Although marine and terrestrial emissions simultaneously affect the formation of atmo-spheric 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 PPM2.5 during winter 2019 was analyzed.Excitation-emission matrix fluorescence spectroscopy was combined with parallel factor analysis model to explain the components of water-soluble atmospheric chromophores of PM2.5.Our analysis indicated that NO3-,NH4+and SO42-ions accounted for 86.80％of the total ion mass,dominated by NO3-.The ratio of[NO3-]/[SO42-]was up to 2.42±0.84,sug-gesting that mobile sources play an important role in local pollutants emission.The result of positive correlation between Abs365 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,indi-cating 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 PM2.5,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 PM2.5 in coastal areas,and may provide ground for improving local air quality.

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

Environment Research Institute,Shandong University,Qingdao 266237,China;School of Environmental Science and Engineering,Shaanxi University of Science and Technology,Xi'an 710021,China

环境科学学报（英文版）

[1]Yanan Zhan;Narcisse T.Tsona;Jianlong Li;Qingcai Chen;Lin Du-.Water-soluble matter in PM2.5 in a coastal city over China:Chemical components,optical properties,and source analysis)[J].环境科学学报（英文版）,2022(04):21-36

PPM2,NH4+and,Abs365,K+suggests,Humification

Water,soluble,coastal,city,over,China,Chemical,components,optical,properties,analysis,Although,marine,terrestrial,emissions,simultaneously,affect,formation,fine,particles,areas,knowledge,sources,water,these,still,scarce,In,this,work,taking,Qingdao,typical,location,chemical,composition,during,winter,was,analyzed,Excitation,matrix,fluorescence,spectroscopy,combined,parallel,model,explain,atmospheric,chromophores,Our,indicated,that,NO3,SO42,accounted,total,dominated,by,ratio,up,gesting,mobile,play,important,role,local,pollutants,result,positive,correlation,between,biomass,burning,organic,compounds,WSOC,Six,types,fluorophores,C1,C6,humic,like,substances,were,identified,biological,respectively,cating,mainly,matters,Overall,although,study,close,ocean,contribution,especially,vehicle,exhaust,coal,combustion,much,higher,than,provides,more,comprehensive,understanding,may,ground,improving,air,quality

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