Research On Diurnal Variation Of Atmospheric Particulates In Kaifeng City

The atmospheric particles can cause lots of hazards to human beings, for example theycan reduce the atmospheric visibility, pollute our atmospheric environment and even threatenthe human health. Especially the fine particles, because of their much smaller graindiameter,this kind of atmospheric particle has more serious harm to human health that theyhave gained increasing concerns by the public. Therefore, in this paper the mass concentrationand metal elements content of atmospheric particles, and the diurnal variation of differentparticle sizes of atmospheric particles in different weather conditions were analyzed bymonitoring and sampling in the different functional areas of Kaifeng City. The major studypurpose of this paper was to get preliminary understanding about the basic variation rules andpollution sources of atmospheric particles in Kaifeng City, and finally tried to provide a newscientific basis about the air pollution control and comprehensive treatment for theenvironmental administrations of Kaifeng City.The monitoring and sampling work were carried out during the October1st–October22th, and the December1st-December20thof2011.According to the functional zoningprinciples,the Longting Park which is a tourist and residential area and the Diesel EngineFactory which is a representative of industrial area were chosen as the monitoring andsampling sites in this study. The diurnal variation characteristics of mass concentration underdifferent conditions in PM₁₀, PM_2.5and PM_1.0, and the diurnal variation characteristics ofmetal element content in PM₁₀and PM_2.5were analyzed. Finally, the study results are asfollows.(1) Diurnal variation characteristics of mass concentration of different grain diameteratmospheric particles: Under the general weather conditions in autumn and winter, the diurnal variation of PM₁₀presented "Twin peaks double valley" that it was high during the day whilelow at night. The PM_2.5also presented the "Twin peaks double valley" changes, but it had lowvariation in the day and high variation at night. For PM_1.0, it had few changes in the diurnalvariation of autumn and winter, and the hour changes during a day also showed more gently.The comparison of the diurnal variation of atmospheric particles in two sampling sitesshowed that the mass concentrations of PM_2.5and PM_1.0in Diesel Engine Factory in autumnand winter.were higher than the mass concentrations in Longting Park. However, the PM₁₀showed different changes in two sampling sites in two seasons that its mass concentrationswas higher in Diesel Engine Factory in autumn while had no significant change in winter inthe two sampling sites;(2) Diurnal variation characteristics of mass concentration of atmospheric particles inwork days and rest days: The diurnal variation of mass concentration in PM₁₀and PM_1.0showed similar changes in work days and rest days that they both presented the "Twin peakstwo vales" situation with high variation during the day and low variation at night. The diurnalvariation of mass concentration in PM_2.5also presented the "Twin peaks two vales" in workdays and rest days, however, it had high variation during the day and low variation at night inworking days but opposite changes in rest days.(3) Diurnal variation characteristics of mass concentration of atmospheric particles inhazy days and non-hazy days: The diurnal variation of PM_2.5and PM_1.0had synchronouschanges in hazy days and non-hazy days. In hazy days, the mass concentrations of fineparticles were mainly affected by the meteorological factors but not the traffic source. ForPM₁₀, its mass concentration presented the "single peak and single vale" situation in hazydays while opposite situation of the "Twin peaks Twin vales" in non-hazy days.(4) Diurnal variation characteristics of metal elements in atmospheric particles: Thediurnal variation of most metal elements in PM₁₀and PM_2.5both presented "Inverse U" types that they had high variation during the day and low variation at night before and after theheating season. Except the Mn and Co in PM₁₀, PM₁₀and PM_2.5had relatively high metalelements concentration after the heating season, and especially the elements of Zn and Fewhich had severe concentration changes before and after the heating season in two samplingsites. The diurnal variation of metal elements in PM₁₀, PM_2.5and PM_1.0consisted of an"Inverse U" type which meant high variation during the day and low variation at night, a"U" type which showed low variation during the day and high variation at night, and typesof "Wavy Shape rise" and "Wavy Shape fall" and so on. The diurnal variation of metalelements in different atmospheric particles had similar changes in hazy days and non-hazydays. The mass concentrations of metal elements in hazy days were not always higher thanthe metal elements concentration in non-hazy days, but the metal elements in PM_2.5showedgenerally higher concentration in hazy days than in non-hazy days in winter. This indicatedthat there was relatively serious air pollution of PM_2.5in winter hazy days.(5) The study results of analyzing thirteen metal elements in different atmosphericparticles in Kaifeng City by Factor Analysis were indicated that the major resources ofatmospheric particles in Kaifeng City were including soil dust, metallurgy and chemical dust,coal fuel dust, the automobile exhaust dust, waste incineration dust and so on. Moreover,most of the atmospheric particles resources were mixed dust resources which consisted ofsoil, metallurgy and coal fuel dust.