广州地区不同粒径段大气颗粒物中水溶性有机碳的吸光贡献  

The size-resolved light absorption contribution of water soluble organic carbon in the atmosphere of Guangzhou

作　　者：郭子雍 阳宇翔 彭龙 廉秀峰 傅玉珍 张国华[1,3] 毕新慧[1,3] 王新明[1,3] GUO Zi-yong;YANG Yu-xiang;PENG Long;LIAN Xiu-feng;FU Yu-zhen;ZHANG Guo-hua;BI Xin-hui;WANG Xin-ming(Guangdong Key Laboratory of Environmental Protection and Resources Utilization,State Key Laboratory of Organic Geochemistry,Guangzhou Institute of Geochemistry,Chinese Academy of Sciences,Guangzhou 510640,China;University of Chinese Academy of Sciences,Beijing 100049,China;Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control,Guangzhou Institute of Geochemistry,Chinese Academy of Sciences,Guangzhou 510640,China)

机构地区：[1]中国科学院广州地球化学研究所,有机地球化学国家重点实验室,广东省环境资源利用与保护重点实验室,广东广州510640 [2]中国科学院大学,北京100049 [3]中国科学院广州地球化学研究所,粤港澳环境污染过程与控制联合实验室,广东广州510640

出　　处：《中国环境科学》2021年第2期497-504,共8页China Environmental Science

基　　金：国家自然科学基金资助项目(41775124,41877307);广东省科技计划项目(2019B121205006,2017B030314057)。

摘　　要：对广州地区春季(2015年3~4月)、夏季(2015年6~7月)、秋季(2015年9~10月)、冬季(2015年12月~2016年1月)四个季节6个粒径段(<0.49、0.49~0.95、0.95~1.5、1.5~3.0、3.0~7.2以及7.2~10.0μm)的大气颗粒物样品中水溶性有机碳(WSOC)的浓度和光学性质等变化特征进行了研究.结果表明,WSOC的浓度水平呈现冬季[(5.07±2.80)μg/m^(3)]>秋季[(3.87±1.51)μg/m^(3)]>春季[(3.60±1.16)μg/m^(3)]>夏季[(2.42±0.51)μg/m^(3)]的季节变化特征;WSOC的质量平均直径(MMD)为0.57μm(春)、0.42μm(夏)、0.49μm(秋)和0.56μm(冬).WSOC的质量吸收效率MAE365差异较大,分布在0.18~1.42m^(2)/g之间,冬季最高;吸收波长指数AAE值分布在3.6~9.8之间.细颗粒物(<3μm)中WSOC对PM10WSOC总吸光的贡献达到了90%以上,其中<0.49μm颗粒物的贡献超过50%.在300~500nm之间,春季、夏季、秋季和冬季WSOC对颗粒物总吸光比例平均值分别为5.23%、2.95%、3.04%和6.92%;其中<0.49μm粒径段的贡献最高,分别为3.11%、1.79%、1.65%和3.45%.进一步通过特征紫外吸光度SUVA值的分析表明芳香性和分子量可能是影响WSOC吸光能力的重要因素.粒径越小颗粒物含有越多的不饱和键,使得MAE365值较高.The concentrations and optical properties of water-soluble organic carbon(WSOC)in the size-resolved aerosols of Guangzhou collected during spring(Mar.to Apr.2015),summer(Jun.to Jul.2015),autumn(Sept.to Oct.2015),and winter(Dec.2015 to Jan.2016)were investigated.The results showed that the concentration levels of WSOC were in the order of winter[(5.07±2.80)μg/m^(3)]>autumn[(3.87±1.51)μg/m^(3)]>spring[(3.60±1.16)μg/m^(3)]>summer[(2.42±0.51)μg/m^(3)],and the mass mean diameter of WSOC in each season was 0.57μm(spring),0.42μm(summer),0.49μm(autumn),and 0.56μm(winter),respectively.The MAE365 of WSOC varied in a wide range of 0.18~1.42m^(2)/g,with the highest value observed in winter,and the AbsorptionÅngstr m Exponent(AAE)varied in a wide range of 3.6~9.8.The light absorption of WSOC in fine particles(<3μm)contributed more than 90%to the total absorption of PM10,and more than 50%was attributed to WSOC in the<0.49μm particles.Over the wavelength of 300~500nm,the average proportion of WSOC light absorption to total aerosol absorption in spring,summer,autumn,and winter was 5.23%,2.95%,3.04%,and 6.92%,respectively,and the<0.49μm particles represented the highest contribution,which was 3.11%,1.79%,1.65%,and 3.45%,respectively.Further analysis of the specific UV Absorbance(SUVA)indicated that the aromatic content and molecular weight of WSOC might be important components affecting their light-absorbing efficiencies.The higher MAE365 values observed in the finer particles are associated with more unsaturated bonds.

关 键 词：气溶胶 水溶性有机碳(WSOC) 光学性质 粒径分布 

分 类 号：X513[环境科学与工程—环境工程]