[Characteristics and Source Apportionment of Ambient Volatile Organic Compounds in Shijiazhuang High-tech Industrial Development Zone in Autumn].

Utilizing the online monitoring data of volatile organic compounds （VOCs） and ozone （O ₃ ） in the Shijiazhuang high-tech industrial development zone during October 2020, the pollution characteristics of VOCs were analyzed. Subsequently, ·OH estimation, secondary organic aerosol formation potential （SOAP）, and ozone formation potential （OFP） were applied to assess the chemical reactivity of VOCs. Additionally, the source apportionment was identified using the positive matrix factorization （PMF） model. The results revealed that the hourly φ [total VOCs （TVOCs）] were （11-281）×10 ^-9 , and the components were ranked by volume fraction in the following order： oxygenated volatile organic compounds （OVOCs） （60.83%）, alkanes （19.98%）, halohydrocarbons （5.64%）, aromatics （5.91%）, alkenes （4.83%）, and alkynes （2.48%）. Although the VOC concentration levels posed negligible non-carcinogenic risks to human health, benzene and ethylbenzene presented carcinogenic risks. The m / p -xylene to ethylbenzene ratio （X/E） varied from 2.5 to 3.4, indicating short-range transport of fresh air masses. Based on the X/E value, the ·OH concentration was 1.75×10 ⁶ molecule·cm ^-3 , and the ·OH exposure from 07：00 to 14：00 was calculated as 3.77×10 ¹⁰ molecule·s·cm ^-3 . Aromatics played a dominant role in SOA, with a contribution rate as high as 93.35%, while alkenes dominated O ₃ formation, with the OFP contribution rate reaching up to 46.79%. By applying the PMF model, five major VOC sources were identified, including industrial sources （37.20%）, process flow and solvent use （33.80%）, vehicle and oil/gas evaporation sources （15.47%）, combustion sources （8.03%）, and plant emissions （5.50%）. Industrial and process emissions emerged as the primary contributors to VOCs in the ambient air of the high-tech zone, necessitating targeted control measures within this region.