北京市PM2.5中砷污染特征  

Chemical Characteristics of Arsenic in PM2.5 in Beijing

作　　者：石绍萱 杨艳蓉 秦娟娟 周雪明 段菁春[3] 谭吉华 陈荣志[1,2] SHI Shao-xuan;YANG Yan-rong;QIN Juan-juan;ZHOU Xue-ming;DUAN Jing-chun;TAN Ji-hua;CHEN Rong-zhi(College of Resources and Environment,University of Chinese Academy of Sciences,Beijing 100049,China;Research Center for Eco-Environmental Sciences,Chinese Academy of Sciences,Beijing 100085,China;State Key Laboratory of Environmental Criteria and Risk Assessment,Chinese Research Academy of Environmental Sciences,Beijing 100012,China)

机构地区：[1]中国科学院大学资源与环境学院,北京100049 [2]中国科学院生态环境研究中心,北京100085 [3]中国环境科学研究院环境基准与风险评估国家重点实验室,北京100012

出　　处：《环境科学》2020年第1期57-64,共8页Environmental Science

基　　金：国家重点研发计划项目(2016YFC0208900);国家自然科学基金项目(41475116,41675127)

摘　　要：本研究于2011年7月至2012年5月期间采集了北京市春夏秋冬4个季节的PM2.5样品,使用电感耦合等离子质谱仪(ICP-MS)分析了样品中的总砷,并使用高压液相色谱(HPLC)和氢化物发生-原子荧光光谱法(HG-AFS)分析了样品中的As(Ⅲ)和As(Ⅴ).结果表明,在采样期间,北京市PM2.5中总As的平均浓度为(21. 82±17. 01) ng·m-3,总As在春夏秋冬春4个季节的平均浓度分别为(16. 62±5. 80)、(18. 34±9. 00)、(21. 49±10. 22)和(29. 52±27. 97) ng·m-3,呈现出冬季>秋季>夏季>春季的季节变化特征.PM2.5中As(Ⅲ)和As(Ⅴ)的平均浓度为(3. 15±1. 94) ng·m-3和(10. 78±5. 39) ng·m-3.春夏秋冬四季As(Ⅲ)的平均浓度分别是(5. 42±2. 5)、(1. 61±0. 51)、(2. 88±1. 12)和(3. 27±1. 23) ng·m-3,表现出春季>冬季>秋季>夏季的特征;不同季节As(Ⅴ)的平均浓度分别为夏[(13. 57±13. 34) ng·m-3]>秋[(12. 75±6. 54) ng·m-3]>冬[(8. 68±3. 57) ng·m-3]>春[(7. 55±1. 47) ng·m-3],不同季节PM2.5中As(Ⅲ)的平均浓度都高于As(Ⅴ),这种季节特征可能是由季节扩散条件、排放源和大气氧化性的差异等造成,As(Ⅲ)/As(Ⅴ)的季节变化也可以反映这些差异性,不同季节As(Ⅲ)与As(Ⅴ)的比值为春季(0. 67)>冬季(0. 44)>秋季(0. 27)>夏季(0. 13). As(Ⅲ)/As(Ⅴ)与相对湿度(Rh)呈现出一定的负相关性,表明高湿度条件可能不利于As(Ⅲ)转化成As(Ⅴ).As(Ⅲ)/As(Ⅴ)和As(Ⅲ)与Ca2+呈现出一定的正相关性,表明土壤扬尘可能是As(Ⅲ)的重要来源.This study assesses the chemical characteristics of As in aerosol PM2.5 samples that were collected from July 2011 to May2012 in Beijing,China. Total As,As( Ⅲ),and As( Ⅴ) were analyzed by inductively coupled plasma mass spectrometry( ICP-MS),high performance liquid chromatography( HPLC),and hydride generation atomic fluorescence( HG-AFS),respectively. The average concentrations of total As,As( Ⅲ) and As( Ⅴ) over the entire sampling period were( 21. 82 ± 17. 01),( 3. 15 ± 1. 94),and( 10. 78± 5. 39) ng·m-3,respectively. The average concentrations of total As,As( Ⅲ) and As( Ⅴ) were( 16. 62 ± 5. 80),( 18. 34 ±9. 00),( 21. 49 ± 10. 22),and( 29. 52 ± 27. 97) ng·m-3 during the spring,( 5. 42 ± 2. 5),( 1. 61 ± 0. 51),( 2. 88 ± 1. 12),and( 3. 27 ± 1. 23) ng·m-3 during the summer,and( 7. 55 ± 1. 47),( 13. 57 ± 13. 34),( 12. 75 ± 6. 54),and( 8. 68 ± 3. 57) ng·m-3 during the winter,respectively. The average concentrations of As( Ⅲ) in different seasons were higher than As( Ⅴ) concentrations.Seasonal characteristics may be caused by seasonal differences in diffusion conditions,emission sources,and atmospheric oxidation.The ratios of average concentrations of As( Ⅲ)/As( Ⅴ) were 0. 67 in spring,0. 13 in summer,0. 27 in autumn,and 0. 44 in winter.Ratios of As( Ⅲ)/As( Ⅴ) were negatively correlated with relative humidity,which indicates that high humidity conditions may not have been favorable for the transformation of As( Ⅲ) into As( Ⅴ) . As( Ⅲ)/As( Ⅴ) and As( Ⅲ) both showed positive correlations with Ca2 +,thereby indicating that soil dust may have been an important source of As( Ⅲ) .

关 键 词：北京市 PM2.5 AS As(Ⅴ) As(Ⅲ) 污染特征 

分 类 号：X513[环境科学与工程—环境工程]