朔州市市区环境空气PM10中元素碳、有机碳分布特征

采集朔州市市区采暖季和非采暖季季PM10样品,测定其中元素碳(EC)和有机碳(OC)含量,并对碳组分的浓度水平、时空分布特征和主要来源进行了研究,结果表明:朔州市市区PM10中OC、EC平均浓度分别为(25.95±9.36)μg/m3和(26.58±10.36)μg/m3,总碳气溶胶(TAC)在PM10中的平均百分含量为30.1%;采暖季OC和EC浓度大于非采暖季,且OC、EC质量浓度大小在5个采样点位均呈现出点位5(工业开发区) > 点位2(居民区) > 点位1(商业、居民混合区) > 点位3(商业、文教混合区) > 点位4(相对清洁区)的变化规律,其中,点位5的OC、EC质量浓度最大,分别为(29.66±8.72)μg/m3和(31.40±10.42)μg/m3;PM10中OC/EC在采暖季和非采暖季比值均低于2,一次污染严重;OC和EC相关性较好,相关系数(R2)分别为0.85(采暖季)和0.69(非采暖季),说明PM10中的碳气溶胶主要来源于一次排放源,加强对燃煤烟尘、机动车尾气和生物质的燃烧等空气污染来源的控制对于改善朔州市环境空气质量有重要作用。

Characteristic of organic and elemental carbon in PM10 in Shuozhou City,China

Particulate matter (PM10) samples were collected to study the pollution characteristics of carbonaceous aerosols in Shuozhou, China, during a hot period and a cool period. Organic carbon (OC) and elemental carbon (EC) were analyzed, and the temporal and spatial distributions of OC and EC, as well as the main sources of OC and EC were investigated in detail. The results were as follows. The average concentrations of OC and EC in PM10 samples were (25.95±9.36)μg/m3 and (26.58±10.36)μg/m3, respectively, and the concentrations of total carbon aerosols (TCA) accounted for 30.1% of the PM10. The concentrations of OC and EC during the hot period were higher than those during the cool period, and spatial differences in the OC and EC mass concentrations were detected. Specifically, at five sampling points, the concentrations decreased in the following order: point 5 (industrial development zone) > point 2 (residential areas) > point 1 (business and residential mixed zone) > point 3 (commercial, cultural, and educational mixed zone) > point 4 (relatively clean area). The highest OC and EC concentrations detected were (29.66±8.72)μg/m3 and (31.40±10.42)μg/m3, respectively. All the average values of OC/EC ratios were lower than 2, which indicate that primary pollution sources were predominant. The correlations between OC and EC during the hot period and cool period were good, with R2 values of 0.85 and 0.69, respectively. These data also indicate that the PM10 of carbonaceous aerosols were mainly from primary emission sources. To reduce PM10 concentrations and improve air quality, it will be important for the city of Shuozhou to reduce coal dust releases and emissions from vehicle exhaust, the combustion of biomass, and other sources.