organic peroxy radical levels increased by over 700%, later forming secondary organic nitrates, peroxyacylnitrates (PANs) and formaldehyde. Monoterpene emissions were shown to drive the formation of secondary formaldehyde, albeit to produce relatively modest concentrations (average of 60 ppt). Sensitivity analysis of the simulation conditions revealed that increasing the outdoor concentrations of ozone and NOx species (2.9× and 9×, respectively) resulted in the greatest increase in secondary product formation indoors (≈400%, 200% and 600% increase in organic nitrates, PANs and formaldehyde production, respectively). Given the fact that climate change is likely to result in increased ozone concentrations in the future, and that increased window-opening in response to rising temperatures is also likely, higher concentrations of indoor oxidants are likely in homes in the future. This work, therefore, suggests that cooking could be a more important source of secondary pollutants indoors in the future.