摘要
为了揭示桂林市大气中PM_(2.5)组分特征,本研究于2015年秋季在桂林5个环境受体点采集了PM_(2.5)样品,分析了PM_(2.5)质量浓度及多种无机元素、水溶性离子和有机碳(OC)、元素碳(EC)的含量,并运用富集因子法、比值法等分别研究了PM_(2.5)中元素富集程度、颗粒物来源等情况,并探讨了PM_(2.5)中高硫酸盐(SO_4^(2-))的污染成因.结果表明,采样期间,桂林市PM_(2.5)的浓度为(57.0±35.8)μg·m-3,PM_(2.5)中以水溶性离子(56.7%)和有机物OM(22.6%)污染最为突出,其次是元素(7.2%)和EC(6.3%).PM_(2.5)中Se、Pb、As、Zn、V、Cu严重富集,表明燃煤源排放对桂林市大气中元素产生了较大的影响;[NO_3^-]/[SO_4^(2-)]比值小于1,也进一步证明了固定燃烧源的主导作用.SO_4^(2-)/PM_(2.5)的比值为41%,高于国内其他城市报道值;而SOR均值0.51远高于一次排放源特征值(0.1),表明除本地和区域传输的一次SO_4^(2-)排放外,SO_4^(2-)主要来自SO_2的二次转化.因此,桂林市在控制本地燃煤源排放的同时,还应当注意区域污染传输对PM_(2.5)的影响.
To investigate the composition of PM_（2.5）,samples were collected at 5 sites from September2015 to November 2015 in Guilin.Concentrations of PM_（2.5）,inorganic elements,water-soluble ions,organic carbon（OC） and elemental carbon（EC） were analyzed.Enrichment factor method and ratioing were used to evaluate the element enrichment degree and the source of PM_（2.5）,as well as to investigate the reason for the pollution of high-concentration secondary sulfate in PM_（2.5）.The results showed that the concentration of PM_（2.5） was（57.0±35.8） μg·m^（-3）,among which the concentrations of water-soluble ions and OM,which contributed the most to the spotted pollution,were 56.7% and22.6%,respectively,followed by trace element（7.2%） and EC（6.3%）.Se,Pb,As,Zn,V and Cu were mainly enriched by anthropogenic pollution,such as coal-burning activities.The ratio of[NO_3^-]/[SO_4^（2-）]was less than 1,indicating the dominant role of fixed combustion source.The ratio of [SO_4^（2-）]/PM_（2.5） was 41%,higher than reported values in other cities in China,and the average value of SOR was well above the flag value of first emission（0.1）.This means that in addition toemission of SO_4^（2-） from local coal-fired source and regional transmission,most sulfate was from secondary transformation process.Therefore,the effects of regional pollution transmission on PM_（2.5） should be noted at the same time as emissions from the local coal sources were concerned in Guilin.
出处
《环境化学》
CAS
CSCD
北大核心
2017年第12期2676-2682,共7页
Environmental Chemistry
基金
国家自然科学基金(21577090)
桂林市2015年节能减排资金资助~~
关键词
桂林
PM2
5
组分特征
高浓度硫酸根
形成机制
Guilin, PM2.5 , composition characteristics, high concentration sulfate, formationmechanism.
