Abstract
Hebei is one of the most air-polluted provinces located in China. In this study, NOx, volatile organic compounds (VOCs), and ozone (O3) observational data obtained at 7 monitoring sites in Hebei Province in the warm season (May to September) in 2019 were analyzed to investigate the spatiotemporal distribution, composition characteristics, and chemical reactivity of VOCs. Results indicated that VOCs concentrations were the highest in Shijiazhuang and Langfang (47.8 and 39.2 ppb, respectively) and the lowest in Zhangjiakou and Chengde (16.6 and 12.0 ppb, respectively). In the warm season in 2019, the monthly average concentrations of VOCs increased initially and decreased subsequently, and the highest concentration found in July and August. The diurnal variation patterns of VOCs exhibited a double-peak curve, with the first peak occurring between 07:00–09:00, influenced by the production and life activities of residents. The second peak occurred between 23:00–0:00 due to the poor atmospheric diffusion conditions at nighttime and the possible transportation from residual layer. Alkanes, haloalkanes, and alkenes were responsible for the largest components to VOCs in Hebei Province, with the average proportions at the 7 monitoring sites of 43.25%, 30.39% and 15.00%, respectively. The ratios of toluene to benzene (T/B) of the monitored sites indicated that the VOCs concentrations at the Shijiazhuang and Xingtai sites were mainly influenced by emissions from coal combustion. In comparison, the VOCs concentrations at the Baoding and Langfang sites were mainly influenced by motor vehicle emissions, while the sites at Zhangjiakou and Chengde were mainly influenced by solvent-based coating and industrial process emissions. Alkenes had the highest chemical reactivity of the VOCs in Hebei Province, ethylene, propene, toluene, and 1-butene were also the high chemical reactivity species. Lastly, tailored schemes for the reduction of O3 precursor were proposed based on the NOx, VOCs, and O3 data obtained from the various monitoring sites.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
