Ecology and Environment ›› 2021, Vol. 30 ›› Issue (7): 1420-1427.DOI: 10.16258/j.cnki.1674-5906.2021.07.011

• Research Articles • Previous Articles     Next Articles

Pollution Characteristics and Sources of Carbonaceous Components in PM2.5 during Winter in Chengdu

SHI Huibin1(), HUANG Yi2,*(), CHENG Xin2, LI Ting1, HE Min1, WANG Jinjin1   

  1. 1. College of Earth Sciences, Chengdu University of Technology, Chengdu 610059, China
    2. College of Ecology and Environment, Chengdu University of Technology, Chengdu 610059, China
  • Received:2021-04-28 Online:2021-07-18 Published:2021-10-09
  • Contact: HUANG Yi

成都市冬季PM2.5中碳组分污染特征及来源解析

石慧斌1(), 黄艺2,*(), 程馨2, 李婷1, 何敏1, 王进进1   

  1. 1.成都理工大学地球科学学院,四川 成都 610059
    2.成都理工大学生态环境学院,四川 成都 610059
  • 通讯作者: 黄艺
  • 作者简介:石慧斌(1998年生),男,硕士研究生,主要研究方向为环境地球化学。E-mail: 1482003163@qq.com
  • 基金资助:
    国家重点研发计划项目(2018YFC0214001);四川省科技支撑计划项目(21CXTD0015)

Abstract:

The characteristics and sources of carbonaceous components in PM2.5 were studied in Chengdu area during a winter haze period. Samples of PM2.5 were collected from December 7, 2019 to December 28, 2019 in Chengdu, and mass concentrations of organic carbon (OC), elemental carbon (EC) and isotopic compositions of carbon were determined using a thermal/optical carbon analyzer and elemental analyzer-isotopic mass spectrometer. The average mass concentrations of PM2.5, OC and EC were 98.23, 14.50, 2.19 μg∙m-3. OC was strongly correlated with EC in Chengdu (correlation coefficient=0.80), which indicated that OC and EC had either similar sources or a high mixing degree. The OC/EC ratio exceeded 2.0, which further indicated the formation of secondary organic carbon (SOC), yielding a SOC value of 34.48% of total organic carbon. Principal component analysis (PCA) of carbonaceous components in PM2.5 indicated two overall sources. A mixed source derived from biomass combustion, coal burning and gasoline vehicle exhaust dust was the major source, contributing 59.68% overall in Chengdu area. Diesel vehicle exhaust dust was the minor source, contributing 22.40%. The results of carbon isotope composition showed that the source of carbon components in PM2.5 was mostly related to the exhaust dust of gasoline vehicles, followed by C3 plant combustion during winter in Chengdu. Results from modeling software IsoSource, showed the following component relations: exhaust dust of gasoline vehicles>C3 plant combustion>diesel vehicle exhaust dust>Coal burning>C4 plant combustion>natural geological sources. Compared to low PM2.5 clean periods, the exhaust dust of gasoline vehicles and C3 plant combustion accounted for a larger proportion during the haze period. These research results will help to develop effective air pollution control measures in Chengdu.

Key words: organic carbon (OC), elemental carbon (EC), secondary organic carbon (SOC), source analysis, carbon isotope

摘要:

为研究成都市冬季PM2.5中碳组分的污染特征和来源,于2019年12月7—28日在成都市进行PM2.5的采集,并利用热光碳分析仪和元素分析仪-同位素质谱仪分别测定了样品中有机碳(OC)和元素碳(EC)的质量浓度以及碳同位素的组成特征。结果表明,成都市PM2.5、OC和EC的平均质量浓度分别为98.23、14.50、2.19 μg∙m-3;OC和EC的相关性较高(相关系数为0.80),表明OC和EC可能具有一致的来源,也有可能是具有较高的混合程度;OC/EC比值大于2.0,表明成都市冬季有二次有机碳(SOC)的形成,且SOC/OC的比值为34.48%;主成分分析结果显示,生物质燃烧、燃煤和汽油车尾气尘混合源是成都市冬季PM2.5碳组分的主要来源,贡献率为59.68%;其次是柴油车尾气尘,贡献率为22.40%;碳同位素组成结果显示,成都市冬季PM2.5碳组分的来源与汽油车尾气排放相关性最强,其次为C3植物燃烧;通过IsoSource模型软件进行计算,可知不同时期各污染源的贡献比例均呈现出汽油车尾气排放>C3植物燃烧>柴油车尾气排放>燃煤>C4植物燃烧>地质源(农业土壤、扬尘)的规律,但相较于清洁期来说,污染期的汽油车尾气排放和C3植物燃烧污染源所占比例增大。研究结果可为成都市大气污染治理提供理论指导。

关键词: 有机碳, 元素碳, 二次有机碳, 来源解析, 碳同位素

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