Arsenic in groundwater and sediments in a loessic aquifer, Argentina

摘要

This work presents the results of a 70 m deep exploration borehole in Buenos Aires province, Argentina. The objective of this work was to establish the As content on groundwater and sediment of the Pampeano aquifer. Groundwater and sediment samples were collected with a sampling interval of about one meter. Thirty representative groundwater and sediment samples were analyzed. Bailed groundwater samples show As concentrations in the range of 8.3-69 (median 32 μg/L). In contrast, pumped groundwater samples showed a higher As content of up to 163 μg/L. Sediment analysis showed typical association of loessic sandy silts with several calcrete horizons. The sediments show As contents in the range 3.5-6.3 mg/kg, and it shows a good correlation with Fe-Mn, which is interpreted as associated to oxy-hydroxides.