Characteristics and Source Approtionment of VOCs during the Autumn and Winter in Liaocheng
To better understand the pollution characteristics and sources of volatile organic compounds(VOCs),and their po-tentials for the formation of O3 and secondary organic aerosol,the volume concentrations of 115 VOCs during the autumn and winter in the urban atmosphere of Liaocheng were monitored by online monitoring system.In this study,the ozone formation potential(OFPs)and SOA formation potential(SOAFPs)were determined using the maximum incremental reactivity coeffi-cient and the fractional aerosol coefficient,respectively.In addition,the sources of VOCs were analyzed using the characteris-tic ratios and positive matrix factorization(PMF).The results showed that the chemical compositions VOCs were similar in autumn and winter.Alkanes and OVOCs were the two most abundant species.The OFPs in winter was 140.2×10-9,which was about 1.6 times higher than that(89.0×10-9)in autumn.OVOCs and C2～C4 olefins contributed the most to the OFPs of VOCs(54.7％～58.6％)in autumn and winter.The concentration level of SOAFPs in autumn(1.0 µg/m3)was similar to that(1.2 μg/m3)in winter.M/p-xylene,toluene,and o-xylene contributed the most to SOAFPs in both autumn and winter.The ra-tio of toluene to benzene(T/B)indicated the motor vehicle exhaust was one of the important sources in Liaocheng.The results of PMF showed that the biogenic sources and secondary formation,vehicle exhaust emissions,fuel combustion sources,sol-vent usage sources,and industrial sources were the dominant sources of VOCs in autumn,which accounted for 27.2％,19.5％,18.5％,17.5％and 17.3％,respectively.Nevertheless,the gasoline vehicles exhausts,organic chemical industry emissions,in-dustrial halocarbon emissions,diesel vehicle exhausts,and solvent usage sources were the main sources of VOCs in winter,which accounted for 24.4％,21.3％,20.8％,16.9％and 16.6％,respectively.The results can provide important data for the con-trol of VOCs and improvement of air quality in Liaocheng City.
万方数据
维普
