兰州市大气降尘的化学特性  

Chemical characteristics of atmospheric dust in Lanzhou

作　　者：杨丽萍[1] 陈发虎[1] 张成君[1] 

机构地区：[1]兰州大学资源环境学院,甘肃兰州730000

出　　处：《兰州大学学报（自然科学版）》2002年第5期115-120,共6页Journal of Lanzhou University(Natural Sciences)

基　　金：国家自然科学基金资助项目 (497310 10 )

摘　　要：对定期收集的兰州市降尘样品 ,用 X射线荧光法分析了其中 2 4种元素的相对浓度 ,并用富集因子法对数据进行了处理、分析 ,结果表明兰州市现代降尘中主要有 Si O2 ,Al2 O3 ,Ca O,铁的氧化物 ,Mg O,Na2 O,K2 O,Ti O2 等 ,同时含有微量 P,Mn,Zn,Ba,Pb等元素 ;从元素浓度的年内变化情况看 ,Fe,Co,Cu,Cr,As等元素在采暖期 (11月～次年 3月 )浓度均高于非采暖期 ,Al,Si,Ca,Pb等元素浓度年内差异不大 ,而 Na,Mg,K等元素浓度在采暖期明显降低 ;在降尘中富集程度最高的元素 Zn,Pb,As主要来自人为污染 ,Si,Al,Mg,K,Na,V,Co,Ni则基本源于本地和邻近地区的土壤表土 ,Fe,Ca,Ti,P,Cu,Ba,Cr。samples of atmospheric dust were collected in Lanzhou City and analyzed for 24 elements by X-ray fluorescence.Enrichment factor was used in this study to identify different sources.SiO 2,Al 2O 3,CaO and Iron Oxides etc composed the major composition in the dust,while P,Mn,Zn,Ba etc were trace elements.According to the monthly variations of concentration,Fe,Cu,Co,Cr and As were higher during the heating period(Nov.to next Mar.).Na,Mg and K etc had an opposite pattern.The concentrations of Al,Si,Ca,Pb and some other elements showed no great changes within the whole year.Enrichment factor analyses indicated that anthropogenic sources were the major source of Zn,Pb,As and also contributes to Fe,Ca,Ti,P,Cu,Ba,Cr,Mn in a certain extent.On the contrary,elements such as Si,Al,Mg,K,Na,V,Co and Ni were generally from crustal soil.

关 键 词：兰州市 大气降尘 化学特性 元素组成 年内变化 高集因子 大气污染 

分 类 号：X131.1[环境科学与工程—环境科学]