Assessment of heavy metal contamination and distribution in surface sediments of Karoun River, Panjoum Bridge to Farsit, using geochemical datas and statistical Analysis.

Rivers, as the living artery of the watershed, have played a decisive establishment of civilizations. But today, large amounts of pollutants enter the aquatic ecosystems, due to overpopulation and the expansion of industrial and agricultural activities. Among these, heavy elements are of special importance due to their stability, non-degradability, toxicity and bioaccumulation potential. Therefore, in this study, potential toxic elements ( AS, Cd, Cr, Ni, Cu, Pb, Zn) were investigated in order to determine the concentration, contamination factor and degree of contamination, geo-accumulation index, Enrichment and to detect the level of pollution caused by them. For this purpose, 21 surface sediment samples were collected based on the distribution of point and non-point pollution sources and river morphology. Samples were conditioned and concentration of toxic elements and sulfur were measured using ICP-MS at dry weight with accuracy of mg/kg and percentage of total organic carbon. Using enrichment factor and sediment quality standards (ISQGs, PEL, SEL), the level of contamination caused by toxic elements was detected. Hierarchical clustering analysis (AHC) with pearson similarity coefficient was used to identify metal elements with similar behavior in river sedimentary environments and the most important cationic adsorbent such as organic matter and clay particles using XLSTAT2018 software