Characteristics, Source Analysis And Environmental Effects Of Atmospheric Volatile Organic Compounds In Nanjing Industrial Zone

The"14th Five-Year Plan"puts forward new requirements for the prevention and control of air pollution.VOCs,as important precursors of atmospheric O3,have received more and more attention.Continuous observation of atmospheric VOCs in Nanjing Industrial Zone to understand the pollution characteristics and sources.The maximum incremental reaction activity coefficient(MIR)was used to estimate the O₃ generation potential.The formation aerosol coefficient(FAC)and the SOAP factor method were used to estimate the SOA generation potential.The concentration of TVOCs and their components were high in autumn and winter and low in spring and summer.The composition of VOCs was affected by both meteorological and traffic emissions,and presents a"bimodal"diurnal variation characteristic.The concentration of VOCs compounds at night was higher than during the day.Weather conditions with high humidity and low wind speed were more conducive to accumulate of pollutants.Isoprene had the highest concentration in summer and the lowest in winter.It has a"single-peak"diurnal variation in summer,which is significantly affected by plant emissions.It had a"double-peak"variation in winter,which is significantly affected by traffic emissions.Judging by the ratio of X/E,it was found that atmospheric VOCs are greatly affected by regional transmission.Preliminary judgments using the ratio of T/B found that the summer,autumn and winter were more affected by traffic emissions,and the spring was affected by the combined effects of mixed sources.Preliminary judgment using the ratio of i/n found that the summer may be more affected by fuel evaporation,and the winter may be more affected by traffic emissions.The PMF model was used to determine the emission sources in spring,summer and autumn as:biological sources,vehicle exhaust sources,industrial sources,paint solvent sources,fuel volatilization sources,and no biological sources in winter.Traffic and industrial emissions were the most important sources of VOCs.Isoprene mainly came from biological emissions in spring,summer and autumn,and from traffic emissions in winter.Aromatic hydrocarbons and olefins contributed the most to OFP,and benzene series,ethylene and OVOCs were the dominant species that generate atmospheric O₃.Using the FAC coefficient method and SOAP factor method,it was found that aromatic hydrocarbons are the key species that generate atmospheric SOA.In the future,Nanjing's treatment of atmospheric SOA pollution should focus on factory emissions and paint solvent emissions.