杭州市大气降尘与PM10化学组成特征的研究

Chemical characteristics of atmospheric dustfall and PM_(10) in Hangzhou

2006年6月～2008年5月,在杭州市采集了大气降尘和PM10样品以及3类PM10源样品,对样品中12种无机元素进行了分析.结果表明,杭州市大气降尘量与PM10浓度相对于国内其他城市均属于较低水平,二者的季节变化存在明显差异;降尘量和PM10浓度的空间分布特征存在相似性,均与人类活动的强度密切相关.空间分布显示除PM10在朝晖和玉泉两采样点的成分谱相似,各采样点降尘和PM10成分谱间的相似性均不高.PM10与各源类成分谱的相似性高于降尘与各源类成分谱的相似性,二者来源的差异可能是造成降尘和PM10化学组分特征不同的原因,其中PM10与城市扬尘的化学成分相似性最高.

Samples of dustfall and PM10 as well as source samples of PM10 were collected from June 2006 to May 2008 at four monitoring stations of Hangzhou City.Twelve metals were quantified： chromium,manganese,nickel,lead,zinc,cobalt,aluminum,iron,potassium,sodium,calcium and magnesium.The deposited dust amount and concentration of PM10 was lower than most of the other cities in China.The dustfall and PM10 had different seasonal changing-mode.The similarity of spatial distribution implicated that both the amount of dustfall and concentration of PM10 were influenced by human activities.The chemical components of PM10 between Zhaohui and Yuquan were similar,whereas there was no high similarity between PM10 and dustfall in those sampling stations.Combined with the profiles of three PM10 sources,the similarity between PM10 and its sources was higher than that between dustfall and PM10 sources.It indicated that the dustfall and PM10 might come from different sources and it may cause the differences between the chemical characteristics of the dustfall and that of PM10.