Study On The Causes,Sources And Collaborative Control Of PM_2.5 And O₃ Pollution In Typical Area

With the deepening of the battle for air pollution prevention and control,it is more difficult to improve the environmental quality of PM2.5,and O3 pollution is generally on the rise.The causes and sources of PM2.5 and O3 pollution are relatively complex and diverse,and pollution control measures need to be precise and scientific.Taking typical areas of Anhui Province as the research object,this study carried out a study on the spatiotemporal distribution characteristics of pollutants,revealed the causes of PM2.5 and O3 pollution,clarified the sources of PM2.5 and O3 pollution,proposed a multi-pollutant coordinated control strategy based on the environmental quality objectives of PM2.5 and O3,and provided scientific guidance for achieving the improvement of air quality in Anhui Province.In this study,the data of pollutants(PM2.5,NO2,O3)in typical regions of Anhui Province for five consecutive years were obtained by using modern test methods and means such as six-parameter detector of air pollutants,five-parameter detector of meteorology,continuous monitor of volatile organic compounds in the atmosphere,GC-FID/MS,PAN online monitor,HONO online analyzer and solar radiometer Manual and encrypted automatic monitoring data and meteorological(temperature,relative humidity,wind speed,atmospheric pressure,rainfall,total solar radiation,etc.)data,using Pearson correlation analysis,pollutant source analysis model,mesoscale weather forecast model(WRF model),positive definite factor matrix model(PMF model),secondary organic aerosol(SOA)and O3 generation potential(OFP)and other research methods,The spatiotemporal distribution characteristics of pollutants in typical regions of Anhui Province are systematically studied,the cause mechanism and source of PM2.5 and O3 pollution are revealed,and the technical methods and strategies for the coordinated control of pollutants are proposed.The main research results are as follows:1.The spatiotemporal changes of PM2.5 and O3 concentrations in Anhui Province in the past five years were studied,and the results showed that PM2.5 concentrations showed the spatial distribution characteristics of "North Anhui>Central Anhui>South Anhui",and the seasonal changes of "High in winter,low in summer,and middle in spring and autumn".The monthly average and hourly concentrations of PM2.5 in typical areas show "V" and "double peak" patterns respectively.The O3 concentration is characterized by the spatial distribution of "North Anhui>Central Anhui>South Anhui"and the seasonal variation of "high in summer and low in winter,middle in spring and autumn";the monthly average and hourly concentrations in typical areas show "M" and"single peak" patterns respectively.2.Using Pearson correlation analysis,WRF model and other methods,the influence mechanism of meteorology,transmission,natural conditions and photochemistry on the PM2.5 and O3 pollution process was revealed.The PM2.5 and O3 pollution process was divided into three stages:accumulation,pollution and dissipation,and the coupling relationship between the pollutant concentration and temperature,relative humidity,atmospheric pressure,wind speed,total solar radiation and rainfall in each stage was clarified.The influence mechanism of internal and external source transport on pollution transport and pollution degree was studied.The results showed that external source transport aggravated the local pollution degree.The impacts of terrain conditions,land and water differences,urban boundaries and vegetation types on PM2.5 and O3 pollution concentrations were revealed.The photochemical conversion mechanism of PM2.5 and O3 pollution is clarified,and it is concluded that the photochemical conversion of HONO and PANs accelerates PM2.5 pollution and PANs is one of the secondary conversion causes of O3 pollution.3.Using PMF model,SOA,OFP and other analytical methods,the source composition of PM2.5 and O3 is analyzed quantitatively,and it is concluded that PM2.5 pollution mainly comes from vehicle exhaust,biomass combustion and secondary inorganic sources;O3 pollution mainly comes from aromatic hydrocarbons,alkenes,alkynes and OVOCs.4.Through the study on the causes and sources of PM2.5 and O3 pollution,it was found that benzene series and hydrocarbon substances in VOCs were the dominant species of secondary pollution of PM2.5 and O3,and proposed a multi-pollutant collaborative control strategy of "internal control-external coordination-artificial intervention" based on the improvement of the environmental quality of PM2.5 and O3,and issued the "Fourteenth Five-Year Plan for Air Pollution Prevention and Control in Anhui Province"(WHF[2002]No.12),21 local standards of Anhui Province have been formulated in the Technical Specifications for Environmental Management of Volatile Organic Compounds Treatment in Key Industries(DB34/T 4230.1-2022-DB34/T 4230.21-2022).