[Characteristics of VOCs Pollution in the Winter Atmosphere of a Typical Petrochemical Industry Park].

Concentrations of volatile organic compounds (VOCs) in ambient air of a typical petrochemical industry park were measured using an on-line monitor (TH-300B) from December 2014 to February 2015. The composition, temporal variations, sources, and photochemical reactivity of VOCs were analyzed. Alkanes were the most abundant VOC species and contributed to 86.73% to total VOC concentrations in winter. Concentrations of TVOCs, alkanes, alkenes, and aromatic hydrocarbons were high at night and low during the day. The changes in alkane and alkene concentrations were consistent with those in TVOC concentrations. Using principal component analysis and multiple linear regression (PCA-MLR) in combination, five sources of VOCs were identified; fuel evaporation, industrial emissions, a mix of gasoline vehicle exhaust and plant emissions, diesel vehicle exhaust emissions, and fuel combustion with contributions of 60.02%, 8.50%, 2.07%, 12.21%, and 17.20%, respectively. Propylene-equivalent concentration (Propy-Equiv) and maximum incremental reactivity (MIR) method were used to calculate the contributions of VOCs measured in the study area to ozone production. Alkanes contributed most to ozone production followed by alkenes and aromatic hydrocarbons. The contribution rate of cyclopentane, n-butane, and 1-pentene were higher owing to their long photochemical age in the study area.