百色市PM_(10)和PM_(2.5)中有机碳和元素碳污染特征及来源解析

Pollution Characteristics and Source Apportionment of Organic Carbon and Elemental Carbon in PM_(10) and PM_(2.5) in Baise

2015—2016年在百色市布设3个采样点采集PM_(10)和PM_(2.5)样品,分析其中有机碳(OC)和元素碳(EC)的含量。结果表明,PM_(10)和PM_(2.5)中OC、EC四季均值分别为15.0μg/m^3、5.55μg/m^3和11.7μg/m^3、4.72μg/m^3;OC与EC相关性不显著,存在不同的污染来源;OC/EC值多数>2,存在二次污染,主要来源于柴油、汽油车尾气和燃煤的排放。由总碳质气溶胶(TCA)和8个碳组分丰度分析可知,百色市碳气溶胶(CA)来源于汽车尾气、道路扬尘、燃煤的排放。二次有机碳(SOC)在OC中的占比均>75%,表明百色市大气颗粒物中OC以SOC为主,夜间污染重于昼间。

PM10 and PM2.5 samples were collected at three sampling sites in Baise for analyzing the content of organic carbon(OC)and elemental carbon(EC)from 2015 to 2016.The results showed that the seasonal means of OC and EC content in PM10 were 15.0μg/m^3 and 5.55μg/m^3,while in PM2.5 were 11.7μg/m^3 and 4.72μg/m^3,respectively.There was no significant correlation between OC and EC,indicating they had different pollution sources.The OC/EC ratio was over 2,indicating there was secondary pollution and the main sources were vehicle exhaust from diesel and petrol,and coal combustion.The analysis results of total carbon aerosol(TCA)and the abundance of eight carbon components showed that the carbon aerosol(CA)in Baise was mainly derived from car exhaust,road dust,and coal combustion.Secondary organic carbon(SOC)accounted for over 75%of OC,indicating SOC was dominated in OC in atmospheric particulate matter,and the pollution at night was more serious than that in daytime.