PM2.5浓度变化、化学组成及来源研究

Study on PM2.5 Concentration Change Chemical Composition and Source

此次研究利用化学重构以及PMF模型,提出了基于PMF的PM2.5化学成分与源解析方法,该方法能够通过质量重构,精准分析PM2.5的化学成分以及来源。以北京市的大气数据作为样本,并将其分为市区、郊区以及城市背景区三个对照组,对该方法进行验证。验证结果显示,大气颗粒物主要由含炭物质、二次水溶性无机离子、矿物尘、痕量元素以及氯离子组成。其中的含碳物质、二次水溶性无机离子以及痕量元素的年均质量浓度最高的地区为市区;而矿物尘的年均质量浓度则以郊区为甚;三个区域的氯离子的年均质量浓度基本相近。另外,三区的源解析结果表明,PM2.5的主要来源为二次无机气溶胶、燃煤、地区浮沉、生物质燃烧、工业、城市扬土、燃油以及机动车尾气。本研究可以为PM2.5化学组成与源解析提供一定的指导价值。

In this paper,the chemical composition and source analysis method of PM2.5 based on the chemical re⁃construction and PMF model is proposed,which can accurately analyze the chemical composition and source of PM2.5 through the quality reconstruction.The air data of Beijing were taken as samples and divided into three con⁃trol groups:urban area,suburban area and urban background area.The results show that atmospheric particles are mainly composed of carbonaceous materials,secondary water-soluble inorganic ions,mineral dust,trace elements and chloride ions.Among them,the area with the highest annual mass concentration of carbonaceous substances,secondary water-soluble inorganic ions and trace elements is the urban area,while the annual average mass con⁃centration of mineral dust is even higher in the suburbs;the annual mass concentration of chloride ions in the three areas is basically similar.In addition,the source analysis results of the three regions show that the main sources of PM2.5 are secondary inorganic aerosol,coal combustion,regional ups and downs,biomass combustion,industry,ur⁃ban soil lifting,fuel oil and vehicle exhaust.This paper can provide some guidance value for the chemical composi⁃tion and source analysis of PM2.5.