Acidity of Aerosols during Winter Heavy Haze Events in Beijing and Gucheng, China

• DOI: 10.1007/s13351-018-7063-4
• Publication Date: 2018-02-26T06:47:22Z
• Authors: Xiyuan Chi; Pengzhen He; Zhuang Jiang; Xiawei Yu; Fange Yue; Longquan Wang; Bokun Li; Hui Kang; Cheng Liu; Zhouqing Xie
• Keywords: Haze; Inorganic ions

We investigated the acidity and concentrations of water-soluble ions in PM2.5 aerosol samples collected from an urban site Beijing a rural Gucheng, Hebei Province November 2016 to January 2017 gain insight into formation secondary inorganic species. The average SO42–, NO3–, NH4+ were 8.3, 12.5, 14.1 μg m–3, respectively, at 14.0, 14.2, 24.2 site. nitrogen sulfur oxidation ratios correlated with relative humidity (with correlation coefficient r = 0.79 0.67, respectively) loadings. Based on parameterization model, we found that rate constant heterogeneous reactions for SO2 polluted days was about 10 times higher than clear days, suggesting water played essential role haze events. ISORROPIA II model used predict pH, which had mean (range) 5.0 (4.9–5.2) 5.3 (4.6–6.3) site, respectively. Under conditions this predicted pH value, by dissolved NO2 hydrolysis N2O5 may be major forming SO42– NO3– haze. also analyzed sensitivity changes under conditions. more sensitive opposing trends, concentrations. relatively weak overall, attributed buffering effect NH3 partitioning.