邯郸市PM2.5中碳组分的污染特征及来源分析

为研究邯郸市PM_2.5中碳组分的污染特征及其来源，于2017年4~12月采集PM_2.5样品，用热光反射法（TOR）分析PM_2.5中有机碳（OC）和元素碳（EC）的质量浓度.结果表明：邯郸市PM_2.5和总碳气溶胶（TCA）质量浓度的年均值分别为（88.87±58.89）μg/m³和（31.45±23.35）μg/m³，PM_2.5质量浓度超标率为50%，TCA/PM_2.5比率的年均值为（38.23%±14.61%），表明邯郸市碳组分污染严重.冬季PM_2.5中TCA质量浓度均值为（68.06±23.77）μg/m³，TCA/PM_2.5比率的均值为（46.86%±10.07%），OC（37.09±13.05）μg/m³和EC（8.72±3.78）μg/m³浓度明显高于其它季节，表明冬季碳组分污染较为严重.各季节OC/EC比值均大于2，表明邯郸市全年均受二次有机碳（SOC）的污染；OC、EC及SOC与SO₂、NO₂呈显著正相关，与O₃呈显著负相关，尤其是与NO₂相关关系最强，说明邯郸市碳质气溶胶可能受到机动车尾气排放的影响.对8种碳组分进行主成分分析，发现道路扬尘、燃煤排放和机动车尾气是邯郸市PM_2.5中OC和EC的主要贡献源.

Pollution characteristics and sources of carbon components in PM2.5 in Handan City

In order to study the pollution characteristics and sources of carbon components in PM_2.5 in Handan City, samples of PM_2.5 were collected from April to December 2017 and the mass concentrations of organic carbon (OC) and elemental carbon (EC) in PM_2.5 were analyzed by thermal optical reflection (TOR). The results showed that the average annual concentrations of PM_2.5 and total carbon aerosol (TCA) were (88.87±58.89)μg/m³ and (31.45±23.35)μg/m³ respectively. The exceeding standard rate of PM_2.5 concentration was 50%, and TCA accounted for (38.23%±14.61%) of PM_2.5 during the sampling period, indicating that the pollution of carbon components was serious in Handan. The average mass concentration of TCA was (68.06±23.77)μg/m³ in winter, which contributed (46.86%±10.07%) to PM_2.5, and the concentrations of OC (37.09±13.05)μg/m³ and EC (8.72±3.78)μg/m³ in winter were higher than other seasons, indicated the carbon aerosol was polluted seriously. The OC/EC ratio was higher than 2 in each season, which indicated that Handan was polluted by secondary organic carbon (SOC) all year round. OC, EC and SOC were significantly positively correlated with SO₂ and NO₂, and negatively correlated with O₃ especially the correlation between carbon components and NO₂ was the strongest, indicating that the carbon component was most likely affected by vehicle exhaust emissions. Principal component analysis of the eight carbon components showed that road dust, coal combustion and vehicle exhaust were the main contributors to OC and EC in PM_2.5 in Handan City.