喀斯特小流域黄壤硫同位素组成特征——对环境过程和效应的指示

发布时间：2018-06-22 12:16

本文选题：喀斯特小流域 + 黄壤　；参考：《中国环境科学》2016年09期

【摘要】：用连续提取方法分析了黄壤中总硫、SO_4~(2-)、总还原态硫(TRS)和有机硫的硫同位素组成,探讨黄壤中硫的迁移转化过程及其环境效应.有机硫是主要的硫形态,SO_4~(2-)是主要的无机硫形态.TRS具有最低的δ~(34)S值,同时SO_4~(2-)和TRS的δ~(34)S值随剖面加深而平行地增大指示黄壤中存在SO_4~(2-)异化还原过程.黄壤剖面中总硫和有机硫的δ~(34)S值先增大后降低与有机硫矿化及有机硫组分的迁移和底层吸附有关.生物滞留后剩余SO_4~(2-)的吸附、解吸、淋溶迁移及深层吸附与累积导致剖面中SO_4~(2-)的δ~(34)S值先增大后明显降低.酸沉降下剖面中SO_4~(2-)的吸附、解吸和淋溶迁移可引起黄壤酸化.值得关注的是,酸沉降输入的SO_4~(2-)主要以有机硫和吸附态SO_4~(2-)滞留在黄壤中,则在硫的年沉降速率大幅降低后,在较长时期内,黄壤中有机硫矿化和吸附态SO_4~(2-)解吸可能释放大量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 so _ 4 ~ (2-), total reduced sulfur (TRS) and organic sulfur in yellow soil were analyzed by means of continuous extraction, and the process of sulfur migration and transformation in yellow soil and its environmental effects were discussed. Organic sulfur is the main sulfur form so _ 4 ~ (2-) is the main inorganic sulfur form. TRS has the lowest 未 ~ (34) S value. Meanwhile, the 未 ~ (34) S value of so _ 4 ~ (2-) and TRS increases in parallel with the deepening of the profile, indicating that there is a dissimilatory reduction process of so _ (4) ~ (2-) in yellow soil. The 未 ~ (34) S value of total and organic sulfur in the profile of yellow soil increased first and then decreased, which was related to the mineralization of organic sulfur, the migration of organic sulfur components and the bottom layer adsorption. The adsorption, desorption, leaching migration and deep adsorption and accumulation of residual SO42- in the profile caused the 未 ~ (34) S value of SO42- in the profile to increase first and then to decrease obviously. The adsorption, desorption and leaching migration of SO42- in the profile of acid deposition can cause acidification of yellow soil. It is worth noting that the SO42- input from acid deposition is mainly trapped in yellow soil as organic sulfur and adsorbed SO42-, and then after the annual rate of sulfur deposition has been greatly reduced, the annual deposition rate of sulfur has been reduced for a longer period. The mineralization of organic sulfur and desorption of adsorbed SO42- in yellow soil may release a large amount of SO42- 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】：国家自然科学基金项目(41463004,41573081) 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】：S151.9

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