石家庄地区地下水中溶解性有机碳同位素特征及其环境指示意义  

Characteristics of dissolved organic carbon isotope in groundwater in Shijiazhuang and its environmental implications

作　　者：张彦鹏[1,2,3] 周爱国[1,2] 周建伟[1,2] 刘存富[1,2] 蔡鹤生[1,2] 徐文[1,2,3] 刘运德[1,2,3] 方晶晶[1,2,3] 

机构地区：[1]中国地质大学(武汉)环境学院,湖北武汉430074 [2]生物地质与环境地质国家重点实验室,湖北武汉430074 [3]中国地质大学(武汉)研究生院,湖北武汉430074

出　　处：《水文地质工程地质》2013年第3期12-18,共7页Hydrogeology & Engineering Geology

基　　金：国家自然科学基金项目(41002083、40972157)

摘　　要：溶解性有机碳(DOC)是地下水中微生物代谢活动的主要能量来源,δ13CDOC值是指示DOC来源及生物代谢活动的重要参数。通过对石家庄地区浅层地下水中DOC浓度及δ13CDOC特征进行分析,结合相应的水化学检测,探讨了δ13CDOC值对地下水环境演化的指示作用。结果表明:DOC浓度及其同位素特征均受到天然及人为两方面影响,表现出一定的空间特征。在垂向上,除石家庄西北部地区以外,研究区地下水中DOC浓度随地下水埋深的增大有降低趋势,δ13CDOC随地下水埋深的增大而增大;石家庄西北部地区具有一定特殊性,地下水埋深较浅,交替强烈,TOC含量较高,而DOC浓度较低,δ13CDOC值偏负。在水平方向上,滹沱河沿岸地区,沿地下水流向,DOC浓度逐渐降低,δ13CDOC值逐渐偏正。石家庄南部地区受污灌影响,DOC浓度较高,δ13CDOC值偏负。研究区地下水埋藏深度、补给条件、径流特征以及人为作用均对地下水中DOC浓度及其同位素特征产生显著影响。δ13CDOC值与SO24-、NO3-浓度的相关关系指示出研究区地下水中反硝化作用和硫酸盐还原作用的发生,从吴家营、宋营一带开始逐渐由硝酸盐还原环境向硫酸盐还原环境过渡;沿地下水流向,地下水环境还原程度增强。Dissolved organic carbon(DOC) is the main energy source of microbial metabolism in groundwater,and 13CDOC is an important parameter to indicate the DOC sources and biological metabolism.This article examines the role of 13CDOC to indicate the changes in groundwater environment through the characteristics of 13CDOC combined with corresponding water chemistry test results.The results show that DOC concentration and 13CDOCare impacted by natural and human factors with certain spatial characteristics.In the vertical direction,DOC concentration decreases with increasing depth of groundwater,and 13CDOC increases with increasing depth of groundwater except the northwestern part of Shijiazhuang.The northwestern district of Shijiazhuang is special with strongly alternative shallow groundwater,in which TOC concentration is high,but DOC concentration is low and 13CDOC is more negative than downstream.In the horizontal direction,DOC concentration is more and more low,but 13CDOC is more and more positive along the flow direction of groundwater near the Hutuo river.The southern district of Shijiazhuang is impacted by sewage irrigation with higher DOC concentration and lower 13CDOC.The depth of groundwater,groundwater recharge,hydrogeological conditions and human activities all impact the DOC concentration and 13CDOC in groundwater.13CDOCvs.NO-3 and 13CDOCvs SO2-4 indicate the occurrence of denitrification and sulfate reduction processes,and also show that the reductive groundwater environment gradually enhances from denitrification to sulfate reduction along the flow direction at the district near Wujiaying and Songying.

关 键 词：石家庄地区 溶解性有机碳 地下水 碳同位素 生物地球化学作用 

分 类 号：P641.12[天文地球—地质矿产勘探]