engleski

Characterization of the arsenic contaminated aquifer sediments by ion microbeam, PIXE and ICP-OES techniques

Groundwater arsenic contamination has been evidenced in Eastern Croatia and hydrochemical results suggested that the occurrence of arsenic in the groundwater depends on the local geology, hydrogeology, and geochemical characteristics of the aquifer [1]. In order to perform the sediment characterization and to investigate arsenic association with the other elements in the sediments, 10 samples from boreholes (PVc-3 and Gundinci 1) in Eastern Croatia have been analyzed by ion microbeam analyses as well by two techniques: PIXE (without sample pre-treatment) and ICP-OES (after digestion). The samples have been air-dried and sieved through the sieve of the pore size of 0.065 mm. The results of the PIXE and ICP-OES techniques showed quite well agreement, however higher discrepancies have been observed at the higher arsenic and manganese mass ratios. Results showed that deeper sediments are more contaminated by arsenic, however according to both techniques higher As mass ratios have been observed in the sediments from PVc-3 core (up to 651 mg/kg and 491 mg/kg by PIXE and ICP-OES analyses respectively) than from Gundinci 1 core (up to 60 mg/kg by both techniques). The manganese concentrations have been similar in the samples from both cores, while Fe mass ratio has been higher in the samples from Gundinci 1 core. Although arsenic association with Fe is expected no correlation has been observed. Moreover, the microbeam analyses allowed recognizing of the fact that arsenic is associated mainly with sulphides in the samples from PVc-3 core, while this relationship was not evidenced by these analyses of the samples from the core Gundinci 1.

characterization of the arsenic

nije evidentirano