Seasonal microbial variation accounts for arsenic dynamics in shallow alluvial aquifer systems

JOURNAL OF HAZARDOUS MATERIALS

卷:367

Article

Zheng, Tianliang¹  Deng, Yamin^1,2  Wang, Yanxin^2,3  Jiang, Hongchen³  O'Loughlin, Edward J.⁴  Flynn, Theodore M.^4,5  Gan, Yiqun^2,3  Ma, Teng^2,3 

[1] China Univ Geosci, Geol Survey, Wuhan 430074, Peoples R China

[2] China Univ Geosci, Sch Environm Studies, Wuhan 430074, Peoples R China

[3] China Univ Geosci, State Key Lab Biogeol & Environm Geol, Wuhan 430074, Peoples R China

[4] Argonne Natl Lab, Biosci Div, 9700 S Cass Ave, Argonne, IL 60439 USA

[5] Calif Dept Water Resources, 3500 Ind Blvd, West Sacramento, CA 96691 USA

关键词: Seasonal variation;    Groundwater level fluctuation;    Iron redox cycling;    Yangtze River Basin;    Microbial community dynamics;   

DOI  :  10.1016/j.jhazmat.2018.12.087

来源: Elsevier

【 摘 要 】

Determining the temporal variation of microbial communities in groundwater systems is essential to improve our understanding of hydrochemical dynamics in aquifers, particularly as it relates to the fate of redox-sensitive contaminants like arsenic (As). Therefore, a high-resolution hydrobiogeochemical investigation was conducted in the As-affected alluvial aquifer systems of the Jianghan Plain. In two 25 m-deep monitoring wells, the seasonal variation in the composition of groundwater microbial communities was positively correlated with the change in groundwater level (R = 0.47 and 0.39 in NH03B and NH05B, respectively, P < 0.01), implying that the latter could be a primary driver of the seasonal microbial dynamics. In response to the fluctuating groundwater level, iron (Fe) reducers within the Desulfuromonadales were dominant (9.9 +/- 4.7% among different sampling sites) in groundwater microbial communities during the monsoon season and associated with high concentrations of Fe (II) and As, while the predominance (16.7 +/- 15.2% among different sampling sites) of iron-oxidizers the Gallionellaceae was accompanied by low Fe(II) and As in the non-monsoon season. These results suggest that microbially-mediated iron reduction/oxidation may have governed the seasonal mobilization/scavenging of As in groundwater. Our results provide new insights into mechanisms responsible for seasonal variations in groundwater As concentrations in similar aquifer systems.

【 授权许可】

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