An experimental study of macro and micro elements in groundwater

The objective of this study was to evaluate and map regional patterns of two macro elements (Fe and Mn) and two micro elements (Pb and Cr), that all of these grouped as heavy metals, occurrence in ground water. The study was performed in Shush and Andimeshk plains in the south part of Iran, with high agricultural activities that cover an area of 1100 km2 between the Dez and Karkhe rivers. This region was divided into four sub-regions A, B, C and D. Additionally 168 groundwater samples were collected from 42 water wells during the months April, May, August and September of 2004. The Flame Atomic Absorption Spectrometry (AAS-Flame) was used to measure the heavy metals concentration in water samples. The results demonstrated that all of the samples, Fe and Cr concentrations have been shown below the WHO guidelines, but Mn and Pb contents of 7.1 and 40.5% of all samples was higher than WHO guidelines respectively. The Fe concentration is more pronounced in north part than southern part but groundwater Mn and Pb contents in south part is higher than northern part of studied area. The Cr contents of groundwater in studied area not follow particular pattern but its concentration was higher in sub-regions B and D compared to sub-regions A and C. Absent confining layers, proximity to land surface, excess agricultural and industrial activities in south part and groundwater flow direction that is generally from north to south parts in this area makes south region of Shush plain especially vulnerable to heavy metals pollution and other contaminants. © 2006 Asian Network for Scientific Information.