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Acid Particle Formation and Their Effects on Acidification of Rain

酸性颗粒的形成及其对雨水酸化的影响

基本信息

批准号：
05452399
负责人：
KASAHARA Mikio
金额：
$ 4.03万
依托单位：
KYOTO UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1993
资助国家：
日本
起止时间：
1993 至 1994
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-05452399/
关键词：
Sulfur dioxide Acid particles Gas-to-particle conversion Rain water Atmospheric aerosols Wet scavenging PIXE analysis Ion chromatography DMS 粒子沈着イオンクロマト分析

项目摘要

The following three research subjects were investigated in this study.1) Formation of sulfuric acid particles from SO_2 gas and its conversion rate :The gas-to-particle conversion of SO_2 to sulfuric acid particles was investigated using a flow-type smog chamber. The total number concentration and the particle size distribution were measured. The amount of sulfur particles collected onto the Nuclepore filter was determined by PIXE analysis to estimate the conversion rate. Aerosol particle formation from DMS (Dimethyl sulfide) was also investigated. The conversion rates of SO_2 and DMS to particles were estimated to be order of 10^<-2> and 10^<-4>h^<-1>, respectively.2) Scavenging of atmospheric aerosols by rain water :Rain drops were collected every0.1mm rainfall from the beginning of rain. Rain water was divided into the soluble and insoluble components by passing through a 0.2mum pore-size filter. Ion concentration in solbule components was measured by ion-chromatography. The elemental concentrations in both components were determined by PIXE analysis. Elemental concentrations of atmospheric aerosols sampled before and during the rain were also measured by PIXE analysis. Almost all of S and Cl were dissolved in rain water. Fe, Ti and Si which originate mainly in soil source were scavenged in insoluble state.3) Modeling of wet scavenging of aerosol particles :A numerical model simulating the wet scavenging of aerosol particles was developed. The effects of particle size distribution and the rain intensity on the washout of aerosol particle were investigated. Elements of Fe, Ti and Si are contained mainly in the coarse particles with the size larger than 1.0mum and are scavenged effectively. On the other hand, S and Pb consisting mainly of the fine particles are not easily washed out.A five-layr Lagrangian model taking into consideration of the SO_2-to-SO_4^<2-> conversion and dry and wet deposition of SO_2 and SO_4^<2-> was also developed.

本研究主要研究了以下三个方面的内容：1)SO2气体中硫酸颗粒的形成及其转化率：利用流动烟雾室研究了SO2气相转化为硫酸颗粒的过程。测定了颗粒的总浓度和粒径分布。通过PIXE分析确定核孔过滤器上收集的硫磺颗粒的数量，以估计转化率。还研究了DMS(二甲基硫化物)气溶胶粒子的形成。SO_2和DMS向颗粒物的转化速率分别为10^~(-2)和10^~(-4)数量级。2)雨水对大气气溶胶的清除作用：从降雨开始每0.1 mm雨量收集一次雨滴。雨水通过0.2微米孔径的过滤器被分成可溶组分和不溶组分。采用离子色谱法测定药丸成分中的离子浓度。用PIXE分析测定了两组分中的元素浓度。降雨前和降雨期间采集的大气气溶胶元素浓度也通过PIXE分析进行了测量。S和氯离子几乎全部溶于雨水中。主要来源于土壤源的Fe、Ti和Si在不溶状态下被清除。3)气溶胶颗粒湿法清除模型：建立了气溶胶颗粒湿法清除的数值模型。研究了粒子的粒度分布和降雨强度对气溶胶粒子洗出的影响。铁、钛、硅元素主要存在于粒径大于1.0微米的粗颗粒中，被有效地清除。另一方面，以细颗粒为主的S和铅不易被冲刷掉。本文还建立了一个五层拉格朗日模型，该模型考虑了SO2到SO4的转化和SO2和SO4的干湿沉降。