Space and Atmospheric Science Division, Physical Research Laboratory, Ahmedabad, India; Department of Environmental Science and Engineering, Fudan University, Shanghai, China.
Space and Atmospheric Science Division, Physical Research Laboratory, Ahmedabad, India.
Environ Pollut. 2019 Sep;252(Pt A):245-255. doi: 10.1016/j.envpol.2019.05.089. Epub 2019 May 18.
This is the first study to characterize the variation and emission of C-C non-methane volatile organic compounds (NMVOCs) in a semi-urban site of western India based on measurements during February-December 2015. Anthropogenic NMVOCs show clear seasonal dependence with highest in winter and lowest in monsoon season. Biogenic NMVOCs likes isoprene show highest mixing ratios in the pre-monsoon season. The diurnal variation of NMVOC species can be described by elevated values from night till morning and lower values in the afternoon hours. The elevated levels of NMVOCs during night and early morning hours were caused mainly by weaker winds, temperature inversion and reduced chemical loss. The correlations between NMVOCs, CO and NOx indicate the dominant role of various local emission sources. Use and leakage of liquefied petroleum gas (LPG) contributed to the elevated levels of propane and butanes. Mixing ratios of ethylene, propylene, CO, NOx, etc. show predominant emissions from combustion of fuels in automobiles and industries. The Positive Matrix Factorization (PMF) source apportionments were performed for the seven major emission sectors (i.e. Vehicular exhaust, Mixed industrial emissions, Biomass/Fired brick kilns/Bio-fuel, Petrochem, LPG, Gas evaporation, Biogenic). Emissions from vehicle exhaust and industry-related sources contributed to about 19% and 40% of the NMVOCs, respectively. And the rest (41%) was attributed to the emissions from biogenic sources, LPG, gasoline evaporation and biomass burning. Diurnal and seasonal variations of NMVOCs were controlled by local emissions, meteorology, OH concentrations, long-range transport and planetary boundary layer height. This study provides a good reference for framing environmental policies to improve the air quality in western region of India.
这是首次在印度西部一个半城市地区基于 2015 年 2 月至 12 月的测量结果，对 C-C 非甲烷挥发性有机化合物 (NMVOC) 的变化和排放进行特征描述的研究。人为 NMVOC 表现出明显的季节性依赖关系，冬季最高，季风季节最低。生物源 NMVOC 如异戊二烯在季风前季节表现出最高的混合比。NMVOC 物种的日变化可以描述为从夜间到清晨升高，下午降低。夜间和清晨 NMVOC 水平升高主要是由于风较弱、温度逆温和化学损失减少。NMVOC 与 CO 和 NOx 的相关性表明各种当地排放源的主导作用。液化石油气 (LPG) 的使用和泄漏导致丙烷和丁烷水平升高。乙烯、丙烯、CO、NOx 等的混合比表明主要来自汽车和工业燃料燃烧的排放。对 7 个主要排放源（即车辆尾气、混合工业排放、生物质/烧制砖窑/生物燃料、石化、LPG、气体蒸发、生物源）进行了正矩阵因子分析 (PMF) 源分配。车辆尾气和工业相关来源的排放分别占 NMVOCs 的 19%和 40%左右。其余（41%）归因于生物源、LPG、汽油蒸发和生物质燃烧的排放。NMVOC 的日变化和季节变化受当地排放、气象、OH 浓度、长程传输和行星边界层高度的控制。本研究为制定环境政策以改善印度西部地区的空气质量提供了良好的参考。
