In China, volatile organic compound（VOC） control directives have been continuously released and implemented for important sources and regions to tackle air pollution. The corresponding control requirements were base...In China, volatile organic compound（VOC） control directives have been continuously released and implemented for important sources and regions to tackle air pollution. The corresponding control requirements were based on VOC emission amounts（EA）, but never considered the significant differentiation of VOC species in terms of atmospheric chemical reactivity. This will adversely influence the effect of VOC reduction on air quality improvement. Therefore,this study attempted to develop a comprehensive classification method for typical VOC sources in the Beijing–Tianjin–Hebei region（BTH）, by combining the VOC emission amounts with the chemical reactivities of VOC species. Firstly, we obtained the VOC chemical profiles by measuring 5 key sources in the BTH region and referencing another 10 key sources, and estimated the ozone formation potential（OFP） per ton VOC emission for these sources by using the maximum incremental reactivity（MIR） index as the characteristic of source reactivity（SR）. Then, we applied the data normalization method to respectively convert EA and SR to normalized EA（NEA） and normalized SR（NSR） for various sources in the BTH region.Finally, the control index（CI） was calculated, and these sources were further classified into four grades based on the normalized CI（NCI）. The study results showed that in the BTH region,furniture coating, automobile coating, and road vehicles are characterized by high NCI and need to be given more attention; however, the petro-chemical industry, which was designated as an important control source by air quality managers, has a lower NCI.展开更多
Volatile organic compounds （VOCs） play ,an important role in ozone and secondary organic aerosol （SOA） formation, but VOCs sources during winter are not fully understood. To investigate VOCs sources during winter,...Volatile organic compounds （VOCs） play ,an important role in ozone and secondary organic aerosol （SOA） formation, but VOCs sources during winter are not fully understood. To investigate VOCs sources during winter, mixing ratios of C2-C12 VOCs were measured at an urban site in Beijing from December 29, 2011 to January 17, 2012. Correlation analysis of toluene to benzene and i-pentane to n-pentane suggest that coal combustion could also be an important source for VOCs besides vehicular emissions. Source apportionment results show that coal combustion and vehicular emissions contributed 28%-39% and 31%-45% to ambient VOCs during winter, respectively. Backward trajectory analyses demonstrated that contributions from the burning of coal were higher when air masses came from southern regions outside Beijing. Close attention should be paid to VOCs emissions from coal combustion in Beijing city and the vicinity to the South.展开更多
基金supported by the National Key Technology Support Program of China(Nos.2014BAC23B05&2014BAC23B02)the Natural Sciences Foundation of China(No.51478017)+1 种基金the Youth Individual Project of Beijing Talents Training Fund(No.2015000021733G170)the Ministry of Environmental Protection Special Funds for Scientific Research on Public Causes(No.201409016)
文摘In China, volatile organic compound（VOC） control directives have been continuously released and implemented for important sources and regions to tackle air pollution. The corresponding control requirements were based on VOC emission amounts（EA）, but never considered the significant differentiation of VOC species in terms of atmospheric chemical reactivity. This will adversely influence the effect of VOC reduction on air quality improvement. Therefore,this study attempted to develop a comprehensive classification method for typical VOC sources in the Beijing–Tianjin–Hebei region（BTH）, by combining the VOC emission amounts with the chemical reactivities of VOC species. Firstly, we obtained the VOC chemical profiles by measuring 5 key sources in the BTH region and referencing another 10 key sources, and estimated the ozone formation potential（OFP） per ton VOC emission for these sources by using the maximum incremental reactivity（MIR） index as the characteristic of source reactivity（SR）. Then, we applied the data normalization method to respectively convert EA and SR to normalized EA（NEA） and normalized SR（NSR） for various sources in the BTH region.Finally, the control index（CI） was calculated, and these sources were further classified into four grades based on the normalized CI（NCI）. The study results showed that in the BTH region,furniture coating, automobile coating, and road vehicles are characterized by high NCI and need to be given more attention; however, the petro-chemical industry, which was designated as an important control source by air quality managers, has a lower NCI.
基金funded by the Natural Science Foundation for Outstanding Young Scholars(No.41125018)
文摘Volatile organic compounds （VOCs） play ,an important role in ozone and secondary organic aerosol （SOA） formation, but VOCs sources during winter are not fully understood. To investigate VOCs sources during winter, mixing ratios of C2-C12 VOCs were measured at an urban site in Beijing from December 29, 2011 to January 17, 2012. Correlation analysis of toluene to benzene and i-pentane to n-pentane suggest that coal combustion could also be an important source for VOCs besides vehicular emissions. Source apportionment results show that coal combustion and vehicular emissions contributed 28%-39% and 31%-45% to ambient VOCs during winter, respectively. Backward trajectory analyses demonstrated that contributions from the burning of coal were higher when air masses came from southern regions outside Beijing. Close attention should be paid to VOCs emissions from coal combustion in Beijing city and the vicinity to the South.
