The team of Professor CHEN Qingcai of SUST has made progress in the field of atmospheric photochemistry

Author: CHEN Qingcai

Release: LI Guangming

Translator: HOU Yumo

Recently, Professor CHEN Qingcai' s team from the College of Environmental Science and Engineering has published relative research results in the top journal "Atmospheric Chemistry and Physics" (impact factor: 6.133) with the title "Photo-degradation of atmospheric chromophores: type conversion and changes in photochemical reactivity. Professor CHEN Qingcai is the only corresponding author, master student MU Zhen is the first author, and Shaanxi University of Science and Technology is the first unit and the only communication unit.

Based on the uncertain environmental factors in the control of air pollution in Guanzhong area in China, the study has explored the characteristics and mechanism of the photochemical reaction of atmospheric PM2.5 in Xi'an, and assessed the potential impact of atmospheric photochemical reactions on regional air quality and climate. The photochemical reaction process of atmospheric PM2.5 in Xi'an has been simulated by experiments: (1) It has been found that photochemical action can weaken the ability of PM2.5 absorbing sunlight energy, and thereby weaken the contribution of PM2.5 to the regional greenhouse effect; (2) It has proved that the effect of sunlight on the change of the chemical composition of PM2.5, and has been found that triplet substances are important active intermediates in photochemical reactions, which can generate free radicals to promote the aging of PM2.5; (3) PM2.5 from different sources has different chemical sensitivity to sunlight, and sunlight can cause changes in the photochemical reactivity of PM2.5, which in turn changes the lifetime of PM2.5 in the atmosphere and air quality.

The effect of sunlight on the chemical composition and photochemical reaction ability of atmospheric PM2.5

The effect of PM2.5 triplet on the generation of singlet oxygen and the effect of sunlight on the production of singlet oxygen

The research results have provided an important theoretical basis for the uncertain environmental factors and impact mechanism in control of air pollution in the Guanzhong area in China, and explained the incomplete matching between"pollution source reduction" and“haze reduction" from the perspective of the effect of sunlight on PM2.5 concentration, chemical composition and atmospheric lifetime. The research on this subject lasted for two years and was supported by the National Natural Science Foundation of China (41703102, 41877354).

Achievement details:

Zhen Mu, Qingcai Chen*, Lixin Zhang, et al. Photo-degradation of atmospheric chromophores: type conversion and changes in photochemical reactivity. Atmospheric Chemistry and Physics 2021, doi: 10.5194/acp-2020-1223.