Arsenic behavior in groundwater in Hanoi (Vietnam) influenced by a complex biogeochemical network of iron, methane, and sulfur cycling

JOURNAL OF HAZARDOUS MATERIALS

卷:407

Article

Glodowska, Martyna^1,2  Stopelli, Emiliano³  Straub, Daniel^2,4  Thi, Duyen Vu⁵  Trang, Pham T. K.⁵  Viet, Pham H.⁵  Berg, Michael^3,6  Kappler, Andreas¹  Kleindienst, Sara^2,3 

[1] Univ Tubingen, Ctr Appl Geosci, Geomicrobiol, Tubingen, Germany

[2] Univ Tubingen, Ctr Appl Geosci, Microbial Ecol, Tubingen, Germany

[3] Swiss Fed Inst Aquat Sci & Technol, Eawag, Dubendorf, Switzerland

[4] Univ Tubingen, Quantitat Biol Ctr QBiC, Tubingen, Germany

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

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

关键词: Arsenic cycling;    Microbial processes;    Groundwater hydrochemistry;    Fermentation;    Methanotrophy;    Methanogenesis;    Sulfate reduction;   

DOI  :  10.1016/j.jhazmat.2020.124398

来源: Elsevier

【 摘 要 】

The fate of arsenic (As) in groundwater is determined by multiple interrelated microbial and abiotic processes that contribute to As (im)mobilization. Most studies to date have investigated individual processes related to As (im)mobilization rather than the complex networks present in situ. In this study, we used RNA-based microbial community analysis in combination with groundwater hydrogeochemical measurements to elucidate the behavior of As along a 2 km transect near Hanoi, Vietnam. The transect stretches from the riverbank across a strongly reducing and As-contaminated Holocene aquifer, followed by a redox transition zone (RTZ) and a Pleistocene aquifer, at which As concentrations are low. Our analyses revealed fermentation and methanogenesis as important processes providing electron donors, fueling the microbially mediated reductive dissolution of As-bearing Fe(III) minerals and ultimately promoting As mobilization. As a consequence of high CH4 concentrations, methanotrophs thrive across the Holocene aquifer and the redox transition zone. Finally, our results underline the role of SO42- reducing and putative Fe(II)-/As(III)-oxidizing bacteria as a sink for As, particularly at the RTZ. Overall, our results suggest that a complex network of microbial and biogeochemical processes has to be considered to better understand the biogeochemical behavior of As in groundwater.

【 授权许可】

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