DOI: 10.1016/j.watres.2017.11.018
Scopus记录号: 2-s2.0-85033569431
论文题名: Insights into arsenic retention dynamics of Pleistocene aquifer sediments by in situ sorption experiments
作者: Neidhardt H. ; Winkel L.H.E. ; Kaegi R. ; Stengel C. ; Trang P.T.K. ; Lan V.M. ; Viet P.H. ; Berg M.
刊名: Water Research
ISSN: 431354
出版年: 2018
卷: 129 起始页码: 123
结束页码: 132
语种: 英语
英文关键词: Arsenic behavior
; Arsenic remobilization
; Groundwater
; In situ sorption isotherm
; Iron oxyhydroxides
; Reducing conditions
Scopus关键词: Aquifers
; Arsenic
; Groundwater
; Groundwater pollution
; Hydrogeology
; Iron compounds
; Sediments
; Sorption
; Water management
; Groundwater abstraction
; Groundwater chemistry
; Groundwater monitoring wells
; Iron oxyhydroxides
; Pleistocene sediments
; Reducing conditions
; Remobilization
; Sorption isotherms
; Groundwater resources
; arsenic
; carbonic acid
; ground water
; mineral
; phosphorus
; silicon
; arsenic
; well water
; aquifer
; arsenic
; concentration (composition)
; delta
; enrichment
; flushing
; freshwater sediment
; groundwater
; groundwater abstraction
; Holocene
; hydrogeochemistry
; in situ measurement
; inorganic compound
; isotherm
; monitoring system
; Pleistocene
; redox conditions
; reduction
; remobilization
; retention
; sediment analysis
; sediment chemistry
; sorption
; well
; adsorption
; anoxia
; aquifer
; Article
; controlled study
; desorption
; environmental monitoring
; hydrodynamics
; laboratory
; oxidation reduction state
; Pleistocene
; priority journal
; sediment
; Viet Nam
; water contamination
; water management
; water retention
; adsorption
; chemistry
; oxidation reduction reaction
; sediment
; Asia
; Hanoi
; Viet Nam
; Adsorption
; Arsenic
; Environmental Monitoring
; Geologic Sediments
; Groundwater
; Oxidation-Reduction
; Water Wells
英文摘要: The migration of arsenic (As) enriched groundwater into Pleistocene aquifers as a consequence of extensive groundwater abstraction represents an increasing threat to the precious water resources in Asian delta regions. Pleistocene aquifer sediments are typically rich in FeIII-(hydr)oxides and are capable to adsorb high amounts of As. This results in a pronounced accumulation of As in Pleistocene aquifers, where high As groundwater infiltrates from adjacent Holocene aquifers. However, As retention by Pleistocene aquifers over long-term time scales remains largely unknown. We studied As sorption in situ by placing natural Pleistocene sediments and pure mineral phases directly inside groundwater monitoring wells at a study site near Hanoi (Vietnam). This in situ exposure allows for constant flushing of the samples with unaltered groundwater and the establishment of undisturbed sorption equilibria similar to those in local aquifer sediments, which is not readily attainable in traditional laboratory sorption experiments. The groundwaters in our experimental wells were characterized by different As concentrations (0.01–6.63 μmol/L) and redox states, reaching from suboxic to anoxic conditions (Eh of +159 to −4 mV). Results show that adsorption is the dominant As retention mechanism, independent from the respective groundwater chemistry (i.e. concentrations of dissolved P, HCO3 − and Si). Whilst most of the As sorbed within the first week, sorption further increased slowly but consistently by 6–189%, respectively, within six months. Hence, the As sorption behavior of Pleistocene aquifer sediments should be determined over longer periods to avoid an underestimation of the As sorption capacity. Accompanying desorption experiments revealed that about 51% of the sorbed As was remobilized within six months when exposed to low As groundwater. We therefore conclude that a considerable proportion of the As accumulated in the aquifer sediments is prone to remobilization once the As concentrations in migrating groundwater decline. Remobilization of As should be considered in local water management plans to avoid contamination of precious groundwater resources with this As legacy. © 2017 Elsevier Ltd Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/113073
Appears in Collections: 气候减缓与适应
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作者单位: Geoecology Eberhard Karls University Tübingen, Tübingen, 72070, Germany; Eawag, Swiss Federal Institute of Aquatic Science and Technology, Dübendorf, 8600, Switzerland; Institute of Biogeochemistry and Pollutant Dynamics, ETH Zurich, Universitätsstrasse 16, Zurich, CH-8092, Switzerland; Research Centre for Environmental Technology and Sustainable Development (CETASD), Hanoi University of Science, Vietnam National University, Hanoi, Viet Nam
Recommended Citation:
Neidhardt H.,Winkel L.H.E.,Kaegi R.,et al. Insights into arsenic retention dynamics of Pleistocene aquifer sediments by in situ sorption experiments[J]. Water Research,2018-01-01,129