Codeposition of Organic Carbon and Arsenic in Bengal Delta Aquifers
| العنوان: | Codeposition of Organic Carbon and Arsenic in Bengal Delta Aquifers |
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| المؤلفون: | Andrew A. Meharg, David G Kinniburgh, Paul N. Williams, Kenneth Cruickshank, Kenneth Fuller, Charles M. Scrimgeour, Shahid Akhtar Hossain |
| المصدر: | Environmental Science & Technology. 40:4928-4935 |
| بيانات النشر: | American Chemical Society (ACS), 2006. |
| سنة النشر: | 2006 |
| مصطلحات موضوعية: | Delta, Geologic Sediments, chemistry.chemical_element, Arsenic, Sedimentary depositional environment, chemistry.chemical_compound, Water Supply, Water Movements, Soil Pollutants, Environmental Chemistry, Water Pollutants, Total organic carbon, Hydrology, Bangladesh, Detritus, Water Pollution, fungi, Arsenate, Sediment, General Chemistry, Carbon, chemistry, Environmental chemistry, Sedimentary rock, Water Pollutants, Chemical, Geology, Environmental Monitoring |
| الوصف: | We present data showing that arsenic (As) was codeposited with organic carbon (OC) in Bengal Delta sediments as As and OC concentrations are highly (p < 0.001) positively correlated in core profiles collected from widely dispersed geographical sites with different sedimentary depositional histories. Analysis of modern day depositional environments revealed that the As−OC correlations observed in cores are due to As retention and high OC inputs in vegetated zones of the deltaic environment. We hypothesize that elevated concentrations of As occur in vegetated wetland sediments due to concentration and retention of arsenate in aerated root zones and animal burrows where copious iron(III) oxides are deposited. On burial of the sediment, degradation of organic carbon from plant and animal biomass detritus provides the reducing conditions to dissolve iron(III) oxides and release arsenite into the porewater. As tubewell abstracted aquifer water is an invaluable resource on which much of Southeast Asia is now dependent, this increased understanding of the processes responsible for As buildup and release will identify, through knowledge of the palaeosedimentary environment, which sediments are at most risk of having high arsenic concentrations in porewater. Our data allow the development of a new unifying hypothesis of how As is mobilized into groundwaters in river flood plains and deltas of Southeast Asia, namely that in these highly biologically productive environments, As and OC are codeposited, and the codeposited OC drives As release from the sediments. |
| تدمد: | 1520-5851 0013-936X |
| DOI: | 10.1021/es060722b |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::856bd4913d7d92f1eb0f6f170ad990e4 https://doi.org/10.1021/es060722b |
| رقم الانضمام: | edsair.doi.dedup.....856bd4913d7d92f1eb0f6f170ad990e4 |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 15205851 0013936X |
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| DOI: | 10.1021/es060722b |