Abstract

Heavy metals are important inorganic pollutants that are entered to aquatic ecosystems by municipal, agricultural and industrial wastewater. Heavy metals can transport and accumulate throughout the food chain. Accumulation of heavy metals in organism's tissues is called biomagnification (1). These elements are not biodegradable, therefore we have to remove or immobilize them for cleaning up the polluted environment (2). In this research, macrophytes potential for remediating of Nickel by phytoextraction process was investigated. For this research, Phragmites australis and bottom sediments at 3 polluted stations and 1 control station in summer and winter seasons were sampled. Generally 72 macrophytes and 24 bottom sediment samples were taken. Preparing and chemical digestion was preformed according to the standard methods and Nickel concentration in samples was measured by using flame atomic absorption spectrophotometery.Then with utilizing Dunkan test and Varians Analysis (� precision), bioconcentration of nickel in the organs of studied macrophyte and sediment were compared by statistical tests. Samples analysis results in the summer season showed the average of nickel concentrations in sediments 42.25 (ppm) and roots and stems of phragmites australis respectively 27.5 (ppm) and 17.75 (ppm) were defined. Also in the winter season average of nickel concentrations in sediments, roots and stems of Phragmites sp., respectively 46.57 (ppm), 29.5 (ppm) and 23 (ppm) were determined. The achieved results demonstrated bed sediments of Shadegan International Wetland have nickel pollution and phragmites australis capable for phytoextraction and accumulation of nickel in the macrophyte organs.