Identifying Sources of Groundwater Salinization in Lenjanat Plain, Esfahan, Iran

For identifying sources of groundwater salinization in Lenjanat Plain, samples were seasonally collected from groundwater, surface water and industrial wastewater. The results of field and laboratory measurements show a gradual increase in major (Na, Ca, Cl, SO4) and minor (Li, Br, Sr، I, Ba، F, Si) elements through groundwater flow direction. Electrical conductivity varies between 561 and 11390 μS/cm. Chloride ion as an indicator of groundwater salinization, highly correlated with EC and elements Mg، Ca، Br and Sr. Certain ratios, saturation index and geochemical graphs indicate that both the dissolution of evaporation deposits (halite and gypsum) and cation exchange are the most important processes affecting the chemical composition of groundwater. Mass ratios of conservative elements Cl/Br for groundwater samples in Lenjanat plain range from 329 (at borders) to 4492 (the center of plain). These data confirm the reported Cl/Br ratios for groundwater affecting by the dissolution of evaporation deposits but overlap with range of Cl/Br ratios for domestic sewage effluent groundwater.