摘要
通过采集北京有代表性的53个采样点的地面扬尘样品和典型区(交通区、工业区以及居民住宅区)3个采样点的气溶胶样品,分析研究了地面扬尘中主要元素和离子的浓度、空间分布、来源及其对大气颗粒物污染的贡献.结果表明,Ca、S、Cu、Zn、Ni、Pb和Cd是地面扬尘中的主要污染元素,Ca2+、SO42-、Cl-、K+、Na+和NO3-是地面扬尘中的主要离子.Al、Ti、Sc、Co和Mg主要来源于地壳源,Cu、Zn、Ni和Pb主要来源于交通排放和煤燃烧,Fe、Mn和Cd主要来源于工业排放、煤燃烧和油燃烧.Ca2+和SO42-主要来源于建筑活动、建筑材料和二次气粒转化,Cl-和Na+主要来源于工业废水处理和化学工业排放,NO3-和K+主要来源于机动车排放、NOx的光化学反应和生物质燃烧.北京地区矿物气溶胶的本地源,即地面扬尘,在不同季节的贡献量分别为2002年春季约30%,2002年夏季约70%,2003年秋季约80%,2002年冬季约20%.地面扬尘中一些主要元素Ca、S、Cu、Zn、Ni、Pb、Fe、Mn和Cd的污染水平分别为76%、87%、75%、80%、82%、90%、45%、51%和94%,它们对PM10中相应元素的贡献率分别为20%～45%、5%～18%、4%～50%、2%～46%、4%～52%、5%～20%、30%～60%、20%～40%和2%～25%.来自交通活动和建筑活动的地面扬尘是北京大气颗粒物污染的重要来源之一.
The re-suspended mad dust samples from 53 sites that could cover basically the entire Beijing in summer, and aerosol samples from three representative sites in Beijing in four seasons were collected to study concentrations and spatial variations of elements and ions in resuspended road dust and its contribution to the air-borne particulate pollution. Ca, S, Cu, Zn, Ni, Pb and Cd were main pollution elements, and Ca^2＋、SO4^2-、Cl^-、K^＋、Na^＋ and NO3^- were major ions in re-suspended road dust. AI, Ti, Sc, Co and Mg in re-suspended road dust were mainly originated from crustal source, while Cu, Zn, Ni and Pb were mainly originated from traffic emissions and coal burning, and Fe, Mn and Cd were mainly from industrial emissions and coal combustion. Ca^2 ＋ and SO4^2- mainly came from construction activities, construction materials and secondary gas-particle conversions, Cl^- and Na^＋ were derived from industrial wastewater disposal and chemical industrial emissions, and NO3^- and K^＋ were from vehicle emissions, photochemical reactions of NOx, biomass and vegetable burning. The contribution of mineral aerosol from inside Beijing to the total mineral aerosols was 30% in spring of 2002, 70% in summer of 2002, 80% in autumn of 2003, 20% in winter of 2002. The pollution levels of some major pollution species, Ca, S, Cu, Zn, Ni, Pb, Fe, Mn, and Cd in resuspended road dust reached 76%, 87%, 75%, 80%, 82%, 90%, 45%, 51%, and 94%, respectively, and their contributions to the related elements in PM10 were 20%-45%, 5%-18%, 4%-50%, 2%-46%, 4%-52%, 5%-20%, 30%-60%, 20%-40% and 2%- 25%. Re-suspended road dust from the traffic and construction activities is one of the major sources of the air-born particulate pollution in Beijing.
出处
《环境科学》
EI
CAS
CSCD
北大核心
2009年第1期1-8,共8页
Environmental Science
基金
国家重点基础研究发展规划(973)项目(2005CB724201,2006CB403704)
国家自然科学基金项目(50878006)
关键词
地面扬尘
理化特性
来源
矿物气溶胶
污染气溶胶
re-suspended road dust
characteristics
sources
mineral aerosol
pollution aerosol
