Sources and behavior of arsenic and trace elements in groundwater and surface water in the Poopó Lake Basin, Bolivian Altiplano
2012 (English)In: Environmental Earth Sciences, ISSN 1866-6280, Vol. 66, no 3, 793-807 p.Article in journal (Refereed) Published
Water management in semiarid and arid catchments such as the PoopÃ³ Lake Basin requires improved understanding of the complex behavior of the various contaminants, which affect the drinking water quality and considered as crucial for sustainable development of the region. Mechanisms of arsenic (As) release in the surface and groundwater were studied. Hydrochemical data for surface water (4 samples) and groundwater (28 samples) were collected in a small watershed in the PoopÃ³ catchment at the highland of the Bolivian Andes (Altiplano). All of them show high electrical conductivity values and moderately oxidizing conditions. The surface water contains high concentration of sulfate and the trace elements As, Zn and Pb in the zone affected by acid mine drainage. There is a large variability of the concentration of As and of the trace elements in the groundwater in the five different regions within the PoopÃ³ catchment. The metal concentrations sensitive to changes of redox state and results of speciation modeling suggest that As (V) is a predominant aqueous species, which conforms to the prevailing oxidizing conditions in the shallow groundwater environment. Two generalized trends for As distribution were identified in groundwater: (a) high concentrations are found in the arid zone (100-250 ÎŒg/L) in the southern (region III) and in the northwestern (region V) regions, and (b) low concentrations (< 50 ÎŒg/L) are found in the remaining part of the basin (region I, II and IV). However, the spatial distribution within these regions needs to be investigated further. A conclusion from the present study is that there are multiple sources of As as well as other trace elements (such as Cd, Mn and Zn) in the PoopÃ³ Lake Basin. Among the sources and the processes which led to the mobility of As and other trace metals in the region are: (a) weathering of sulfide minerals, (b) oxidation of pyrite and/or arsenopyrite in mineralized areas and (c) desorption from hydrous ferric oxide (HFO) surfaces. In non-mining areas, volcanic ash is suggested to be a significant source of As.
Place, publisher, year, edition, pages
2012. Vol. 66, no 3, 793-807 p.
Altiplano, Arsenic, Bolivia, Drinking water quality, Groundwater, Hydrochemistry, Mobilization, Trace elements
Earth and Related Environmental Sciences
IdentifiersURN: urn:nbn:se:kth:diva-96040DOI: 10.1007/s12665-011-1288-1ISI: 000304624100010ScopusID: 2-s2.0-84861182279OAI: oai:DiVA.org:kth-96040DiVA: diva2:529714
QC 201205312012-05-312012-05-302015-05-29Bibliographically approved