干旱区生态环境知识资源中心(Arid): Hydrogeochemical and multi-tracer investigations of arsenic-affected aquifers in semi-arid West Africa

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DOI	10.1016/j.gsf.2018.06.004
	Hydrogeochemical and multi-tracer investigations of arsenic-affected aquifers in semi-arid West Africa
	Bretzler, Anja 1,2; Stolze, Lucien 3; Nikiema, Julien 4; Lalanne, Franck 5; Ghadiri, Elaheh 1,6; Brennwald, Matthias S.1; Rolle, Massimo 3; Schirmer, Mario 1,2
通讯作者	Bretzler, Anja
来源期刊	GEOSCIENCE FRONTIERS
ISSN	1674-9871
出版年	2019
卷号	10 期号:5 页码:1685-1699
英文摘要	The semi-arid Sahel regions of West Africa rely heavily on groundwater from shallow to moderately deep (<100 m b.g.l.) crystalline bedrock aquifers for drinking water production. Groundwater quality may be affected by high geogenic arsenic (As) concentrations (>10 mu g/L) stemming from the oxidation of sulphide minerals (pyrite, arsenopyrite) in mineralised zones. These aquifers are still little investigated, especially concerning groundwater residence times and the influence of the annual monsoon season on groundwater chemistry. To gain insights on the temporal aspects of As contamination, we have used isotope tracers (noble gases, H-3, stable water isotopes (H-2, O-18)) and performed hydrochemical analyses on groundwater abstracted from tube wells and dug wells in a small study area in southwestern Burkina Faso. Results revealed a great variability in groundwater properties (e.g. redox conditions, As concentrations, water level, residence time) over spatial scales of only a few hundred metres, characteristic of the highly heterogeneous fractured underground. Elevated As levels are found in oxic groundwater of circum-neutral pH and show little relation with any of the measured parameters. Arsenic concentrations are relatively stable over the course of the year, with little effect seen by the monsoon. Groundwater residence time does not seem to have an influence on As concentrations, as elevated As can be found both in groundwater with short (<50 a) and long (>10(3) a) residence times as indicated by He-3/He-4 ratios spanning three orders of magnitude. These results support the hypothesis that the proximity to mineralised zones is the most crucial factor controlling As concentrations in the observed redox/pH conditions. The existence of very old water portions with residence times >10(3) years already at depths of <50 m b.g.l. is a new finding for the shallow fractured bedrock aquifers of Burkina Faso, suggesting that overexploitation of these relatively low-yielding aquifers may be an issue in the future. (C) 2019, China University of Geosciences (Beijing) and Peking University. Production and hosting by Elsevier B.V.
英文关键词	Arsenic Groundwater chemistry West Africa Fractured aquifers Residence time Noble gases
类型	Article
语种	英语
国家	Switzerland ; Denmark ; Burkina Faso
开放获取类型	Green Submitted, Green Published, gold
收录类别	SCI-E
WOS记录号	WOS:000483372500005
WOS关键词	BURKINA-FASO ; NOBLE-GASES ; GROUNDWATER RECHARGE ; SPATIAL-DISTRIBUTION ; RADIOGENIC HELIUM ; DRINKING-WATER ; EXCESS AIR ; BASIN ; GOLD ; CONTAMINATION
WOS类目	Geosciences, Multidisciplinary
WOS研究方向	Geology
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/216039
作者单位	1.Eawag, Swiss Fed Inst Aquat Sci & Technol, Dubendorf, Switzerland; 2.Univ Neuchatel, Ctr Hydrogeol & Geothermie CHYN, Neuchatel, Switzerland; 3.Tech Univ Denmark DTU, Lyngby, Denmark; 4.Univ Ouaga I Pr Joseph KI ZERBO, Ouagadougou, Burkina Faso; 5.Inst Int Ingn Eau & Environm 2iE, Ouagadougou, Burkina Faso; 6.Swiss Fed Inst Technol, Dept Environm Syst Sci, Zurich, Switzerland
推荐引用方式 GB/T 7714	Bretzler, Anja,Stolze, Lucien,Nikiema, Julien,et al. Hydrogeochemical and multi-tracer investigations of arsenic-affected aquifers in semi-arid West Africa[J],2019,10(5):1685-1699.
APA	Bretzler, Anja.,Stolze, Lucien.,Nikiema, Julien.,Lalanne, Franck.,Ghadiri, Elaheh.,...&Schirmer, Mario.(2019).Hydrogeochemical and multi-tracer investigations of arsenic-affected aquifers in semi-arid West Africa.GEOSCIENCE FRONTIERS,10(5),1685-1699.
MLA	Bretzler, Anja,et al."Hydrogeochemical and multi-tracer investigations of arsenic-affected aquifers in semi-arid West Africa".GEOSCIENCE FRONTIERS 10.5(2019):1685-1699.