Hydrogeochemical study of groundwater resources in Bostanabad plain using multivariate statistical methods

Shortage of surface water resources and excessive exploitation of groundwater resources in Bostanabad plain has caused a sharp decline in groundwater level and thus reduced its quality. The purpose of this study is to investigate the concentrations of major, minor and trace elements in groundwater resources with statistical methods. Therefore, 33 samples were collected for chemical analysis of major and minor ions and metalloid and heavy metals from spring and wells in the region. Physicochemical parameters of the samples were investigated using cluster and discriminant analysis and Pearson correlation coefficient. Using cluster analysis it was found that the samples are located in two clusters; cluster 1 belongs to the samples collected from East and Northeast of the area and is affected by Miocene evaporitic formations of the region, while cluster 2 is mainly related to the samples which is impacted from alluvial tuffs of the Sahand volcanic Mountain. Na, Mg, NO3, PO4 and SiO2 parameters were determined in 5 steps as the most appropriate parameter to predict clustering. Increasing salinity will be effective in increasing the mobility and release of manganese. The correlation between calcium, arsenic and iron showed that the sorption of arsenic to the surface of iron hydroxide increases in the presence of calcium. The relation between iron and manganese will be strong due to the common sensitivity to changes in oxidation-reduction potential, similar geochemical properties as well as the simultaneous presence of iron and manganese (hydro) oxides in the upper layer of soil.