TY - JOUR
T1 - Geochemistry of naturally occurring arsenic in groundwater and surface-water in the southern part of the Poopó Lake basin, Bolivian Altiplano
AU - Ormachea Muñoz, Mauricio
AU - Garcia Aróstegui, José L.
AU - Bhattacharya, Prosun
AU - Sracek, Ondra
AU - Garcia Moreno, Maria E.
AU - Kohfahl, Claus
AU - Quintanilla Aguirre, Jorge
AU - Hornero Diaz, Jorge
AU - Bundschuh, Jochen
N1 - Publisher Copyright:
© 2016
PY - 2016/8/1
Y1 - 2016/8/1
N2 - Groundwaters from shallow aquifers and surface water from rivers of the southern part of Poopó Lake basin within the Bolivian Altiplano have significant quality problems such as high salinity and high concentrations of arsenic (As). The extent of As contamination is observed in the studied groundwater over large parts of the study area. Surface-waters are generally alkaline (pH 8.2–8.7) and oxidizing with dissolved oxygen (DO) concentrations in a range of 2.5–6.6 mg/L The water chemistry is predominantly of Na–Cl–HCO3–type, with concentrations of dissolved As in the range of 8.6–117 µg/L with As(V) as the main aqueous species. The concentration of Li varies in the range of 1.1–4.4 mg/L, while other trace elements occur in low concentrations. Groundwaters have a very large range of chemical compositions and the spatial variability of As concentrations is considerable over distances of a few km; dissolved As in groundwater spans over 4 orders of magnitude (3–3497 µg/L), while concentrations of Li have a range of 0.05–31.6 mg/L. Among the investigated drinking-water wells, 90% exceed the WHO guideline value of 10 µg As/L. Electrical conductivity ranges between 295 and 20,900 µS/cm; high salinity is resulting from evaporation under ambient semi-arid climatic conditions. The pH values of the groundwaters are generally slightly alkaline (5.5–8.7) and universally oxidizing, under these conditions As(V) is the prevalent specie. Groundwater As correlates positively with pH, electrical conductivity, Cl−, Na+, HCO3−, Ca2+ and SO42−. Weathering/dissolution of carbonates, evaporites, halite and plagioclase minerals incorporate Na+ and HCO3− in solution with consequent pH and alkalinity increase; these are favorable conditions for high mobility of As species. Stable isotopic signatures indicate recharge at the Altiplano with seasonal effects. All surface water and some groundwater samples are enriched due to evaporation, which probably increased concentration of dissolved As.
AB - Groundwaters from shallow aquifers and surface water from rivers of the southern part of Poopó Lake basin within the Bolivian Altiplano have significant quality problems such as high salinity and high concentrations of arsenic (As). The extent of As contamination is observed in the studied groundwater over large parts of the study area. Surface-waters are generally alkaline (pH 8.2–8.7) and oxidizing with dissolved oxygen (DO) concentrations in a range of 2.5–6.6 mg/L The water chemistry is predominantly of Na–Cl–HCO3–type, with concentrations of dissolved As in the range of 8.6–117 µg/L with As(V) as the main aqueous species. The concentration of Li varies in the range of 1.1–4.4 mg/L, while other trace elements occur in low concentrations. Groundwaters have a very large range of chemical compositions and the spatial variability of As concentrations is considerable over distances of a few km; dissolved As in groundwater spans over 4 orders of magnitude (3–3497 µg/L), while concentrations of Li have a range of 0.05–31.6 mg/L. Among the investigated drinking-water wells, 90% exceed the WHO guideline value of 10 µg As/L. Electrical conductivity ranges between 295 and 20,900 µS/cm; high salinity is resulting from evaporation under ambient semi-arid climatic conditions. The pH values of the groundwaters are generally slightly alkaline (5.5–8.7) and universally oxidizing, under these conditions As(V) is the prevalent specie. Groundwater As correlates positively with pH, electrical conductivity, Cl−, Na+, HCO3−, Ca2+ and SO42−. Weathering/dissolution of carbonates, evaporites, halite and plagioclase minerals incorporate Na+ and HCO3− in solution with consequent pH and alkalinity increase; these are favorable conditions for high mobility of As species. Stable isotopic signatures indicate recharge at the Altiplano with seasonal effects. All surface water and some groundwater samples are enriched due to evaporation, which probably increased concentration of dissolved As.
KW - Altiplano
KW - Arsenic
KW - Bolivia
KW - Drinking water quality
KW - Geochemistry
UR - http://www.scopus.com/inward/record.url?scp=84979665772&partnerID=8YFLogxK
U2 - 10.1016/j.gsd.2016.04.002
DO - 10.1016/j.gsd.2016.04.002
M3 - Artículo
AN - SCOPUS:84979665772
SN - 2352-801X
VL - 2-3
SP - 104
EP - 116
JO - Groundwater for Sustainable Development
JF - Groundwater for Sustainable Development
ER -