研究报告
张东,秦勇,赵志琦.我国北方小流域硫酸参与碳酸盐矿物化学风化过程研究[J].环境科学学报,2015,35(11):3568-3578
我国北方小流域硫酸参与碳酸盐矿物化学风化过程研究
- Chemical weathering of carbonate rocks by sulfuric acid on small basin in North China
- 基金项目：国家自然科学基金(No.41573095,41173030);河南理工大学博士基金项目(No.B2012-092)
- 作者
- 单位
- 张东
- 1. 河南理工大学资源环境学院, 焦作 454000;2. 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, 贵阳 550002
- 秦勇
- 河南理工大学资源环境学院, 焦作 454000
- 赵志琦
- 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, 贵阳 550002
- 摘要：硫酸参与碳酸盐岩的风化机制及与区域碳循环的关系是全球气候变化研究的重要课题.选择我国北方小流域(沁河)为研究对象,结合水化学及溶解性无机碳碳同位素组成,通过化学计算法,分析了河水溶解性组分的来源及混入比例,验证了硫酸参与区域碳酸盐的风化过程.结果表明:河水阳离子以Ca2+和Mg2+为主,阴离子以HCO3-和SO42-为主;沁河流域碳酸盐岩风化、大气输入及蒸发盐溶解对河水阳离子贡献较大,平均比例分别为48.5%、35.3%和14.1%,硅酸盐风化和人为输入贡献比例较小,平均比例分别为1.7%和0.6%;沁河流域碳酸盐类、硅酸盐类及蒸发盐类风化速率分别为8.41、0.07和2.43 t·km-2·a-1,碳酸盐和硅酸盐矿物风化CO2消耗量分别为1.43×105 mol·km-2·a-1和0.03×105 mol·km-2·a-1;沁河流域硫酸参与碳酸盐风化产生的CO2净释放量为0.63×105 mol·km-2·a-1,小于我国南方喀斯特地区CO2净释放量,可能与不同的气候条件及硫化物赋存条件和含量等有关.
- Abstract：The role of sulfuric acid in the chemical weathering of carbonate rock and its influences on the regional carbon cycling have been recognized as important issues for global climate change. One small drainage basin in North China named Qin River was selected in this study. The contributions from potential sources to the dissolved component were calculated based on chemical compositions of river water. Carbon isotopes of dissolved inorganic carbon were also used to verify the chemical weathering by sulfuric acid. The results demonstrated that Calcium and Magnesium were the dominant cations, and biocarbonate and sulfate were the dominant anions in the river water; Dissolved cations of river water were mainly controlled by carbonate weathering, atmospheric inputs, and evaporate dissolution with mean values of 48.5%, 35.3%, and 14.1%, respectively, while minor controlled by silicate weathering and human inputs which accounted for 1.7% and 0.6%, respectively; The chemical weathering rates of carbonate, silicate and evaporates in Qin River basin were estimated to be approximately 8.41, 0.07 and 2.43 t·km-2·a-1, respectively, and CO2 consumption rates for carbonate and silicate were 1.43×105 mol·km-2·a-1 and 0.03×105 mol·km-2·a-1, respectively; and CO2 released from carbonate chemical weathering by sulfuric acid was estimated to be 0.60×105 mol·km-2·a-1 lower than the results obtained in karst regions in South China. South China probably due to different climate and occurrence and content of sulfide.
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