Document Type : Primary Research paper
Rivers and wetlands which act as natural absorbents and food filters are important aquatic ecosystems. Kashaf Rood River is a seasonal river in Khorasan Razavi province that has many branches such as Ferizi, Zoshk, Torogh, Kardeh and Radkan Rivers. The aim of this study was to evaluate the concentration and the source (natural and man-made) of heavy metals in surface sediments of Kashaf Rood River. The results showed that the organic part of man-made has no significant contribution to the distribution of Hg in the river while the sulphide part is distributed as the organic phase in the environment because of the very close similarity coefficient with organic part. For Cr the man-made part and organic part have a similarity with each other and have a weaker relation with exchange able and sulphide parts. The results on the Pb also showed that natural resources have no role in the release of Pb in river because its similarity to other parts is very low but it is identical to Cr in other parts. It also became clear that there is a significant difference at 99% level in all four stages of chemical methods for all three metals and also all stations except Pb in the exchangeable and sulphide stages. It was found that the Station4 (Hemat Abad) the highest concentration of Hg. Station5 (Alteimoor) has the highest concentration for Cr. Station2 (Parkand Abad) has the highest concentration of Pb.