[Haichuan Environmental News] Nitrate and vehicle emissions have become the most significant components and primary sources of PM2.5 at present.
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According to the Science and Technology Daily, the Beijing-Tianjin-Hebei region and its surrounding areas are experiencing a severe air pollution episode. By February 27, 30 cities had activated their early warning systems, with 15 of them issuing orange warnings; Beijing issued a yellow warning. Hao Jiming, an academician of the Chinese Academy of Engineering and professor at Tsinghua University, said that from the night of the 28th to the early hours of March 1st, affected by cold air, the air quality in the central Beijing-Tianjin-Hebei urban cluster, including Beijing and Tianjin, is expected to improve. Liu Bingjiang, director of the Department of Atmospheric Environment Management at the Ministry of Environmental Protection, said that studies have shown that the primary pollutants and sources of pollution in different cities are \"significantly different\". In Beijing, nitrates and vehicle emissions have become the most important components and primary sources of PM2.5 at present.
The focus of governance has shifted from coal to diesel vehicles. An analysis of pollutant characteristics shows that during this pollution episode, carbon monoxide levels in Beijing were relatively high； Sulfate components account for about 20% of the total mass of PM2.5, and the chloride ion concentration also shows a similar upward trend. **Professor He Kebin, deputy director of the Joint Center for Air Pollution Control and an academician of the Chinese Academy of Engineering, explained that research findings from projects aimed at understanding the causes of severe air pollution and developing solutions show that the main chemical components of PM2.5 pollution in the Beijing-Tianjin-Hebei region had changed by 2017. “In the ‘2+26 cities’, in the past, when severe pollution occurred, sulfates usually accounted for the largest proportion in secondary formation. Judging from the conditions during recent winters, nitrates have replaced sulfates as the most important and predominant component in the secondary formation of severe pollution during autumn and winter. Sulfates are a characteristic component of emissions from coal combustion, indicating that significant progress has been made in controlling coal use. Nitrates are formed from nitrogen oxides and other substances, and their main source is vehicle emissions. ” Liu Bingjiang also said that Beijing’s coal consumption has dropped from 20 million tons to 5 million tons, with emissions shifting from being primarily generated by the coal industry to those resulting from domestic activities. “Multiple **level teams conducted research on the causes of air pollution in Beijing and reached a common conclusion: vehicle emissions are the primary source of PM2.5 in Beijing at present. Therefore, Beijing has made the control of motor vehicle pollution a key focus for this year’s work, as a targeted approach to addressing air pollution. ” “Vehicles are a key focus for emission reduction in Beijing, especially those powered by diesel engines, including diesel trucks as well as non-road vehicles such as cranes and excavators. ”He Kebin said.
Can chemical industry workers breathe a sigh of relief?