Atmospheric Oxidation Capacity and Its Impact on the Secondary Inorganic Components of PM2.5 in Recent Years in Beijing: Enlightenment for PM2.5 Pollution Control in the Future

In recent years, the concentrations of PM2.5 in urban ambient air China have been declining; however, strong atmospheric oxidation capacity (AOC) represents challenges to further reduction concentration and continuous improvement quality future, since overall AOC is still at a high level. For this paper, based on ground observation data recorded Beijing from 2016 2019, variation was characterized according odd oxygen (OX = O3 + NO2). The primary secondary components were analyzed using empirical formulas, correlation between inorganic (SO42−, NO3−, NH4+, SNA) explored, impact photochemical reaction activity generation particles evaluated, variations SNA investigated. results revealed that OX reached their peak lowest point 2019. followed descending seasonal trend summer, spring, autumn, winter, along with spatial stations suburban background stations. degree magnitude large influence production particles. When more active stronger, mass generated fraction higher accounted for proportion total concentrations. fraction, 50.7% 94.4% water-soluble ions field observations. Higher oxidant corresponded sulfur ratio (SOR) nitrogen (NOR), suggesting increase could promote concentration. Based relationship analysis SOR, NOR, OX, it inferred SOR NOR both nonlinear. Therefore, when establishing control strategies should be fully considered, favorable measures taken properly regulate AOC, which would effective carrying out regarding pollution.