简介: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” characte简介: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.详细>