大气颗粒物酸碱性表征方法的研究

提出使用代表性酸碱组分定量表征大气颗粒物酸碱性的方法, 通过对颗粒物样品的水溶液进行微量酸碱滴定及其水溶性离子浓度测定, 利用酸碱平衡原理和溶液中离子 电荷守恒原理, 计算 出单位质量颗粒物中 6 种代表性酸碱组分的分析浓度, 能够量化颗粒物的酸碱性强弱和变化特征。将 1 mg 颗粒物加入到不同pH 值溶液中, 把计算得到的消耗氢离子的量与溶液的初始 pH 值进行多项式回归, 发现回归公式的相关系数均大于 0.99, 表明该多项式可以定量表征单位质量颗粒物对不同pH 降水的中和能力, 适用于估算较低离子浓度的降水捕获颗粒物后pH值的变化情况。

A Novel Method for Characterizing Acid-Base Properties of Atmospheric Particulate Matter

Six representative acid-base components are proposed to quantitatively characterize acid-base properties of particulate matter. Micro-titration and determination of water-soluble ion concentrations are applied to water-soluble particulate matter extract, then the acid-base balance principle and the principle of charge conservation are adopted to calculate the concentrations of representative components. Polynomial regression is conducted to analyze the relationship between the amounts of hydrogen ions neutralized by particulate matter of unit mass and the initial pH values of absorption solutions, and a series of empirical equations are obtained, which are applicable to estimate the change in pH derived by the particles absorbed by the precipitation with lower ion concentrations.