Sources and behavior of arsenic and trace elements in groundwater and surface water in the Poopo Lake Basin, Bolivian Altiplano

作者：Ramos Ramos Oswaldo Eduardo; Fernando Caceres Luis; Ormachea Munoz Mauricio Rodolfo; Bhattacharya Prosun^*; Quino Israel; Quintanilla Jorge; Sracek Ondra; Thunvik Roger; Bundschuh Jochen; Eugenia Garcia Maria

来源：Environmental Earth Sciences, 2012, 66(3): 793-807.

DOI：10.1007/s12665-011-1288-1

• Bolivia
• Altiplano
• Groundwater
• Hydrochemistry
• Arsenic
• Trace elements
• Mobilization
• Drinking water quality

Water management in semiarid and arid catchments such as the Poopo 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 Poopo 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 Poopo 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 mu g/L) in the southern (region III) and in the northwestern (region V) regions, and (b) low concentrations (%26lt;50 mu g/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 Poopo 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) ox

• 出版日期2012-6