典型重工业城市空气重污染过程特征与来源解析

为揭示邯郸市空气污染过程及形成原因，以邯郸市环境监测中心为采样点，对采样滤膜进行离子和碳质组分测试，探讨PM_2.5组分浓度变化特征，并利用WRF-CAMx空气质量模型模拟分析2017~2018年秋冬季3次重污染前后邯郸市各个地区各类污染源大气污染排放对PM_2.5质量浓度的贡献.结果显示，重污染期间邯郸市水溶性粒子占PM_2.5质量浓度的62.4%，二次离子中呈现NO₃^- > SO₄^2- > NH₄⁺变化趋势.受地面均压场和高压底部控制及500hPa高空纬向环流影响，污染物水平方向和垂直方向传输受到抑制，同时边界层高度的降低进一步加剧PM_2.5污染浓度的升高，随着西伯利亚东部高压和欧亚大陆高压南下以及边界层高度的上升，3次重污染过程得以彻底清除.PSAT示踪模块结果表明复兴区，丛台区和永年区是邯郸市PM_2.5浓度贡献的主要区县，3个区县重污染贡献总和为66.8%~72.2%，重污染时段冶金，交通源和居民散煤燃烧是3大主要污染源.

Characteristics of heavy pollution process and source appointment in typical heavy industry cities

In order to study the process and causes of air pollution in Handan City, we measured the inorganic ion and carbon component to analyze the variation characteristics of PM_2.5 from samples taken at the site of Environmental Monitoring Center of Handan was selected to sample the PM_2.5 concentrations and measure the inorganic ion and carbon component. The air quality model of WRF-CAMx was used to simulate and analyze the PM_2.5 mass concentration contribution of different emission sources in various regions during three heavy pollutions in autumn and winter of 2017~2018. The results showed that water-soluble particles accounted for 62.4% of PM_2.5 mass concentration in Handan during heavy pollution. The secondary ions showed a trend of NO₃^- > SO₄^2- > NH₄⁺. During the three continuous heavy pollution processes in Handan City, the pollution was affected by the ground uniform pressure field, the bottom of high pressure and the zonal circulation of 500hPa at high altitude. The horizontal and vertical transports of pollutant were inhibited. The decrease of boundary layer height further resulted in the increase of PM_2.5 mass concentration. The three heavy pollutions were completely removed with the southward move of Eastern Siberia high pressure and Eurasian Continental high pressure and increase of the boundary layer height. The results of PSAT tracer module showed that the Fuxing District, Congtai District and Yongnian District were the main districts and counties contributing PM_2.5 in Handan City, with the total contribution ranging from 66.8% to 72.2%. The metallurgy, mobile source and residential bulk coal combustion were the three major pollution sources during the heavy pollution period.