Research On The Interaction Between Ozone And Particulate Pollution In The Beijing-Tianjin-Hebei Region

With the rapid development of the economy,the urban community is accompanied by the severe aggravation of air pollution.At present,the Beijing Tianjin Hebei region is facing very serious complex air pollution in summer.In recent years,complex air pollution caused by particulate pollution and photochemical pollution has become an important pollution problem of large urban agglomerations,which has aroused widespread concern in the scientific community,government departments and the public.Complex pollution has caused a sharp decline in air quality and a sharp decrease in visibility,and also has a serious impact on the environment and human health.In this paper,we analyzed the meteorological observation data and the pollution data in Beijing,Tianjin and Shijiazhuang in 2014,studied the relationship between the ozone and the particles in the area,and analyzed the sources of VOCs in the Beijing region.The results of the study are as follows:The annual mean concentration of fine particulate matter?PM2.5?was84±70?g·m^-3,86±60?g·m^-3,and 118±9?g·m^-3 in Beijing,Tianjin,and Shijiazhuang,respectively.The mean O_{38 h max} in the summer was 171±43?g·m^-3,147±45?g·m^-3,and146±44?g·m^-3,respectively.The mean O3₈ h max in the summer was 171±43?g·m^-3,147±45?g·m^-3,and146±4?g·m^-3,respectively.This research indicates that PM_2.5and O3 are positively correlated when the temperature exceeds 20°C,and the urban agglomeration shows characteristics of complex air pollution consisting of superimposed O3 and PM2.5.In summer,when the humidity was less than 55%,secondary particles and O3 also increased in a coordinated manner?y=1.35x+29.85;R²=0.61?,which demonstrates severe complex pollution.However,the mean PM2.5?y?and mean O3₈ h max?x?in summer showed a negative correlation?y=-1.3x+245;R²=0.61?in the three regions,indicating high concentrations of PM2.5 pollution partially inhibit O3 generation.When the high concentration of PM2.5drops,the solar radiation is enhanced and the ozone concentration will increase further.This will cause problems in curbing air pollution in Beijing,Tianjin,and Shijiazhuang.When primary particulate matter pollution was under control,O3concentrations rose rap-idly,causing serious photochemical pollution.In summer,the formation of ozone in Beijing is mainly controlled by VOCs.The mean concentration ofTVOCs was?30.69±12.56?×10^-9,including alkanes?14.22+7.48?×10^-9,olefins?5.35±2.16?×10^-9,and aromatics?11.12±4.69?×10^-9.The source apportionment of VOCs in summer shows that there are mainly 4 sources of VOCs in Beijing:organic solvent source,vehicle exhaust,plant emission source and industrial production source.When the temperature is below 24?,AOD and O₃ are negatively correlated?y=-9.1x+181.4?,the formation of ozone is inhibited when the aerosol extinction enhancement is enhanced.At the same time NCAR MM model shows,the contribution of VOC components to ozone generation in summer is mainly from olefin?alkene>alkane.And when AOD decreased from 2 to 0.2,the ozone concentration increased from?175²07??g·m^-3to?195²14??g·m^-3,indicating thathigh concentration particle matters would inhibit ozone generation.