Heavy Metal Contamination Assessment of Groundwater Resources in Behbahan Plain Southwest Zagros

Abstract

Ground water is an important issue in environmental engineering and water supply systems, so preservation and purification of ground water have a critical role in any community. This paper investigates the concentration of several elements such as Pb, Cd, As, Se, Co and Zn for ground water in Behbahan (a city in southwest of Iran), to this purpose a group of 30 wells were studied to determine the heavy metal concentration, physical parameters (PH, EC, TDS, Temperature) in situ . The major ions’ values of HCO 3 -2 , SO 4 2- , Cl - , Na + , Mg 2+ , Ca 2+ , K + were measured for the wells based on the titrimetrical and flame photometry and optical emission spectrophotometer. Results of the analyses indicated the concentration of Pb, As, Cd and Se in 33, 13, 56, 100 percent greater than normal range of WHO standard respectively. No pollution of Co and Zn was seen in any specimen. There is a low correlation between Pb and major ions value, so it can be concluded that Pb overconcentration is caused by human contamination. The high correlation between Se, As and major cations and anions, implies that they can originate from dissolution and liquidation of mineral evaporation in the zone. The high rate of Cd concentration in urban sewage water is due to the small industries, workshops and mills wastewater.