Sulfur isotopic composition and source identification of atmospheric environment in central Zhejiang,China  

作　　者：Zhang MiaoYun Wang ShiJie Ma GuoQiang Zhou HuaiZhong Fu Jun 

机构地区：[1]Chinese Acad Sci, Inst Geochem, State Key Lab Environm Geochem, Guiyang 550002, Peoples R China [2]Jinhua Environm Monitoring Ctr, Jinhua 321013, Peoples R China [3]Environm Monitoring Ctr Zhejiang Prov, Hangzhou 310012, Zhejiang, Peoples R China

出　　处：《Science China Earth Sciences》2010年第11期1717-1725,共9页中国科学（地球科学英文版）

基　　金：supported by National Basic Research Program of China (Grant No.2006CB403200);National Natural Science Foundation of China (Grant No.40721002);Science Plan Program of Zhejiang Province (Grant No.2004C33072);Environmental Protection Research Program of Zhejiang Province (Grant No.200720);Science and Technology Research Program of Jinhua City (Grant No.2008-3-001)

摘　　要：Sulfur dioxide and sulfate aerosols in the atmosphere are significant factors leading to acidification of the atmospheric environment and worsening the pollution of acid deposition. Because of the "fingerprint" characteristics of the stable sulfur isotopic composition, sulfur isotope has been widely adopted in environmental researches concerning sulfur cycle and source identification. In this study, the atmospheric environment of Jinhua City, central Zhejiang Province, was continuously monitored, and the sulfur isotopic composition of SO2 and sulfate aerosols in the atmosphere was analyzed. The results indicate that the variation of δ34S values for SO2 ranges from 1.0‰ to 7.5‰, and annual average is 4.7‰±2.3‰, whereas that of sulfate aerosols ranges from 6.4‰ to 9.8‰,and annual average is 8.1‰±1.0‰. The δ 34S values for SO2 have significant seasonal variations, which are 7.0‰ in winter and 3.3‰ in summer. These variations cannot be attributed to a single factor, and we suggest a temperature-dependent isotope equilibrium fractionation and elevated biogenic sulfur emissions of isotopically light S in summer may be the main controlling mechanisms. Furthermore, we also discuss the δ 34S model of atmospheric SO2 oxidation to form sulfate, and suggest that heterogeneous oxidation dominates in the oxidation reactions of atmospheric SO2 in the central Zhejiang Province. We further suggest that the relative humidity in the atmosphere plays an important role in the oxidation mechanism of atmospheric SO2.Sulfur dioxide and sulfate aerosols in the atmosphere are significant factors leading to acidification of the atmospheric environment and worsening the pollution of acid deposition. Because of the 'fingerprint' characteristics of the stable sulfur isotopic composition, sulfur isotope has been widely adopted in environmental researches concerning sulfur cycle and source identification. In this study, the atmospheric environment of Jinhua City, central Zhejiang Province, was continuously monitored, and the sulfur isotopic composition of SO2 and sulfate aerosols in the atmosphere was analyzed. The results indicate that the variation of δ34S values for SO2 ranges from 1.0‰ to 7.5‰, and annual average is 4.7‰±2.3‰, whereas that of sulfate aerosols ranges from 6.4‰ to 9.8‰,and annual average is 8.1‰±1.0‰. The δ 34S values for SO2 have significant seasonal variations, which are 7.0‰ in winter and 3.3‰ in summer. These variations cannot be attributed to a single factor, and we suggest a temperature-dependent isotope equilibrium fractionation and elevated biogenic sulfur emissions of isotopically light S in summer may be the main controlling mechanisms. Furthermore, we also discuss the δ 34S model of atmospheric SO2 oxidation to form sulfate, and suggest that heterogeneous oxidation dominates in the oxidation reactions of atmospheric SO2 in the central Zhejiang Province. We further suggest that the relative humidity in the atmosphere plays an important role in the oxidation mechanism of atmospheric SO2.

关 键 词：SULFUR ISOTOPE SO2 AEROSOL HOMOGENEOUS OXIDATION heterogeneous OXIDATION 

分 类 号：N[自然科学总论]