Investigation of arsenic pollution in water resources of kazan basin (Ankara)

The aim of this study is to reveal the current situation of arsenic pollution and the mobilization mechanisms of arsenic in the water resources of Kazan Basin with hydrogeochemical studies. İn this study, samples were taken from the wells, springs and fountains in the area during wet and dry seasons in order to observe the seasonal changes. A total of 34 samples were collected in the dry period, and 25 samples were collected in the rainy period. Within the scope of hydrogeochemical studies, major anions, cations and trace elements were investigated and the hydrogeochemical characteristics of the region were revealed. Discharge rates of the fountains, electrical conductivity, pH, temperature, oxidation-reduction potential and dissolved oxygen contents of the samples were determined in situ. All of the results obtained were evaluated in the Phreeqc program, the charge balance errors of the analyses were calculated, and the saturation indices of the waters with respect to different minerals were determined. In addition, the results of the analysis were evaluated using different diagrams and water types and possible geochemical processes affecting water chemistry were determined. In all except for a few samples, arsenic concentrations are above 10µg/L, which is the limit value determined by the World Health Organization (WHO). The lithological units of the region, faults, climatic conditions of the region were examined and in the light of hydrogeochemical studies, the source of arsenic was found out to be geocenic and the mobility mechanism is found out to be related to the carbonate ions.