Sources of non-methane hydrocarbons in surface air in Delhi, India.
Sources of non-methane hydrocarbons in surface air in Delhi, India.
复制标题
DOI：
10.1039/d0fd00087f
复制
发表时间：
2020-08
影响因子：
3.4
通讯作者：
G. Stewart;Beth S. Nelson;Will S. Drysdale;W. Acton;A. Vaughan;J. Hopkins;R. Dunmore;C. Hewitt;E. Nemitz;N. Mullinger;B. Langford;S. Shivani;Ernesto Reyes-villegas;R. Gadi;A. Rickard;James D. Lee;J. Hamilton
中科院分区：
文献类型：
--
作者：
G. Stewart;Beth S. Nelson;Will S. Drysdale;W. Acton;A. Vaughan;J. Hopkins;R. Dunmore;C. Hewitt;E. Nemitz;N. Mullinger;B. Langford;S. Shivani;Ernesto Reyes-villegas;R. Gadi;A. Rickard;James D. Lee;J. Hamilton
快速的经济增长和发展加剧了印度各地的空气质量问题，这是由于许多对污染源知之甚少，而了解它们的相对重要性对于描述空气污染的主要驱动因素仍然至关重要。对90种非甲烷碳氢化合物（NMHCs）（C2-C14）进行了全面的测量，包括12种物种单萜和更高分子量的单芳烃，是在雨季前的旧德里的一个城市遗址上制作的（2018年5月28日至6月5日）和后季风季节（2018年10月11日至27日）使用双通道气相色谱（DC-GC-FID）和二维气相色谱（GC×GC-FID）。显着更高的混合比NMHCs测量在后季风运动，平均夜间增强约6。与氮氧化物和一氧化碳一样，除异戊二烯外，所有NMHC均观察到强烈的昼夜分布，NMHC混合比在35-1485 ppbv之间。混合比的苯，甲苯，二甲苯和二甲苯（BTEX）的总和经常超过100 ppbv的夜间在后季风期间，与最大测量的混合比的单芳香族物质的370 ppbv。高活性单萜的混合比达到峰值约6 ppbv的后季风运动和相关性强，与人为NMHCs，这表明在德里的一个强大的非生物源。进行了详细的源解析研究，其中包括一氧化碳，乙炔和其他非甲烷碳氢化合物的回归分析，层次聚类分析，美国环保署EPAX6.0，主成分分析/绝对主成分得分（PCA/APCS）和比较与非甲烷碳氢化合物的比例（苯/甲苯和异/正戊烷）在环境样品的液体和固体燃料。这些分析表明，德里人为NMHC的主要来源是交通排放（汽油和柴油），Unmix和PCA/APCS模型的平均混合比例贡献为38%来自汽油，14%来自柴油，32%来自液化石油气（LPG），较小的贡献（16%）来自固体燃料燃烧。运动期间的基本气象的详细考虑表明，极端夜间混合比的NMHCs在后季风运动的结果排放到一个非常浅的和停滞的边界层。这项研究的结果表明，尽管在印度广泛的露天焚烧，交通相关的汽油和柴油排放仍然是德里气相城市空气污染的主要驱动因素。
Rapid economic growth and development have exacerbated air quality problems across India, driven by many poorly understood pollution sources and understanding their relative importance remains critical to characterising the key drivers of air pollution. A comprehensive suite of measurements of 90 non-methane hydrocarbons (NMHCs) (C2-C14), including 12 speciated monoterpenes and higher molecular weight monoaromatics, were made at an urban site in Old Delhi during the pre-monsoon (28-May to 05-Jun 2018) and post-monsoon (11 to 27-Oct 2018) seasons using dual-channel gas chromatography (DC-GC-FID) and two-dimensional gas chromatography (GC×GC-FID). Significantly higher mixing ratios of NMHCs were measured during the post-monsoon campaign, with a mean night-time enhancement of around 6. Like with NOx and CO, strong diurnal profiles were observed for all NMHCs, except isoprene, with very high NMHC mixing ratios between 35-1485 ppbv. The sum of mixing ratios of benzene, toluene, ethylbenzene and xylenes (BTEX) routinely exceeded 100 ppbv at night during the post-monsoon period, with a maximum measured mixing ratio of monoaromatic species of 370 ppbv. The mixing ratio of highly reactive monoterpenes peaked at around 6 ppbv in the post-monsoon campaign and correlated strongly with anthropogenic NMHCs, suggesting a strong non-biogenic source in Delhi. A detailed source apportionment study was conducted which included regression analysis to CO, acetylene and other NMHCs, hierarchical cluster analysis, EPA UNMIX 6.0, principal component analysis/absolute principal component scores (PCA/APCS) and comparison with NMHC ratios (benzene/toluene and i-/n-pentane) in ambient samples to liquid and solid fuels. These analyses suggested the primary source of anthropogenic NMHCs in Delhi was from traffic emissions (petrol and diesel), with average mixing ratio contributions from Unmix and PCA/APCS models of 38% from petrol, 14% from diesel and 32% from liquified petroleum gas (LPG) with a smaller contribution (16%) from solid fuel combustion. Detailed consideration of the underlying meteorology during the campaigns showed that the extreme night-time mixing ratios of NMHCs during the post-monsoon campaign were the result of emissions into a very shallow and stagnant boundary layer. The results of this study suggest that despite widespread open burning in India, traffic-related petrol and diesel emissions remain the key drivers of gas-phase urban air pollution in Delhi.