Researchers reveal the relationship between air oxidation and air pollution

In the atmospheric environment, pollutants emitted by human activities are oxidized and become secondary pollutants, which are gradually removed from the atmosphere. Therefore, understanding atmospheric oxidation is critical for air pollution control.

Currently, research on air pollution mainly focuses on analysis of concentration changes and mutual conversion of air pollutants, and there is relatively little research on the relationship between atmospheric oxidation and air pollution.

A research team led by Professor Gao Xiaoqing of the Northwest Institute of Ecology and Environmental Resources, Chinese Academy of Sciences, used empirical formulas to estimate and analyze the emission of primary pollutant particles and the formation of secondary pollutant particles in the atmosphere. Change characteristics of major atmospheric oxidants in Lanzhou City.

the study Published in Total environmental science.

The researchers investigated the possible causes of changes in pollution sources and concentrations in highly polluted weather and elucidated the mechanisms of atmospheric oxidation that influence the secondary formation of atmospheric particles.

The results show that atmospheric oxidation has a threshold effect on the secondary formation of atmospheric particles. When the concentration of oxidizing agent in the atmosphere is low (MDA8O)₃≤100μg/m3³), the oxidation process of volatile organic compounds in the atmosphere is easier to achieve, more secondary aerosols are generated, and the formation of secondary particles is promoted.

When the concentration of oxidizing agent in the atmosphere exceeds 160μg/m2³, the proportion of secondary particulate matter is lower than the proportion of primary particulate matter. Total oxidant Ox (O_X=O₃+No₂) is negatively correlated with the sulfur oxidation rate and nitrogen oxidation rate, indicating that the SO production rate decreases.₂ and no₂ inhibited by high concentrations of O_X.

The anticyclone ridge over Lanzhou was maintained for a long time, which reduced the surface wind speed and weakened the transport and dispersion of pollutants near the surface.prime minister_2.5 The atmosphere in Lanzhou is mainly from the Hexi Corridor area, and the prime minister_Ten Mainly from southeastern Lanzhou.

This study deepens the understanding of atmospheric oxidation that affects the formation mechanism of air pollution, and provides reference materials for air pollution prevention and control and air quality improvement in Lanzhou City.