Modeling and analysis of PM2.5 generation for key factors identification in China

Recently, the PM2.5 pollution in China has occurred frequently and caused widely concern. In order to identify the key factors for PM2.5 generation, the formation characteristics of PM2.5 would be revealed. A property of electric neutrality of PM2.5 was proposed under the least-energy principle and verified through electricity-charge calculation in this paper. It indicated that PM2.5 is formed by the effect of electromagnetic force, including the effect of ionic bond, hydrogen bond and polarization. According to the analysis of interactive forces among different chemical components, a simulation model is developed for describing the random process of PM2.5 generation. In addition, an orthogonal test with two levels and four factors has been designed and carried out through the proposed model. From the text analysis, PM2.5 would be looser and suspend longer in atmosphere due to Organic Compound (OC) existing (OC can reduce about 67% of PM2.5 density). Considering that NH4+ is the only cation in the main chemical components of PM2.5, it would be vital for anions (such as SO42− and NO3−) to aggregate together for facilitating PM2.5 growing. Therefore, in order to relieve PM2.5 pollution, control strategies for OC and NH4+ would be enhanced by government through improving the quality of oils and solvent products, decreasing the amount of nitrogenous fertilizer utilization, or changing the fertilizing environment from dry condition to wet condition.