Seasonal Variation Of Water-Soluble Inorganic Ions In PM_2.5 In The Southern Suburbs And Urban Areas Of Beijing

Atmospheric particulates can affect atmospheric environmental quality,climate,and human health.Water-soluble inorganic ions as an important component in fine particles,its concentration and composition changes have an impact on precipitation,atmospheric visibility and cloud formation process,and even its transmission process involves cross-regional pollution.In this study,the rapid collection of atmospheric fine particles and the chemical composition online analysis system?RCFP-IC?independently developed by the Institute of Atmospheric Physics,Chinese Academy of Sciences,were used to conduct the water-soluble inorganic ions in atmospheric PM_2.5 in the southern suburbs and urban areas of Beijing for a duration of 1 year.Simultaneous observational studies have described the characteristics of water-soluble inorganic ions in the process of typical pollution events in the southern suburbs and urban areas,and explored the differences in the sources of water-soluble inorganic ions in the southern suburbs and the urban areas and the transmission paths of pollutants to the pollution process.Impact,which further lays the foundation for the study of eco-environmental utility.In this study,the rapid capture of atmospheric fine particles and the chemical composition online analysis system?RCFP-IC?independently developed by the Institute of Atmospheric Physics,Chinese Academy of Sciences,were used to conduct the 1a-long water-soluble inorganic ions in atmospheric PM_2.5 in the southern suburbs of Beijing.Synchronous observation studies have described the characteristics of water-soluble inorganic ions during the typical pollution events in the southern suburbs and urban areas,and discussed the seasonal changes of water-soluble inorganic ions in the southern suburbs and urban areas and the main factors affecting the pollution in the two regions,and further It lays the foundation for the study of eco-environmental utility.The results show:?1?Total water-soluble inorganic ions concentration in winter in urban areas:SO₄^2->NH₄⁺>NO₃^->Cl^->K⁺>Ca²⁺>NO₂^->Na⁺>Mg²⁺,total mass concentration of water-soluble inorganic ions in southern suburbs:SO₄^2->NO₃^->NH₄⁺>Cl^->Ca²⁺>K⁺>NO₂^->Na⁺>Mg²⁺,The main water-soluble inorganic ions in the two regions are SO₄^2-?NH₄⁺?NO₃^-and Cl^-.In the process of pollution,the main source of the pollution in the two regions is the secondary source,the mixed source of soil wind,dust and building dust.The meteorological factors affecting the formation of pollution in the southern suburbs are the low temperature and the height of the low mixed layer,and the pollutants that are transported outside,the meteorological factors affecting urban pollution formation are low temperature,low wind speed,low mixed layer height,and accumulation of local source pollutants.?2?The water-soluble inorganic ions in urban areas in spring are SO₄^2->NH₄⁺>NO₃^->Cl^->Ca²⁺>NO₂^->K⁺>Na⁺>Mg²⁺,and the water-soluble inorganic ions in the southern suburbs are SO₄^2->NO₃^->NH₄⁺>Ca²⁺>Cl^->NO₂^->K⁺>Na+>Mg²⁺,the main water-soluble inorganic ions in the two regions are SO₄^2-,NH₄⁺,NO₃^-,and Ca²⁺.In the process of pollution,the southern suburbs dominated by local dust,and dust transport from outside the city dominated.The increase of secondary ion concentration in the southern suburbs was mainly affected by the high air mass in the south.The source of urban dust pollution was mainly affected by the low air mass in the northwest.?3?In summer,the water-soluble inorganic ions in the urban area are SO₄^2->NH₄⁺>NO₃^->Ca²⁺>Cl^->NO₂^->Mg²⁺>K⁺>Na⁺.The water-soluble inorganic ions in the southern suburbs are SO₄^2->NO₃^->NH₄⁺>Cl^->NO₂^->Na⁺>Ca²⁺>Mg²⁺>K⁺.The main water-soluble inorganic ions in the two regions are SO₄^2-,NH₄⁺,NO₃^-and Cl^-.During the pollution process,the concentration of water-soluble inorganic ions in the two regions varies depending on the amount of SO₄^2-generated.The sources of pollution in the southern suburbs and urban areas are mainly mobile sources,but fixed sources cannot be ignored.The pollution in the southern suburbs and the urban areas is affected by the South pollution air masses.?4?In the autumn,the water-soluble inorganic ions in the urban area are SO₄^2->NH₄⁺>NO₃^->K⁺>Cl^->Ca²⁺>NO₂^->Na⁺>Mg²⁺,and the water-soluble inorganic ions in the southern suburbs are SO₄^2->NO₃^->NH₄⁺>K⁺>Cl^->Ca²⁺>NO₂^->Na⁺>Mg²⁺,the main water-soluble inorganic ions in the two regions are SO₄^2-,NH₄⁺,NO₃^-,and K⁺.In the process of pollution,the slow and sustained southwest wind in high humidity and calm weather is the main meteorological factor for the formation of pollution.The main sources of pollution in the southern suburbs are secondary sources,dust sources,biomass combustion sources,and their pollution is mainly affected by low-level air pollution in the southwest.In summary,the main meteorological factors affecting the pollution in the southern suburbs and the urban areas are temperature,relative humidity,height of mixed layers,and wind speed and direction,and the role of southward contaminated air mass will accelerate the formation of pollution in the southern suburbs.