investigation of aluminum, iron, manganese, chromium and cadmium concentrations in groundwater of oshnavieh plain

one of the most important issues in groundwater is its contamination by heavy metals. because of chemical stability and poor degradation of heavy metals and their ability to accumulate in living organism’s bodies, they can become toxic. for this, 15 water samples were collected from the groundwater resources of the oshnavieh plain in september 2015 ,with evenly distributed, and then were analyzed by atomic absorption. concentrations of aluminum, iron, manganese, cadmium and chromium and saturation indices for aluminum, iron and manganese were determined. the analysis results were compared with standard values of the world health organization using the arc gis software and phreeqc software for calculating saturation indices the results showed that in 33.33 percent of the samples only aluminum concentration is higher than the world health organization's maximum acceptable concentration and in the rest of samples concentrations of the metals are below the standard concentration. except aluminum, contaminations of the other heavy metals are not in risk boundary. but, because of the shallow groundwater depth and intensive agricultural activities in the plain, certainly in the long term it will be followed by many environmental risks. so, it is necessary that the groundwater resources of the aquifer should be considered for monitoring industrial wastewater, agricultural pesticides and irrigational returned water flow.