香河夏季PM2.5水溶性无机离子组分特征

2013年6月在中科院香河观测站对大气气溶胶化学组分特征进行研究.对PM2.5和PM10质量浓度进行在线监测,结果表明,观测期间PM2.5和PM10质量浓度均值与方差分别为(151.78±82.48)μg/m3和(250.47±106.99)μg/m3;SNA(SO42-、NO3-、NH4+)占PM2.5质量浓度的44.8%,且大多富集在粒径0.5~2.5μm的细颗粒物中.硫氧化率(SOR)、氮氧化率(NOR)平均值分别为0.35、0.31,SO2主要通过非均相的氧化反应转化为SO42-,NOx主要通过白天光化学反应转化为NO3-;灰霾和轻雾天较高的SOR和NOR表明,灰霾和轻雾天相比于清洁天有较多的SO2、NOx转化为SO42-、NO3-.气流后向轨迹分析表明灰霾和轻雾天空气质量受经过河北、山东及江苏北部气流影响.

Characteristics of water-soluble inorganic ions of PM2.5 in summer at Xianghe

Chemical characteristics of aerosols in summer were studied during June of 2013 in Xianghe observation station of the Chinese academy of sciences. Mass concentrations of PM2.5 and PM10 were recorded by online measurement. The result showed mass concentrations of PM2.5 and PM10 were (151.78±82.48) μg/m3and (250.47±106.99) μg/m3with average and standard deviation. SNA (SO42-, NO3-, NH4+) accounted for 44.8% of PM2.5, and it mainly enriched in the particles which size range from 0.5 to 2.5 micrometers. The average of SOR and NOR were 0.35, 0.31, respectively. The transformation method of SO2 into SO42- was heterogeneous reaction, and NOx transformed into NO3- was mainly by photochemical reaction during the daytime. The high value of SOR and NOR during haze and mist indicated that there is more SO2 and NOx into SO42- and NO3- in haze and mist favor transformation of sulfur and nitrogen, rather than in clear day. The backward trajectories analysis showed air quality in haze and mist were influenced by air masses mainly passing through Hebei, Shandong, and the north of Jiangsu Province.