Carbon and methane cycling in arsenic-contaminated aquifers

WATER RESEARCH

卷:200

Article

Stopelli, Emiliano^1,11  Duyen, Vu T.²  Prommer, Henning^3,4  Glodowska, Martyna⁵  Kappler, Andreas⁵  Schneider, Magnus⁶  Eiche, Elisabeth⁶  Lightfoot, Alexandra K.¹  Schubert, Carsten J.^8,9  Trang, Pham K. T.²  Viet, Pham H.²  Kipfer, Rolf^1,9  Winkel, Lenny H. E.^1,9  Berg, Michael^1,10 

[1] Eawag, Swiss Fed Inst Aquat Sci & Technol, Dept Water Resources & Drinking Water, CH-8600 Dubendorf, Switzerland

[2] Vietnam Natl Univ, VNU Univ Sci, Key Lab Analyt Technol Environm Qual & Food Safet, Hanoi, Vietnam

[3] CSIRO Land & Water, Floreat, WA 6014, Australia

[4] Univ Western Australia, Sch Earth Sci, Crawley, WA 6009, Australia

[5] Univ Tubingen, Ctr Appl Geosci, Geomicrobiol, D-72076 Tubingen, Germany

[6] Karlsruhe Inst Technol, Inst Appl Geosci, D-76131 Karlsruhe, Germany

[7] AdvectAs, Stockholm, Sweden

[8] Eawag, Swiss Fed Inst Aquat Sci & Technol, Dept Surface Waters Res & Management, CH-6047 Kastanienbaum, Switzerland

[9] Swiss Fed Inst Technol, Inst Biogeochem & Pollutant Dynam, CH-8092 Zurich, Switzerland

[10] Univ Southern Queensland, Sch Civil Engn & Surveying, UNESCO Chair Groundwater Arsen 2030 Agenda Sustai, Toowoomba, Qld 4350, Australia

[11] Nagra, Natl Cooperat Disposal Radioact Waste Int Serv &, CH-5430 Wettingen, Switzerland

关键词: Groundwater quality;    Drinking water;    Geogenic As contamination;    Heterogeneity;    Organic matter;    Carbon isotope delta C-13;   

DOI  :  10.1016/j.watres.2021.117300

来源: Elsevier

【 摘 要 】

Geogenic arsenic (As) contamination of groundwater is a health threat to millions of people worldwide, particularly in alluvial regions of South and Southeast Asia. Mitigation measures are often hindered by high heterogeneities in As concentrations, the cause(s) of which are elusive. Here we used a comprehensive suite of stable isotope analyses and hydrogeochemical parameters to shed light on the mechanisms in a typical high-As Holocene aquifer near Hanoi where groundwater is advected to a low-As Pleistocene aquifer. Carbon isotope signatures (delta C-13-CH4, delta C-13-DOC, delta C-13-DIC) provided evidence that fermentation, methanogenesis and methanotrophy are actively contributing to the As heterogeneity. Methanogenesis occurred concurrently where As levels are high (>200 mu g/L) and DOC-enriched aquitard pore water infiltrates into the aquifer. Along the flowpath to the Holocene/Pleistocene aquifer transition, methane oxidation causes a strong shift in delta C-13-CH4 from -87 parts per thousand to +47 parts per thousand, indicating high reactivity. These findings demonstrate a previously overlooked role of methane cycling and DOC infiltration in high-As aquifers. (C) 2021 The Author(s). Published by Elsevier Ltd.

【 授权许可】

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