太行山前倾斜平原地下水硫酸盐来源解析

Source Analysis of Groundwater Sulfate in Inclined Plain in Front of Taihang Mountain

济源地下水中硫酸盐(SO_(4)^(2-))含量持续升高,其来源尚不明晰,解析硫酸盐的来源对地下水开发利用尤为关键。文章于2018年3月进行了水样采集与相关指标的测试,并采用氢氧同位素、离子比例分析和贝叶斯稳定同位素混合模型,分析地下水SO_(4)^(2-)、硫酸盐中δ^(34)S的分布特征,解析硫酸盐来源,确定来源贡献比例。结果表明:地下水化学类型以Ca·Mg-HCO_(3)·SO_(4)为主,主要接受大气降水及地表水的补给;受大气降水及地表水的稀释、硫酸盐还原作用影响,沿径流路径SO_(4)^(2-)含量减小,δ^(34)S增大。研究区东、南部地表水和地下水的各硫酸盐来源比例大体相同;西部水体的硫酸盐主要受污水的影响,其中地表水受大气降水的影响也较大;北部地表水硫酸盐含量主要受大气降水、污水的影响,孔隙水主要受煤系地层硫化物氧化、污水的影响,岩溶水主要受大气降水、硫化物氧化的影响。研究结果可为地下水资源的有效管理和保护提供重要依据。

The content of sulfate(SO_(4)^(2-))in groundwater of Jiyuan City has been rising continuously according to a number of researches,and its source has been yet unclear.It is especially critical to analyze the source of sulfate(SO_(4)^(2-))for groundwater exploitation and utilization.Accordingly,to this end,the groundwater sampling project was carried out involving samples collection and the tests of related chemical indicators in March 2018.By using the hydrogen and oxygen isotope ion ratio analysis and Bayesian stable isotope mixing model the distribution characteristics of SO_(4)^(2-)andδ^(34)S were analyzed,and the sources of sulfate were traced and analyzed,and their contribution proportions determined.As a result,it showed the chemical type of groundwater was mainly Ca·Mg-HCO_(3)·SO_(4)and groundwater was mainly recharged by atmospheric precipitation and surface water;affected by the dilution of precipitation and surface water,as well as the reduction action of sulfates,the content of SO_(4)^(2-)decreased andδ^(34)S increased along the runoff path;the proportions of sulfate sources of surface water and groundwater were roughly similar in the west and south parts of the study area.In the west part,sulfates in the water bodies were mainly influenced by sewage discharged,and the surface water was also comparatively affected by atmospheric precipitation,while in the north part,sulfate content in surface water was mainly influenced by atmospheric precipitation and sewage.Additionally,as for the pore water,sulfide oxidation in the coal measure strata and sewage discharged were the major influencing factors.In conclusion,the research results could provide considerable basis for effective management and protection of groundwater resources.