天津市环境空气中挥发性有机物的污染特征OA

We conducted our present study on the pollution characteristics of volatile organic compounds(VOCs)in ambient air in different functional areas of Tianjin,especially in industrial areas and central urban areas.In the study,between No-vember 2022 and May 2023,two stations in the industrial area(BH)and the central urban area(HX)were selected to quanti-tatively monitor 115 VOCs in ambient air in winter and spring,and analyze their concentration levels,pollution characteris-tics and photochemical reactivity.The results showed that during the observation period,the average concentrations of total VOCs at the BH and HX stations were(105.23±63.61)µg/m3 and(67.75±43.36)µg/m3,respectively,with the former 55.3%higher than the latter.Moreover,the VOCs at both stations in winter and spring were characterized by BH＞HX and the mass concentration of VOCs decreased to different degrees from winter to spring.The components with the highest proportions at BH and HX were alkanes and oxygenated VOCs(OVOCs),respectively,and the species with the highest proportions at BH was methylene chloride,while acetone was found at HX.Aromatic hydrocarbons were the highest con-tributors to the ozone formation potential(OFP)and secondary organic aerosol formation potential(SOAP)at both stations,with 36.4%and 91.5%,respectively,while cis-2-butene and toluene were the highest contributors to the OFP and SOAP,respectively.The characteristic species ratios indicate that the local VOCs air masses are highly aged and somewhat affected by long-distance transport.The results of this research can provide reference for differentiated pollution control.