Study on sediment quality parameters in the tributaries of the Sirvan River-Zhaveh Dam of Sanandaj (2020-2021)

The Zhaveh dam is located on the Sirvan River containing two main branches of Gaveh Rood and Qeshlaq. The dam was designed for industrial and agricultural use. Surface sediment samples were collected at 5 selected stations in the two branches of the Sirvan River, Qeshlaq and Gaveh, as well as in the dam reservoir. In this study, nine sediment parameters (different forms of nitrogen and phosphorus, TOC, pH, Eh) were investigated to determine the quality and the prediction of the eutrophication trend of the Zhaveh Dam. The quality of sediments in different stations showed that they contain high organic and mineral pollution. Based on the TOC% of the sediment, the region was considered as slightly to highly polluted, especially in stations 2 and 3, but station 4 (Gaveh Rood branch) was classified as moderate quality. The changes in the OPI and ONI indices and comparison with the organic index standard also indicated the high pollution of the sediments in this region. These conditions are due to the high mean concentration of total phosphorus (2075±178 mg/kg.dw) and bioavailable phosphorus (666±142 mg/kg.dw) in the rivers feeding the dam, which deal with a high risk of eutrophication. In addition, after the water intake of the Zhaveh Dam and the high concentration of organic and mineral pollutants during the retention time of the water, it will be difficult to control the eutrophication