摘要
大气细颗粒物(PM2.5)对气候变化和人体健康具有重要影响。PM2.5中的元素碳(EC)在大气中不发生反应,所以其来源变化可以指示PM2.5一次燃烧源的变化。本文结合放射性碳同位素(14C)和稳定碳同位素(13C)方法,分析了西安2008/2009年和2015/2016年冬季PM2.5中EC的同位素组成。14 C的分析结果表明,西安冬季EC的主要来源为化石燃料燃烧,2008/2009年和2015/2016年化石燃料燃烧对EC的贡献分别为77%±4%和72%±5%。13C的分析结果表明,2015/2016年西安冬季EC排放源主要来自液体化石燃料燃烧(机动车排放)(δ13 CEC:-25.04‰^-24.64‰,-24.80‰±0.21‰),而2008/2009年冬季燃煤对EC的贡献更为显著(δ13 CEC:-23.72‰^-22.81‰,-23.22‰±0.39‰)。对比14 C和13 C的数据发现,近十年西安冬季EC排放源的变化显著,燃煤的相对贡献降低,而机动车排放的贡献升高,这与煤改气和机动车保有量的急速增加有关。
Fine particulate matter(PM2.5)play an important role in climate and human health.The element carbon(EC)in PM2.5 doesn’t react in atmosphere,so its sources can indicate the change of primary combustion sources.This work aims to identify the sources of EC in winter of Xi’an in 2008/2009 and 2015/2016 by combining the method of stable carbon isotope(13 C)and radioactive carbon isotope(14 C).The 14 C results demonstrate that EC was dominated by fossil sources in 2008/2009 and 2015/2016,with a mean contribution of 77%±4%and 72%±5%.13 C composition of EC was more enriched in 2008/2009(-23.72‰^-22.81‰,-23.22‰±0.39‰)compared to that in 2015/2016(-25.04‰^-24.64‰,-24.80‰±0.21‰),indicating the influence of coal combustion in 2008/2009 and liquid fossil fuel combustion in 2015/2016.By combining 14 C and 13 C signatures,the change of EC emission sources was significant of Xi’an in the past decade,it was found that the relative contributions from coal combustion to EC decreased,and vehicle emission to EC increased respectively.This is related to the change of coal to gas and the rapid increase of motor vehicles population.
作者
黄汝锦
郭洁
倪海燕
曹军骥
HUANG Ru-jin;GUO Jie;NI Hai-yan;CAO Jun-ji(State Key Laboratory of Loess and Quaternary Geology,Institute of Earth Environment,Chinese Academy of Sciences,Xi’an 710061,China;Key Laboratory of Aerosol Chemistry&Physics,Institute of Earth Environment,Chinese Academy of Sciences,Xi’an 710061,China;CAS Center for Excellence in Quaternary Science and Global Change,Xi'an 710061,China)
出处
《矿物岩石地球化学通报》
CAS
CSCD
北大核心
2019年第6期1073-1080,I0001,共9页
Bulletin of Mineralogy, Petrology and Geochemistry
基金
国家重点研发计划项目(2017YFC0212701)。
