Analysis Of Water-Soluble Ion Pollution Characteristics And Sources In Atmospheric PM_2.5 In The North Suburb Of Nanjing In 2015

It is important to analyze the pollution of PM_2.5 and its water-soluble components in the northern suburbs of Nanjing.It is of great significance to evaluate the source of pollutants and the harm to health.In this paper,we study the PM_2.5 in the northern suburbs of Nanjing,The pollution level of water-soluble ions,the pollution characteristics,the correlation between water-soluble ions and so on,and the factor analysis method was used to analyze the source of water-soluble ions.The results show:?1?A total of 158 PM_2.5 samples?24 hours per day?were collected in the northern suburbs of Nanjing in 2015.The PM_2.5 concentration had obvious seasonal variation and diurnal variation,The seasonal average concentration of PM_2.5 was in winter?96.82?g/m3?>autumn?77.91?g/m3?>spring?70.27?g/m3?>summer?42.62?g/m3?.?2?In this study,nine water-soluble ions of F^-?Cl^-?NO₃^-?SO₄^2-?Na⁺?NH₄⁺?K⁺?Ca²⁺?Mg²⁺ were analyzed by ion chromatography?IC?.The total concentration of water-soluble ions in PM_2.5 in the northern suburb area of Nanjing was in the range of 9.3?131.78?g/m3,with an average value of 43.27?g/m3.The water soluble ion component of PM_2.5 accounts for 59.22%of the total mass of PM_2.5.It can be found that water-soluble ions are important components of PM_2.5.SO₄^2-?NH₄⁺?NO₃^- are the three main water-soluble ions in PM_2.5 in the northern suburbs of Nanjing in 2015.The three kinds of ions produced the highest contribution in autumn and the lowest contribution in summer.?3?Through the correlation analysis between the ions found in the autumn and winter season NH₄⁺ is preferred with NO₃^-.Summer meteorological conditions and emission characteristics are more conducive to the combination of NH₄⁺ and SO₄^2-.The NH₄⁺,NO₃^-and SO₄^2-in PM_2.5 were mainly in the form of NH₄HSO₄ and NH₄NO₃.The NH₄⁺,NO₃^-and SO₄^2-in PM_2.5 were mainly in the presence of NH₄HSO₄ and NH₄NO₃.Through the balance analysis of anions and cations,it can be found that the total ion level in the summer and autumn seasons is relatively alkaline,and the relative loss of anions is relatively weak.?4?The analysis of the source of water-soluble ions in PM_2.5 in the northern suburbs of Nanjing by factor analysis revealed that the main changes were due to the following sources:industrial emissions?Contribution rate of about 13.35%?16.56%?,soil and building dust?Contribution rate of about 21.04-33.63%?,biomass fuel and fossil fuel combustion?Contribution rate of about 26.68%?37.01?,VehiCle exhaust emissions?Contribution rate of about 23.17%?33.82%?.