| Abstract |
Chromium is a heavy metal which occurs in various oxidation states (from -2 to +6). CrIII and CrVI are the two most stable species which dominate in the environment. Chromium in aquifer environments originate either from natural sources (erosion of rocks, wet and dry deposition), or anthropogenic activities (wastes of chemical or mechanical industry).
Hexavalent chromium and its compounds are classified as carcinogenic, teratogenic and toxic for reproduction, according to both the International Center Research of Cancer (IARC) and the REACH Regulation. World Health Organization (WHO) and Greek Legislation (98/83/ΕC) have established 50 μg/l as upper permissible limit of total chromium in drinking water. In the past few years the interest of scientists has focused on certain regions of Greece, such as Thebes, where drinking water contains increased concentrations of total chromium and CrVI.
The objective of this project is the speciation and total determination of chromium in samples of drinking water and groundwater which were collected from residences and drillings of regions of Thebes. A multiwall carbon nanotubes – COOH - MWCNTs-COOH column, which was connected with inductively – coupled plasma - mass spectrometry: ICP-MS, was used for chromium speciation. Furthermore, multi-element analyses has been conducted in order to check possible cross-correlations of other metals with chromium. The speciation and multielement results where interrogated in order to determine the source of Cr VI as being either natural or anthropogenic.
Measured CrVI concentrations were ranging from non-detected to 94.2 ± 3.5 ppb, while total chromium concentrations from non-detected to 103.9 ± 3.6ppb. Only one sample exceeded the upper established permissible limit for total chromium. Cross-correlations and geological settings of the area indicate that the chromium is naturally occurring in Thebes. However, additional studies are necessary in order to establish the natural or anthropogenic source of CrVI.
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Προσδιορισμός Cr(VI) στο πόσιμο νερό και η προέλευσή του
