Fariba Hedayatzadeh - a PhD Candidate of Environment, Department of Environmental Science, Faculty of Natural Resources and Environment, Malayer University, Malayer, Iran
Nasrin Hassanzadeh - Assistant Professor, Department of Environmental Science, Faculty of Natural Resources and Environment, Malayer University, Malayer, Iran

Background & Aims of the Study: The current study was designed to determine the quality of sediments in Karun in Ahvaz, Iran, according to aquatic pollution indices. Materials and Methods: The sediment samples were obtained from six river stations in summer and winter. The sediment samples were air-dried, sifted, homogenized, and stored in plastic bags, and the concentrations of metals were determined in the laboratory. Results: The obtained findings revealed that the mean concentrations of lead, zinc, chrome, and cadmium were 26.27, 72.36, 53.47, and 3.85 mg/kg dw in summer and 13.41, 59.54, 30.28, and 0.42 mg/kg dw in winter, respectively. According to the mean scores of the potential ecological risk index (PERI), in two seasons, the sediment enrichment with metals was observed in the order of Cd > Pb > Cr > Zn; however, according to biological toxicity test (the effects range-median quotient), the sequences of the metals during summer and winter were Cd > Cr > Zn > Pb and Zn > Cr > Pb > Cd, respectively. The comparison of indices between stations showed that in summer, stations 3 and 4 were medium-low priority side according to the mean effects range-median quotient (mERM-Q) and were reported with moderate ecological risk based on the PERI. In winter, stations 2 and 4 had a medium-low priority side and moderate ecological risk according to mERM-Q and PERI, respectively. The results of hazard quotient (HQ) and modified hazard quotient also showed that the HQ values of Pb and Zn (0.1

Sediment, Heavy metals, Potential Ecological Risk Index (R), Biological Risk Index (mERM-Q), Hazard quotient (HQ), Karun River