生态环境学报2024，Vol.33Issue(7)：1072-1078,7.DOI:10.16258/j.cnki.1674-5906.2024.07.008
PM2.5中水溶性有机碳的污染特征、吸光特性和来源研究
Pollution Characteristics,Light Absorption and Sources of Water-soluble Organic Carbon in PM2.5
摘要
Abstract
Water-soluble organic carbon(WSOC)in atmospheric particulate matter(PM)is an important component of carbonaceous aerosols that has a significant impact on regional climate change and human health owing to its light absorption,hygroscopic properties,and toxic components.In Zhengzhou,a megacity with heavy PM pollution,there is a lack of short-and long-term studies on WSOC.To investigate the pollution characteristics,seasonal variation,sources,and light absorption of water-soluble organic carbon(WSOC)in PM2.5,seasonal PM2.5 samples were collected from December 2020 to October 2021.The concentration(using a total organic carbon analyzer)and light absorption parameters(UV-visible spectrophotometer)of WSOC were analyzed,and water-soluble inorganic ions(ion chromatography),organic carbon(OC),and elemental carbon(EC)(thermo-reflective carbon analyzer)were combined to identify the sources of WSOC.The results showed that the WSOC concentration averaged(13.56±7.48)μg∙m-3 during the sampling periods and exhibited significant seasonal variations,with the maximum value in winter and the minimum value in summer.Compared to domestic and foreign studies,WSOC pollution in this study was more serious,and its impact on human health and uncertainty in assessing and predicting climate impacts cannot be ignored.The contribution of WSOC to OC was significantly higher in summer than in winter,indicating the significant influence of secondary generations in summer.The major WSOC sources identified by the positive matrix factorization(PMF)model and correlation analysis were biomass burning,secondary generation,and vehicle exhaust emissions,followed by coal burning and soil/construction dust sources.The annual average light absorption index(AAE)was 6.88±1.31,with no significant seasonal variations.The annual average light absorption intensity(Abs365)was(9.71±5.77)Mm-1.Correlation analysis showed that water-soluble brown carbon(BrC)and WSOC had similar sources during the sampling period,with biomass burning in winter and secondary-generation burning in summer being the main sources.The annual average mass absorption efficiency(MAE365)was(0.710±0.206)m2∙g-1,which is a moderate level compared to domestic and foreign studies,and the influence of the WSOC mass unit on radiative forcing in Zhengzhou cannot be ignored.Both Abs365 and MAE365 had the same seasonal variation trend as WSOC,which was related to the composition and emission sources of WSOC in different seasons.关键词
水溶性有机碳/污染特征/季节变化/来源/吸光特性Key words
WSOC/pollution characteristics/seasonal variation/source/light absorption properties分类
资源环境引用本文复制引用
张俊美,王志宇,杨本勇,杨书申,杨凌霄..PM2.5中水溶性有机碳的污染特征、吸光特性和来源研究[J].生态环境学报,2024,33(7):1072-1078,7.基金项目
国家自然科学基金项目(41375145) （41375145）
河南省自然科学基金项目(212300410322) （212300410322）
青年人才创新能力基金项目(K2020QN017) （K2020QN017）
