The sources of volatile organic compounds in the summer atmosphere and the contribution to ozone generation in Changzhi, a typical industrial city

In this study, taking Changzhi as a typical industrial city, the source apportionment of Volatile Organic Compounds (VOCs) was carried out used positive definite matrix factorization (PMF) model, and the atmospheric photochemical reaction process and O3 formation sensitivity were analyzed based on an observation-based model (AtChem-MCM). The results showed that the concentrations of alkanes, alkenes, alkynes and aromatics accounted for 57.49%, 16.05%, 9.17% and 17.29% of TVOC in Changzhi, respectively. PMF results showed that vehicle emission was the major source of VOCs (28.45%), followed by industrial process (26.19%), combustion sources (21.09%), biogenic sources (12.99%) and solvent utilization (11.28%). The simulation results of O3 formation showed that the average net formation rate of O3 during daytime was 23.01×10-9h-1, which reached a peak value (54.32 ×10-9h-1) at 11o'clock. The formation of O3 in Changzhi was sensitive to both VOCs and NOx, and alkene (1.05) and NOx (0.35) had the higher relative incremental reaction activity coefficients (RIR). Industrial process (0.072), solvent utilization (0.071) and vehicle emissions (0.068) had the higher RIR value, which were the key sources contributed to O3 formation. Therefore, industrial process and vehicles emissions should be strengthen for the control of O3 in industrial cities. © 2024 Chinese Society for Environmental Sciences. All rights reserved.