典型汽修企业 VOCs 排放特征及对臭氧污染影响研究

The automotive repair industry，especially the painting process，is a significant contributor to the emission of Volatile Organic Compounds （VOCs）. These enterprises are numerous，widely distributed，and emit VOCs intermittently. Auto repair enterprises can be categorized into first and second-class whole vehicle repair enterprises and third-class general small repair and specialized repair businesses. This study focused on 12 auto repair enterprises in Sanyuan County to investigate the characteristics of VOC emissions in the auto repair processes and calculate their Ozone Formation Potential（OFP）. The results indicate that the VOC emission concentration from second-class auto repair enterprises（（75111±5761）×10^-9）was higher than that of first-class（（31959.5±4738）×10^-9）and third-class enterprises（（24334.2±3278）×10^-9）. It is crucial to prioritize the reduction of VOC emissions from second-class auto repair companies. In terms of component characteristics，the main VOCs emitted by the auto repair industry are Oxygenated VOCs （OVOCs，41.2%±7.3%），followed by aromatics （25.3%±1.1%）；the trend of OFP was similar pattern as the VOC concentration：second-class auto repair enterprises（359.5 mg . m^-3）> first-class（251.7 mg . m^-3）> third-class（188.8 mg . m^-3），with aromatic hydrocarbons contributing the most to OFP（61.3%±6.4%），followed by alkenes（28.7%±6.1%）. Reducing VOC emissions from auto repair processes is of significant importance in controlling ozone generation. Regarding repair processes，both puttying（（30794±678）×10^-9）and painting（（72512± 426）×10^-9）result in a substantial amount of VOC emissions，which are major sources of VOC emissions from auto repairs companies，primarily consisting of OVOCs（46.2%±1.1%），followed by aromatics（24.5%±2.9%）. Different auto repair materials exhibit distinct source profiles，with VOC emissions mainly comprising OVOCs（39.3%~73.5%），followed by aromatics（19.1%~21.4%），while lower concentrations of alkanes，alkenes，and halogenated hydrocarbons were observed，each accounting for less than 10%. The source profiles of auto repair raw materials can serve as the basis for accurate source apportionment，and studying VOC emissions from different scales auto repair enterprises can provide a scientific foundation for formulation VOC emissions reduction policies for auto repair enterprises in Sanyuan County.