成都市冬季大气PM_(2.5)的化学组成及对能见度的影响  

Chemical composition of PM_(2.5) and its impact on visibility at Chengdu in 2010 winter

作　　者：王启元[1,2] 陶俊[3] 任鹏奎[4] 沈振兴[1] 罗磊[5] 唐信英[5] 

机构地区：[1]西安交通大学环境科学与工程系,西安710049 [2]中国科学院地球环境研究所黄土与第四纪地质国家重点实验室,西安710075 [3]环境保护部华南环境科学研究所,广州510655 [4]青海省地质调查院,西宁810012 [5]中国气象局成都高原气象研究所,成都610071

出　　处：《地球环境学报》2012年第5期1104-1108,共5页Journal of Earth Environment

基　　金：中国科学院战略性先导科技专项(XDA05100401);国家公益项目(201209007)

摘　　要：为研究成都市PM_(2.5)的化学成分及其对能见度的影响,于2010年1月采集大气中PM_(2.5)样品。通过实验分析了PM_(2.5)中水溶性离子(Cl^-、NO_3^-、SO_4^(2-)、NH_4^+、K^+、Na^(2+)、Ca^(2+)及Mg^(2+))和含碳物质(有机碳OC和元素碳EC)的污染水平,探讨了它们对能见度的影响。结果表明,水溶性离子、OC和EC是PM_(2.5)的主要成分,分别占PM_(2.5)质量浓度的50.7%、14.0%和5.1%。PM2.5质量浓度与能见度呈指数相关,二次无机离子(NH_4^+、SO_4^(2-)和NO_3^-)与能见度呈较好的负相关。PM_(2.5)浓度的增加,尤其是二次无机离子浓度的增加是导致能见度降低的主要因素。(NH_4)_2SO_4对消光系数贡献最大,占总消光系数的44.6%,其次是NH_4NO_3和OM,贡献率分别为27.4%和18.5%。The object of this study was to investigate the chemical composition of PM2.5 and its influence on visibility during winter in Chengdu. PM2.s samples were collected daily at the Institute of Plateau Meteorology. Water-soluble ionic species （EI-, NO3, SO2＋4, NH4, K＋, Na＋, Ca2＋, and Mg2＋） and carbonaceous contents （OC and EC ） of the PM2.5 samples were analyzed to characterize their impact on visibility impairment. The results showed that water-soluble ionic, OC, and EC were the major species in PM2.5, which contributed 50. 7%, 14. 0% and 5. 1% to PM2.5 concentrations and visibility appeared an exponential mass, respectively. The relationship between PM2.5 correlation; and secondary inorganic ions （NH4＋, SOl and NO3- ） shows strongly positive with visibility. The increased concentrations of PM2.5 and secondary inorganic ions were the main causes leading to low visibility. （NH4） 2S04 had the largest contribution to light extinction coefficient accounting for 44.6%, followed by NH4NO3 （27.4%） and OM （18.5%）.

关 键 词：PM2. 5 水溶性离子 含碳物质 能见度 

分 类 号：X513[环境科学与工程—环境工程]