Distribution and mobility of arsenic in the Río Dulce alluvial aquifers in Santiago del Estero Province, Argentina
Article
Article Title | Distribution and mobility of arsenic in the Río Dulce alluvial aquifers in Santiago del Estero Province, Argentina |
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ERA Journal ID | 3551 |
Article Category | Article |
Authors | Bhattacharya, Prosun, Claesson, Mattias, Bundschuh, Jochen, Sracek, Ondra, Fagerberg, Jens, Jacks, Gunnar, Martin, Raul A., Storniolo, Angel del R. and Thir, Juan M. |
Journal Title | Science of the Total Environment |
Journal Citation | 358 (1-3), pp. 97-120 |
Number of Pages | 24 |
Year | 01 Apr 2006 |
Publisher | Elsevier |
Place of Publication | Netherlands |
ISSN | 0048-9697 |
1879-1026 | |
Digital Object Identifier (DOI) | https://doi.org/10.1016/j.scitotenv.2005.04.048 |
Web Address (URL) | https://www.sciencedirect.com/science/article/abs/pii/S0048969705002561 |
Abstract | Factors controlling arsenic (As) mobilization in the aquifers of the Río Dulce alluvial cone were investigated. Groundwater analyses show severe As contamination (average concentration of 743 μg/L) from geogenic sources, but spatial variability of As concentration is considerable. Sequential leaching of sediment samples from unsaturated zone using de-ionised water, bicarbonate, acetate, and oxalate extracted As to different extents. Sediment oxalate extraction showed that Al and Mn oxide and hydroxides are more abundant than Fe oxides and hydroxides, in spite of similar total Fe, Mn, and Al concentrations in the sediment. Speciation calculations performed for saturated zone samples indicated that Fe and Al oxides and hydroxides are stable in groundwater, suggesting that As adsorption processes may be to some extent controlled by the presence of Fe and Al mineral phases. Principal Component Analysis (PCA) showed that As is related to F, V, Mo, B, Si, most likely due to their common origin in volcanic ash. This suggests the volcanic ash as the probable source of groundwater As. Locally, elevated pH values linked to carbonate dissolution, cation exchange, and dissolution of silicates promote release of adsorbed As. Another factor contributing to the release of As locally may be the input of organic matter from excessive irrigation. The conceptual model of As release includes: i) As influx from dissolution of volcanic glass in volcanic ash, ii) adsorption of As on the surface of Fe and Al mineral phases in relatively low pH zones, and iii) high mobility of As in high pH zones. Future work should be focused on the determination of mineralogical forms of As in volcanic ash and on detailed investigation on factors controlling As mobility. |
Keywords | arsenic; mobilization; Rio Dulce alluvial cone; Argentina; volcanic ash; sediments; adsorption; oxides |
Public Notes | Files associated with this item cannot be displayed due to copyright restrictions. |
Byline Affiliations | KTH Royal Institute of Technology, Sweden |
National University of Santiago Del Estero (UNSE), Argentina | |
Costa Rican Institute of Electricity, Costa Rica | |
Masaryk University, Czech Republic |
https://research.usq.edu.au/item/yy7vw/distribution-and-mobility-of-arsenic-in-the-r-o-dulce-alluvial-aquifers-in-santiago-del-estero-province-argentina
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