硼同位素分馏及其在地下水研究中的应用进展  

Boron isotopes fractionation and its application progress in groundwater research

作　　者：雷郴博 郭华明[1] 邢世平 LEI Chenbo;GUO Huaming;XING Shiping(School of Water Resource and Environment,China University of Geosciences(Beijing),Beijing 100083,China)

机构地区：[1]中国地质大学(北京)水资源与环境学院,北京100083

出　　处：《水文地质工程地质》2024年第6期219-231,共13页Hydrogeology & Engineering Geology

摘　　要：硼(B)在自然界水体和岩石中广泛存在,B的2种稳定同位素(10B和11B)相对质量差较大,因此B同位素容易产生明显的分馏。在不同水文地质环境下,地下水往往具有不同的B同位素组成(δ^(11)B),研究地下水B同位素组成及变化,对认识水文地球化学过程以及合理开发地下水资源具有重要的指导意义。文章在介绍B同位素分馏原理的基础上,归纳了吸附/共沉淀作用、解吸附作用、风化作用、蒸发作用等水文地球化学过程对地下水δ^(11)B值的影响。较为系统地梳理了B同位素技术在地下水研究中的应用成果:(1)由于污染源和海水的δ^(11)B值往往与地下水背景值存在明显差异,因此可利用B同位素示踪地下水污染与海水入侵;(2)不同矿物δ^(11)B值的差异和风化条件的差异会显著影响地下水δ^(11)B值,通过B同位素能反映矿物的风化特征、识别地热水与围岩相互作用过程;(3)地下水B同位素还能用于示踪与氟、砷富集相关的水文地球化学过程,从而完善高氟、高砷地下水的形成机理。在此基础上,分析了B同位素技术在地下水研究中的应用潜力:(1)将B同位素技术与水化学方法及其他同位素技术相结合,量化不同水文地球化学过程对目标组分迁移转化的贡献;(2)对富B地热水、天然劣质地下水地区进行B同位素长期监测,确定不同环境条件下的地下水B端元,定量评估有害组分对环境造成的负面影响。这些科学问题的解决不仅能推动B同位素技术在地下水研究中的进一步发展,还有助于提高对地下水有害组分形成机制的整体认识。Boron(B)is ubiquitous in natural water bodies and rocks.Because of the large relative mass difference between the two stable isotopes of B,10B and 11B,the B isotopes are susceptible to significant fractionation.Groundwater typically exhibits variousδ^(11)B in different hydrogeological environments.The composition and variation of B isotope in groundwater are of great significance to understanding hydrogeochemical processes and the rational development of groundwater resources.Based on the introduction of the principle of B isotope fractionation,this review summarizes the effects of hydrogeochemical processes such as adsorption/coprecipitation,desorption,weathering,and evaporation on groundwaterδ^(11)B values.The article systematically present the studies on applying B isotope technique to address hot academic issues.Since theδ^(11)B values of contaminants and seawater often differ significantly from groundwater background values,B isotopes can be utilized to trace both groundwater contamination and seawater intrusion.Differences in theδ^(11)B values of distinct minerals and weathering conditions have a significant impact on theδ^(11)B values of groundwater.Therefore,B isotopes are useful in reflecting the weathering characteristics of minerals and identifying the process of interaction between the geothermal water and the surrounding rocks.B isotopes can also be utilized to trace hydrogeochemical processes associated with the enrichment of fluoride and arsenic,thereby enhancing the knowledge of the formation mechanism of high fluoride and arsenic groundwater.The future studies on groundwater B isotopes should focus on:(1)Supplementing B-isotope techniques with water chemistry and other isotope techniques to quantify contributions of different hydrogeochemical processes to of the specific solute transformation.(2)Long-term monitoring of B isotopes in areas with high B geothermal water and natural inferior groundwater to determine B endmembers in different conditions and to quantitively assess the negative imp

关 键 词：硼同位素 地下水污染 风化 地热水 高氟地下水 高砷地下水 

分 类 号：P641[天文地球—地质矿产勘探]