Chinanews client, Beijing, November 3 (Reporter Zhang Ni) According to data, in 2019, the ozone concentration in 337 cities above the prefecture level increased by 6.5% year-on-year. The number of days exceeding the standard with ozone as the primary pollutant accounted for the total number of days exceeding the standard. 41.8%.
The impact of ozone on the number of days with good air quality is second only to PM2.5. Experts say that the treatment of volatile organic compounds (VOCs), which are closely related to ozone pollution, is imminent.
Data map: Waste gas collection device of a company.
Suihuan Announcement
How serious is ozone pollution?
On the 3rd, the eighth environmental tea party of "Developing Supervision and Assistance to Reduce VOCs Emissions" sponsored by the Publicity and Education Center of the Ministry of Ecology and Environment and China Environmental Records Association was held in Beijing.
Li Tianwei, Inspector of the Ecological Enforcement Bureau of the Ministry of Ecology and Environment, said at the meeting that in 2019, the ozone concentration in 337 cities above the prefecture level increased by 6.5% year-on-year, and the number of days exceeding the standard with ozone as the primary pollutant accounted for 41.8% of the total number of days exceeding the standard. This resulted in a loss of 2.3% year-on-year in the ratio of good days in the country.
Especially in the Beijing-Tianjin-Hebei and surrounding areas, and the Yangtze River Delta, the proportion of days with ozone as the primary pollutant exceeded PM2.5.
"The increase in ozone concentration has gradually become an important factor influencing the number of days after PM2.5." Li Tianwei said.
What exactly is ozone pollution?
How is it formed?
In fact, in the stratosphere of the atmosphere, ultraviolet radiation will break the chemical bond between the two oxygen atoms of the oxygen molecule. Because the oxygen atom is extremely unstable, the remaining oxygen atom will combine with another oxygen molecule to form Ozone-a complete "natural" product.
In the troposphere, except for some ozone that "roams" from the stratosphere to the troposphere and the ozone contributed by forest vegetation organisms, most of the ozone is "artificial secondary conversion products", such as nitrogen oxides NOx, VOCs, etc. It is a secondary pollutant produced by complex photochemical reactions.
The maximum 8-hour average value of ozone concentration on that day exceeds 160 micrograms per cubic meter, which means ozone pollution.
Ma Jun, director of the Beijing Public and Environmental Research Center, introduced at the meeting that volatile organic compounds and nitrogen oxides work together to form ozone, which is also one of the precursors of PM2.5 formation and is currently an important source of air pollutants in China. Atmospheric environmental quality and human health have an important impact.
VOCs emissions mainly appear in the production process of raw and auxiliary materials or products of enterprises, most of which are flammable and explosive, and some are toxic and hazardous substances.
"VOCs pollution control started much later than sulfur dioxide, nitrogen oxides, PM10 and PM2.5 particulate matter. At present, VOCs emissions are still very large, and they must be treated as soon as possible in tandem with nitrogen oxides to curb the frequent occurrence of ozone." Ma Jun emphasized .
Data map: Comprehensive monitoring vehicle for atmospheric movement.
Photo by Li Haihui
Expert: Keep an eye on key areas and control objects
In recent years, the governance of VOCs has been highly valued by the state.
Earlier, the Ministry of Ecology and Environment issued the "2020 Volatile Organic Compounds Governance Tackling Plan."
In addition, the Ministry of Ecology and Environment has also organized a summer ozone pollution attack in key areas and 95 cities at the junction of Jiangsu, Anhui, Shandong and Henan.
In mid-July this year, supervision and assistance were launched. 624 working groups of 2,039 people have been sent to 79 cities with heavy ozone pollution to inspect 67,000 enterprises and help localities find 19,000 enterprises involved in VOCs environmental problems 65,000.
Data show that in July this year, ozone concentrations in key areas such as Beijing, Tianjin, Hebei, Shanxi, Shanghai, Jiangsu, Zhejiang, Anhui, Shandong, Henan, and Shaanxi have significantly reduced, and the number of days of ozone exceeding the standard has been significantly reduced, and no obvious, large-scale regionality Ozone pollution process.
"The work also exposed problems such as weak supervision and management foundation and insufficient capacity at the grassroots level." Li Tianwei emphasized at the meeting.
He analyzed that at present, no accurate and practical list of VOCs corporate pollution sources has been established in various places; the third-party detection market is chaotic and lacks supervision; law enforcement capabilities are insufficient, and many places have low equipment such as navigation vehicles and infrared cameras, and they are not used professionally. Staff and idle.
He also suggested that the role of economic policy tools should be fully utilized, such as improving tax price policies, including VOCs as a whole into the scope of environmental protection tax collection, implementing differentiated taxation policies, exclusive taxation, and expanding the scope of consumption tax collection for products containing VOCs.
In addition, fiscal funds should be strengthened to support governance, and local governments should use special funds and expand green credit to support corporate pollution prevention and control work.
Ma Jun emphasized that as the top priority in the field of waste gas treatment in China in the future, it is necessary to summarize the experience in the previous treatment, improve the treatment technology route, improve the equipment level and treatment effect, focus on key areas and key control objects, and comprehensively strengthen the photochemical reaction. Control of VOCs with strong activity.
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