The Study On Distribution Of SO₂,NO₂,PM_2.5 And PM₁₀ In The Atmosphere Of Dalian City And Their Influencing Factors

In tihe process of rapid development of economy and rapid progress of urban construction,air pollution in our country becomes more and more serious.Urban air pollution restricts the sustainable development of society and economy to a certain extent,causing great harm to the health of residents.It is urgent to control urban air pollution.The premise and basis for combating air pollution is to have comprehensive air pollution data,and to conduct scientific and accurate analysis and evaluation of the primary pollutants and related impact factors that affect air quality.And study the law of its corresponding changes.In order to understand the current situation of atmospheric pollution in Dalian and to study the main sources and influencing factors of atmospheric pollutants,6 major pollutants based on participation in environmental quality assessment(SO2,NO2,PM10,PM2.5,CO,and O3).In this paper,fine particulate matter(PM2.5),respirable particulate matter(PM10),sulfur dioxide(SO2)and nitrogen dioxide(NO2)in the air of Dalian City are studied.This paper introduces the components,hazards and methods of automatic monitoring of SO2,NO2,PM10 and PM2.5.By recording and collating the relevant monitoring data from 2013 to 2017,this paper analyzes and discusses the changing laws of atmospheric pollution in Dalian city and the relevant causes of pollution,so as to provide a technical support for scientific control of atmospheric pollution in the future.From the time change,the concentration of SO2 was significantly higher in winter than in summer in the four seasons,and SO2 showed obvious "double peaks"during the heating period.The two peaks that appeared throughout the day were the starting hours of the heating boiler;The concentration of SO2 was relatively stable during the non-heating period.NO2 concentration is also significantly higher in winter than in summer.The non-heating period is mainly increased in the morning and evening traffic peak NO2 concentration.During the heating period,the all-day trend is M type.The mean value is higher than that of the non-heating period and the characteristics of the double peaks are obvious.The superposition effect of traffic peaks and heating peaks;The concentration of PM 10 and PM2.5 in the spring and winter seasons was significantly higher than the summer concentration.In the heating period,it was higher than the non-heating period.The daily mean change law of the heating period was relatively obvious,and the trend of the whole day was M-type.There are two peaks in the non-heating period in the morning and evening,but the change law and amplitude are not obvious.This is because the emission of vehicle exhaust gas willhave a certain impact on the concentration of PM10 and PM2.5 during the morning and evening rush hours of the non-heating period.During the heating period,the superposition effect of coal heating and automobile exhaust emissions at the peak of morning and evening travel will have a certain effect on the concentration of PM10 and PM2.5.Taking the 24-hour mean data of SO2,NO2,PM10 and PM2.5 in 2016 as an example,The correlation strength between PM 10 and PM2.5 is extremely strong by the Pearson correlation coefficient,PM10,PM2.5 and NO2 are strongly correlated,PM10,PM2.5 is related to the middle strength of SO2,NO2 is related to SO2's moderate strength,and combined with the correlation between SO2,NO2,PM10 and the mean change trend of PM2.5 months,seasons,and years,it is judged that SO2,NO2,PM10 and PM2.5 are roughly the same as the main source of pollution.However,the correlation between SO2 and particles is not strongly related,because SO2 in the atmosphere reacts to form sulfates and consumes some of them under certain conditions,and the concentration of particles caused by secondary sulfates increases,In addition,SO2 is different from the main source of particulate matter during the non-heating period.The emission of automobile exhaust gas has a greater impact on PM10 and PM2.5.SO2 and NO2 have some differences in the trend outside the heating period,indicating that the main sources of pollution between NO2 and SO2 are different during the non-heating period.NO2 is mainly affected by a large number of vehicle exhaust emissions.Taking the heavy pollution weather formation in Dalian city in 2015 and 2016 as an example to analyze,it is also one of the factors that affect the distribution status and concentration of local pollutants.Finally,by adjusting the energy consumption structure,controlling emissions from industrial sources,controlling motor vehicle emissions,and improving the air quality forecast and warning,the relevant measures for the control of air pollution in Dalian city are discussed.