生态环境学报 ›› 2023, Vol. 32 ›› Issue (3): 545-555.DOI: 10.16258/j.cnki.1674-5906.2023.03.012

• 研究论文 • 上一篇    下一篇

济南市城市扬尘的微观形貌和化学组分特征分析

张怀成1(), 韩红2, 王在峰1, 韩立钊3, 刘克4, 张桂芹2, 范晶2, 魏小锋2,*()   

  1. 1.山东省济南生态环境监测中心,山东 济南 250100
    2.山东建筑大学市政与环境工程学院,山东 济南 250101
    3.济南市生态环境局槐荫分局,山东 济南 250117
    4.山东碧轩环境检测有限公司,山东 济南 250013
  • 收稿日期:2022-09-21 出版日期:2023-03-18 发布日期:2023-06-02
  • 通讯作者: *魏小锋,女,讲师,博士,主要研究方向为大气环境化学。E-mail:weixf@sdjzu.edu.cn
    *魏小锋,女,讲师,博士,主要研究方向为大气环境化学。E-mail:weixf@sdjzu.edu.cn
  • 作者简介:张怀成(1963年生),男,研究员,主要研究方向为环境监测。E-mail: qzhang1993@163.com
  • 基金资助:
    济南市高校创新团队项目(2020GXRC008);济南市政府颗粒物来源解析采购项目(37000000040201520210016_001)

Micromorphology Characteristics and Chemical Composition of Urban Dust in Ji'nan

ZHANG Huaicheng1(), HAN Hong2, WANG Zaifeng1, HAN Lizhao3, LIU Ke4, ZHANG Guiqin2, FAN Jing2, WEI Xiaofeng2,*()   

  1. 1. Shandong Provincial Environmental Monitoring Center, Ji'nan 250101, P. R. China
    2. School of Municipal and Environmental Engineering, Shandong Jianzhu University, Ji'nan 250101, P. R. China
    3. Ji'nan Ecological Environment Bureau Huaiyin Branch, Ji'nan 250101, P. R. China
    4. Shandong Bixuan Environmental Testing Co., Ltd, Ji'nan 250101, P. R. China
  • Received:2022-09-21 Online:2023-03-18 Published:2023-06-02

摘要:

城市扬尘作为大气颗粒物的主要来源之一,对环境空气质量的影响较大。为探究济南市不同区域城市扬尘物理特性、微观形貌和化学组分的季节变化特征,采集了济南市有代表性的四个区域(钢铁集聚区、城郊结合部、市区和县区)2021年不同季节的扬尘样品,分析了扬尘的比表面积、微观形貌、化学组分的变化特征。结果表明,春季扬尘颗粒粒径较小,比表面积较大;钢铁集聚区PM2.5占比最高,为5.26%,比表面积为351.3 m2·kg-1;其次为市区PM2.5占比较高,为3.49%,比表面积为247.5 m2·kg-1。扫描电镜结果显示钢铁集聚区和市区扬尘颗粒主要有规则的“块状”“簇状”“片状”的矿物颗粒、不规则的“链状”和“蓬松状”的烟尘集合体以及“球状”燃煤飞灰颗粒,钢铁集聚区链状密集的烟尘集合体主要来源于机动车尾气和燃煤,市区聚合蓬松状烟尘集合体主要来源于机动车尾气;春季矿物颗粒比例较大,冬季密集链状烟尘集合体和燃煤飞灰较多,主要来源于机动车尾气和燃煤,其他季节聚合蓬松状烟尘集合体较多,主要来源于机动车尾气。各区域扬尘PM2.5中水溶性离子Ca2+、SO42-和Na+含量较高。4个区域中各季节AE/CE值均小于1,说明济南市扬尘PM2.5呈碱性,市区冬季的AE/CE最高为0.36。扬尘PM2.5中碳组分均以OC为主,济南市各区域扬尘中OC/EC比值在5.4-17.5之间,均存在明显的二次有机碳的生成,且碳组分主要来自于燃煤和生物质燃烧排放。扬尘PM2.5中金属元素Si、Al和Fe含量较高,主要受土壤风沙、燃煤和钢铁冶炼影响。

关键词: 城市扬尘, 季节变化, 比表面积, 形貌特征, 碳组分, 金属元素

Abstract:

Ji'nan, the economic, political and cultural center of Shandong Province, is one of the “2+26” cities in the Beijing-Tianjin-Hebei air pollution transmission channel. Urban dust is one of main sources of atmospheric particulate matters and influences ambient air quality greatly. The dust samples in different seasons in 2021 from four representative regions of Jinan (steel agglomeration area, suburban junction, urban area and county area) were collected to explore the seasonal variation characteristics of urban dust. Specific surface area, microscopic morphology and chemical composition of the dust were analyzed and the results showed that the particle size of dust in spring was smaller and the specific surface area was larger. The dust from steel agglomeration area had the highest PM2.5 ratio (5.26%) and specific surface area (351.3 m2·kg-1). PM2.5 in urban area accounted for 3.49%, and that in the specific surface area was 247.5 m2·kg-1. Scanning electron microscopy results showed that the dust in the steel agglomeration area consisted of mainly regular “block-like”, “cluster-like”, “flaky” mineral particles, irregular "chain-shaped" and “fluffy” soot aggregates, and “spherical” coal-fired fly ash particles. In this area, the dense chain soot aggregates mainly came from motor vehicle exhaust and coal burning, while the aggregates in the urban area almost only came from motor vehicle exhaust. In spring, the proportion of mineral particles was large. In winter, dense chain soot aggregates and coal-burning fly ash dominated and mainly came from motor vehicle exhaust and coal-burning. There were more aggregated fluffy soot aggregates in other seasons. The contents of water-soluble ions Ca2+, SO42- and Na+ in PM2.5 of dust in various regions were high. In the four regions, the AE/CE values in each season were less than 1, indicating that the PM2.5 of dust in Jinan was alkaline, especially the winter AE/CE in the urban was no more than 0.36. The carbon components in the PM2.5 of dust were mainly OC. The ratio of OC/EC in the dust of Jinan was between 5.35-17.47 with highly possible secondary organic carbon generation occurring. The carbon components mainly came from coal combustion and biomass combustion emissions. The metal elements, Si, Al, and Fe content, in the PM2.5 of dust were higher, indicating that it was mainly affected by soil, wind, sand, coal burning and steel smelting.

Key words: urban dust, seasonal variation, specific surface area, morphological characteristics, carbon fraction, metallic element

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