喀斯特小流域石灰土硫同位素组成特征及环境指示意义

发布时间：2018-04-13 03:03

本文选题：喀斯特小流域 + 石灰土　；参考：《地球化学》2016年06期

【摘要】：用连续提取方法分析了石灰土总硫、SO_4~(2 )、总还原态硫(TRS)和有机硫的硫同位素组成,探讨了石灰土中硫的迁移转化过程及其环境效应。有机硫是石灰土主要的硫形态,随剖面加深总硫和有机硫的δ34S值逐渐增大,其含量降低,这与有机硫持续矿化有关。SO_4~(2 )和TRS的δ34S值随剖面加深平行地增大指示了石灰土中存在SO_4~(2 )异化还原过程,并且TRS是主要产物。高pH值和较低的黏粒含量不利于SO_4~(2 )吸附,生物滞留后剩余的SO_4~(2 )主要通过淋溶迁移出石灰土剖面。当前酸沉降对石灰土的影响并不严重,SO_4~(2 )的淋溶迁移并没有引起石灰土pH值的显著降低。但值得关注的是,有机硫形态是酸沉降输入的SO_4~(2 )在石灰土中主要的硫滞留方式,SO_4~(2 )吸附基本可以忽略,则在硫的年沉降速率显著降低之后,在较长时期内,石灰土中有机硫的矿化可能释放大量的SO_4~(2 )进入地表和地下水体,与之相关的土壤理化性质变化和水体化学组成改变等方面的环境效应值得关注。
[Abstract]:The sulfur isotopic compositions of total sulfur, total reduced sulfur (TRS) and organic sulfur in lime soil were analyzed by means of continuous extraction. The process of sulfur migration and transformation in lime soil and its environmental effects were discussed.Organic sulfur is the main sulfur form in lime soil. The 未 34 S value of total sulfur and organic sulfur increases gradually, and the content of organic sulfur decreases with the deepening of the profile.The 未 34S values of TRS and so _ 4) increase in parallel with the depth of the profile, indicating the existence of SO_4~(2 ~ (+) in lime soil, and TRS is the main product.High pH value and low clay content are not conducive to the adsorption of SO_4~(2. The residual SO_4~(2 ~ (2 +) is mainly transported out of the lime soil profile by leaching.At present, the effect of acid deposition on lime soil is not serious.However, it is worth paying attention to the fact that the main sulfur retention mode in lime soil is the form of organic sulfur (SO_4~(2), which is the input of acid deposition, which can be neglected, but after the annual rate of sulfur deposition is significantly reduced, the absorption rate of organic sulfur can be neglected for a long time.The mineralization of organic sulfur in lime soil may release a large amount of SO_4~(2 ~ +) into surface and underground water bodies. The environmental effects related to the changes of soil physical and chemical properties and chemical composition of water bodies are worthy of attention.
【作者单位】：贵州师范学院地理与旅游学院;中国科学院地球化学研究所环境地球化学国家重点实验室;中国科学院大学;
【基金】：国家自然科学基金(41463004;41103048) 贵州省自然科学基金(黔科合J字[2014]2135) 中国博士后基金(2015M572502)
【分类号】：P597;X142

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