重庆市主城区春夏季不同粒径颗粒物污染特征分析

Different Diameter Particle Pollution Character of Chongqing Down City in Spring and Summer

采用多通道采样器,采集重庆市主城区PM1.0、PM2.5和PM103种粒径的颗粒物样品,结果显示采样期间PM1.0、PM2.5和PM10日浓度均值分别为0.057 mg/m3、0.075 mg/m3和0.120 mg/m3,主城区颗粒物污染较为严重。对3种粒径颗粒物样品中的碳组分、水溶性组分以及无机污染元素组分进行分析,研究表明各粒径颗粒物中OC所占颗粒物的比重较高,且随着粒径的减少,所占颗粒物的比重却逐渐增加,各粒径中OC/EC的值都超过了2,存在次生有机碳污染。在颗粒物中水溶性组分占颗粒物的比值较大,特别是SO24-、NO3-和NH4+等离子的浓度较高,且主要存在于粒径小于2.5μm的细粒子中,Ca2+和Mg2+存在于粗粒子中。污染元素中S的含量较高,富集因子分析显示Cd、Se、S的富集系数较高,随着粒径的减小,富集现象更加明显。

A URG medium volume particle sampler was used for sampling different diameter particle,the result displayed that the particle pollution in the Chongqing down city was serious,and the daily mean concentration of PM1.0,PM2.5 and PM10 was 0.057 mg/m3,0.075mg/m3 and 0.120 mg/m3 respectively.Analyzing the concentration of carbon component,water-solubility component and inorganic pollution element in different diameter particle,the results showed that the OC had a high proportion in the particles,and the higher the proportion was,the smaller the diameters showed.The OC/EC in the different particles exceeded 2 entirely,which meant the second organic carbon pollution was serious in the down city.SO4 2-,NO3-and NH4 ＋ had higher concentration in water-solubility component,which focused on the particles of diameter less than 2.5 μm,and Ca2＋ and Mg2＋ consisted in coarse particle mostly.Among the pollution elements,S had higher concentration,the enrichment factors showed that Cd,Se,S had large EF value,and the enrichment was obviously among small diameter particle.