engleski

Characterization of arsenic-contamina ted aquifer sediments from eastern Cro‐ atia by ion microbeam, PIXE and ICP-OES techniques

Groundwater arsenic contamination has been evidenced in eastern Croatia and hydrochemical results suggest that the occurrenc e of arsenic in the groundwater depends on the local geology, hydrogeology, and geochemical characteristics of the aquifer. In order to perform the sediment characterization and to i nvestigate arsenic association with the other elements in the sediments, 10 samples from two boreholes (PVc-3 and Gundinci 1) in eastern Croatia were analyzed using two techniques: PIXE (without sample pre-treatment) and ICP- OES (after digestion), as well by ion microbeam analyses. The results of the PIXE and ICP-OES techniques showed quite good agreement ; however, greater discrepancies were observed at the higher arsenic and manganese mass ratios. According to both techniques, higher As mass ratios were observed in the sediments from the PVc-3 core (up to 651 mg/kg and 491 mg/kg using PIXE and ICP-OES analyses respectively) than from the Gundinci 1 core ( up to 60 mg/kg using both techniques). Although arsenic association with Fe is expected, no correlation was observed. The microbeam analyses demonstrated that arsenic is associated with sulphides and iron in the most As-contaminated sample from the PVc-3 core, while this relationship was not evident in the most As- contaminated sample from the Gundinci 1 borehole.

arsenic; sediments; eastern Croatia; ion microbeam; PIXE; ICP-OES; acid digestion

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