编号：CDUT-2023-59

标题：Hydrogeochemical controls on As and B enrichment in the aqueous environment from the Western Tibetan Plateau: A case study from the Singe Tsangpo River Basin

入藏号：WOS:000743200100002

中国科学院文献情报中心期刊分区：环境科学与生态学1区/TOP（2022）

本校作者：郑天亮；邓杨；林河；谢燕华；裴向军

来源出版物：SCIENCE OF THE TOTAL ENVIRONMENT  卷: 817  文献号: 152978

出版年：2022 

第一地址：成都理工大学

关键词： Arsenic；Boron；Singe Tsangpo River；Groundwater；Water chemistry；Chemical weathering

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摘要：Although enrichment of As and B has been extensively observed in major rivers within the Tibetan Plateau, the mechanisms regulating natural enrichment of As and B in the river basins remain poorly understood. To evaluate the hydrogeochemical controls on the As and B enrichment in the aqueous environment in the western Tibetan Plateau, samples of river waters, river sediments, and groundwater were collected within the Singe Tsangpo River basin. The results revealed significant enrichment of As and B in river water (up to 104 μg/L for As and 3.2 mg/L for B), river sediment (up to 141 mg/kg for As and 79.4 mg/kg for B), and groundwater (up to 73 μg /L for As and 2.5 mg/L for B). Moreover, the decreases in the molar ratios from the Ca2+/(Na++K+) in river water and the chemical index of alteration (CIA) in the sediments accompanied with the enrichment of heavier δ18O values along the river flow path suggested that, carbonate and silicate weathering were more substantial at the upper reaches, and the dissolution of evaporites was enhanced at the lower reaches. The As and B enrichment in the river waters primarily resulted from the discharge of geothermal springs, while the carbonate weathering has facilitated the B enrichment through providing HCO3- for the competitive adsorption with H3BO3 or B(OH)4-. In addition, the recharge of surface water into groundwater resulted in elevated As and B concentrations in the alluvial aquifers at the lower reaches of the Singe Tsangpo River. The present study highlighted that variations in the weathering processes within the river basin could significantly contribute to the enrichment of As and B, which can improve our understanding of hydrogeochemical controls on the transport and enrichment of trace elements at the catchment scale worldwide.

文章链接地址: http://dx.doi.org/10.1016/j.scitotenv.2022.152978