The Change Trend And Source Analysis Of Atmospheric VOCs In The Main Urban Area Of ??Harbin

Volatile organic compounds?VOCs?occupy an important position in the atmospheric environment and are important precursors for the formation of Secondary organic aerosol?SOA?and Ozone?O₃?.The contribution to atmospheric pollution is particularly obvious,and some VOCs can have a huge impact on human health and survival.Harbin is the northern city with the highest latitude and lowest temperature in China,which is the political,economic,cultural,transportation hub and important manufacturing base of the northeast.Its seasonal characteristics are long and cold in winter,short in summer,and rapid changes in spring and autumn.Therefore,it is of great significance and practical value to analyze the pollution characteristics and its trend with seasonal changes of atmospheric VOCs in Harbin.This paper collects 56 consecutive monitoring VOCs data from the atmosphere of Harbin Environmental Monitoring Center from June 2017 to May 2018 and November2018,and studies the pollution characteristics and pollution level of atmospheric volatile organic compounds?VOCs?in Harbin.Use PMF model to analyze the source of volatile organic compounds?VOCs?in Harbin,and study the sources of VOCs and put forward countermeasures against the pollution of atmospheric volatile organic compounds VOCs in Harbin.MeteoInfo backward trajectory clustering analysis model was used to process meteorological data,and the source and trajectory of atmospheric VOCs pollutants carried by Harbin air mass were obtained.Calculate the ozone?O₃?potential generation and secondary aerosol?SOA?potential generation of atmospheric volatile organic compounds?VOCs?,the priority control of VOCs pollutants was obtained.?1?During the monitoring period,the average concentration of TVOCs in the whole year is alkane>aromatic hydrocarbon>olefin>alkyne;the seasonal variation trend of TVOCs concentration is autumn>Winter>summer>spring,the concentration of TVOCs is higher in autumn,and overall concentration of TVOCs is relatively small;,the alkane component accounts for about 50%-60%of TVOC in the percentage of TVOCs in the four seasons;the olefins account for a relatively high proportion in autumn and winter.?2?In the daily variation of TVOCs of whole year,the concentration of TVOCs is higher throughout the day from 21:00 to 6:00,and reaches the highest value at 6 o'clock;the highest concentration of TVOCs appears in 0 o'clock in summer,after 1 o'clock the concentration dropped sharply,the concentration was the lowest at 14 o'clock,and there was an upward trend after 18 o'clock.The concentration of TVOCs was the highest at 6o'clock in spring,autumn and winter,and the lowest at 14-15 o'clock,and increased after 20 o'clock.?3?Harbin's annual atmospheric VOCs contribute to the OFP from large to small,namely olefins>aromatics>alkanes.The most important types of atmospheric VOCs for SOA generation are aromatic hydrocarbons,and the top ten dominant pollutants of SOA are aromatic hydrocarbon compounds,and their potential formation accounts for 88.05%of total SOAP.?4?From June 2017 to May 2018,the ambient air VOCs PMF source analysis results show that the vehicle exhaust emission source is 28.87%,the solvent source is11.73%,the industrial source ratio is 21.32%,the proportion of gasoline volatilization source is 12.40%and the proportion of combustion source is 24.68%.Among them,the exhaust source of motor vehicles is the most contributor among the five pollution sources that remove plant sources,and the combustion source is second only.