生物质燃烧颗粒物的定量分析和化学形态  

QUANTITATIVE ANALYSIS AND CHEMICAL SPECIATION OF BIOMASS BURNING PARTICLES

作　　者：刘咸德[1] 李玉武[1] 董树屏[1] Van EspenP Adams F Maenhaut W 

机构地区：[1]国家环境分析测试中心,北京100029 [2]比利时Antwerp大学化学系 [3]比利时Gent大学核科学研究所

出　　处：《环境化学》2002年第3期200-217,共18页Environmental Chemistry

基　　金：国家自然科学基金 ( 2 97770 2 9;2 0 1 770 36 );中-比(弗拉芒)双边科技合作(BWTS 97/71 )资助项目

摘　　要：用电子探针技术开展单个含钾颗粒物的分析表征 .第一种方法用蒙特卡洛方法模拟电子束与样品复杂的相互作用 ,对于KCl晶粒取得的计算结果与理论值一致 .K/Cl比的均值为 0 996 ,标准偏差为 0 0 1 2 .由于晶形不规则和热稳定性差 ,K2 SO4 和KHSO4 的结果没有达到KCl的准确度 .其K/S比的均值和标准偏差分别为 1 90 5±0 0 1 3和 1 0 1 4± 0 0 72 .第二种方法用回归分析方法处理了同一种类若干数目的颗粒物分析数据 .直接用同种类标准颗粒物的分析结果校准 ,进行定量分析和化学形态识别 .研究结果表明 ,非洲草原大火燃烧排放时 ,含钾颗粒经历了逐步酸化的过程 .在排放时主要以KCl形态存在 ,少量是K2 SO4 和复盐 .在大气传输过程中逐渐酸化 ,主要转变成KHSO4 .少量停空时间长的颗粒则继续酸化 ,成为高度富硫的颗粒 .Major particle classes of biomass burning emission,the potassium-containing particles were analyzed individually with electron probe microanalysis(EPMA)technique.Two approaches were used for the quantitative analysis and chemical speciation identification.The first approach is the Monte Carlo simulation approach.It simulates the complex interaction between electron beam and the specimen,and successfully formulate and express the matrix and size effects in single particle quantitative analysis.The results of KCl crystal with micrometer sizes are in good agreement with theoretical value.The average K/Cl atomic ratio is 0.996 with standard deviation of 0.012.The results of K 2SO 4 and KHSO 4 are less good,the average K/S atomic ratio and standard deviation are 1.905±0.013 and 1.014±0.072,respectively.The second approach is suitable for the sub-micrometer particles.For quantitative analysis and identification of chemical speciation,the regression analysis was carried out for the data of a number of particles,and calibration was done with laboratory standard particles with similar composition.In this study it was illustrated that potassium-containing particles emitted by biomass burning,underwent gradual acidification in the atmosphere.When emitted,it existed mainly as KCl and a small portion as K 2SO 4 or composite salt of both.During atmospheric transport it got more and more acidified.Most of the potassium containing particles converted to chemical forms similar to KHSO 4.For those fine particles that happened to stay longer in air,became very much enriched in sulfates either as ammonium sulfate or sulfuric acid.

关 键 词：生物质燃烧 颗粒物 定量分析 化学形态 

分 类 号：O643.2[理学—物理化学]