徐州市大气PM_(2.5)污染特征和来源解析

Characteristic and Source Apportionment of PM2. 5in Xuzhou

于2016年4月、7月、10月和2017年1月利用2台中流量分别在徐州市不同功能区,即生活区、工业区和旅游区采样大气中的细颗粒物(PM_(2.5))样品,测定PM_(2.5)质量浓度及其化学组分(含碳组分、水溶性离子和无机元素),结合化学质量平衡模型(CMB),对PM_(2.5)进行来源解析。研究结果表明:徐州市PM_(2.5)污染的年平均浓度维持在65μg/m^3左右,超过国家环境空气质量标准(GB3095-2012)二级标准(35μg/m3)的0.95倍。冬季全市的PM_(2.5)平均浓度最高,为103.6μg/m^3。根据CMB模型结果,全年PM_(2.5)来源解析,煤烟尘的分担率最高,达23.4%;其次是硫酸盐,达20.5%;硝酸盐的分担率占第三位,为18%,机动车尾气尘和城市扬尘分别为12.3%和11.4%,其他各源类的分担率均小于5%。

Two mid-volume air sampler were used to collect the r PM_（2.5） samples from three districts-living area,industry area and tourism area in Xuzhou during April,July,October 2016 and January 2017. The inorganic elements,the water-soluble ion and the carbon element were determined and compared. Chemical mass balance（ CMB） model was applied to analyze the source apportionment of PM_（2.5） in Xuzhou. The results show that the annual average of PM_（2.5） concentration is 65μg/m^3,and1. 95 times than the new Grade Ⅱ national standards for air quality（ 35μg/m3）. The concentration of PM_（2.5） in winter was the highest and the data was 103. 6μg/m3. According to the CMB model,The whole year source apportionment result of PM_（2.5） in Xuzhou indicates that the source of PM_（2.5） was coal combustion dust（ 23. 4%）,sulfate（ 20. 5%）,nitrate（ 18%）,vehicle exhaust（ 12. 3%）,urban resuspended dust（ 11. 4%）. Meanwhile the contribution of other source was less than 5%.