大气气溶胶5个种态中元素分布特征的研究

Study on the Element Distribution Complexion in Five Phase of Atmosphere Aerosol

应用化学逐级提取流程对国际原子能机构提供的气溶胶和大气气溶胶中元素的组成和种态(phase)进行了分析,应用仪器中子活化法测定了水可溶态、碳酸盐态、氧化物态、有机物态和不溶物态中元素的含量,计算出元素在5个种态中的富集因子和分布比例。本工作制定的种态分析流程准确度和精确度较好,可用来对采集在滤膜上的气溶胶进行分析。实验数据表明,大气气溶胶中的不同元素在5个种态中的富集程度有很大差异。地壳来源元素,它们的总量富集因子小于10,为不富集,但在某一种态中却能发生富集,富集因子大于10,如Ca、Mg、Ba、Co、Cs、Mn和Rb在水可溶态中是富集的,U在碳酸盐态是富集的。人为来源元素在总量中富集,但在5个种态里存在差别,如Sb和Se在5个种态中都富集,Br和Mo在氧化物态和不溶物态中富集因子小于10,As和Zn在不溶物态中富集因子小于10。元素在5个种态中的分布比例也有很大差别,有的集中在1个种态,有的集中在2或3个种态,如Ca集中在水可溶态,Cr在氧化物态,Br在碳酸盐态;Sb集中在水可溶态和不溶物态,Se在水可溶态和有机物态;Cu集中在水可溶态和有机物态及氧化物态。水可溶态、碳酸盐态和有机物态沉降后容易进入环境。氧化物态和不溶物态比较稳定,不易进入生态系统。不论地壳来源还是人为来源的元素,只是其?

The five-stage sequential extraction procedure is applied for element composition and phases in atmosphere aerosol and aerosol supplied by International Atomic Energy Agency(IAEA). Instrumental Neutron Activation Analysis(INAA) are used to determine the elemental composition of dissoluble phase, carbonate phase, oxide phase, organic phase and indissoluble phase. Distribution proportions and Enrichment Factors (EF) of elements in five phases are calculated. The accuracy and precision of this sequential extraction procedure are good, and can be applied to aerosol samples loaded on air filters. Experiment data show that elements have various distribution complexions in different phases. The whole EF values of lithosphere source elements are less than 10, but the EF values of elements Ca, Mg, Ba, Co, Cs, Mn, Rb in dissoluble phase and U in carbonate phase are large than 10. The whole EF values of anthropogenic pollutant elements are large than 10. The EF values of elements Sb, Se in five phases are large than 10, but the EF values of elements Br, Mo in oxide phase and indissoluble phase and As, Zn in indissoluble phase are less than 10. Ca mainly enrich in dissoluble phase. Cr mainly enrich in oxide phase.Br mainly enrich in carbonate phase. The element Sb has higher concentrations in dissoluble phase and indissoluble phase. The element Se has higher concentrations in dissoluble phase and organic phase. The element Cu has higher concentrations in dissoluble phase, organic phase and oxide phase. When aerosol deposit on the earth's surface by dry and wet removal processes, dissoluble phase can directly enter water circulation. In proper condition, carbonate phase and organic phase can react with other compound in environment to enter ecosystem as water dissoluble compound, thus have strong influences to environment. Oxide phase and indissoluble phase does not easily react after they deposited, and has little effect to environment.