Water-soluble matter in PM_(2.5)in a coastal city over China:Chemical components,optical properties,and source analysis

作     者：Yanan Zhan Narcisse T.Tsona Jianlong Li Qingcai Chen Lin Du Yanan Zhan;Narcisse T.Tsona;Jianlong Li;Qingcai Chen;Lin Du

作者机构：Environment Research InstituteShandong UniversityQingdao 266237China School of Environmental Science and EngineeringShaanxi University of Science and TechnologyXi’an 710021China 

出 版 物：《Journal of Environmental Sciences》 (环境科学学报（英文版）)

年 卷 期：2022年第34卷第4期

页      面：21-36页

核心收录：

学科分类：07[理学] 0707[理学-海洋科学] 070602[理学-大气物理学与大气环境] 0804[工学-仪器科学与技术] 0706[理学-大气科学] 0703[理学-化学] 

基　　金：supported by the National Natural Science Foundation of China(Nos.22076099,21876098,41877354) Youth Innovation Program of Universities in Shandong Province(No.2019KJD007) Fundamental Research Fund of Shandong University(No.2020QNQT012) 

主　　题：Excitation-emission matrix spectroscopy Chemical components Optical properties PM_(2.5) Coastal city 

摘      要：Although marine and terrestrial emissions simultaneously affect the formation of atmospheric fine particles in coastal areas,knowledge on the optical properties and sources of water-soluble matter in these areas is still scarce.In this work,taking Qingdao,China as a typical coastal location,the chemical composition of PM_(2.5)duringwinter 2019was analyzed.Excitation-emission matrix fluorescence spectroscopy was combined with parallel factor analysis model to explain the components of water-soluble atmospheric chromophores of PM_(2.5).Our analysis indicated that NO_(3)^(-),NH_(4)^(+)and SO_(4)^(2-)ions accounted for 86.80%of the total ion mass,dominated by NO_(3)^(-).The ratio of[NO_(3)^(-)]/[SO_(4)^(2-)]was up to 2.42±0.84,suggesting thatmobile sources play an important role in local pollutants emission.The result of positive correlation between Abs_(365)with K^(+)suggests that biomass burning is an important source of water-soluble organic compounds(WSOC).Six types of fluorophores(C1-C6),all humic-like substances,were identified in WSOC.Humification index,biological index and fluorescence index in winter were 1.66±0.34,0.51±0.44 and 1.09±0.78,respectively,indicating that WSOC in Qingdao were mainly terrestrial organic matters.Overall,although the study area is close to the ocean,the contribution of terrestrial sources to PM_(2.5),especially vehicle exhaust and coal combustion,is still much higher than that of marine sources.Our study provides a more comprehensive understanding of chemical and optical properties of WSOC based on PM_(2.5)in coastal areas,and may provide ground for improving local air quality.