Atmospheric deposition fluxes of 7Be, 210Pb and 210Po at Xiamen, China

摘要

The atmospheric deposition fluxes of 7Be, 210Pb and 210Po at Xiamen were measured. The samples were collected from March 2004 to April 2005 and the sampling period was one month. The 7Be and 210Pb activity were measured using HPGe γ-spectrometer after concentration using Fe(OH)3 co-precipitation method. The 210Po was counted with an α-spectrometer after the sample was digested and spontaneous plated onto a silver planchet. At Xiamen, the atmospheric deposition fluxes of 7Be varied between 0.11 and 2.93 Bq·m?2·d?1 and the average was 1.64 Bq·m?2·d?1; 210Pb fluxes varied between 0.04 and 0.85 Bq·m?2·d?1, and the average was 0.51 Bq·m?2·d?1; 210Po fluxes varied between 0.002 and 0.133 Bq·m?2·d?1, and the average was 0.061 Bq·m?2·d?1. There were positive correlations between the deposition fluxes of 7Be, 210Pb or 210Po and the amount of precipitation. The residence time of aerosols varied between 6.0 and 54.0 days with a mean of 27.1 days, which were calculated by 210Po/210Pb fluxes ratios.