A study on the impact of physicochemical and hydrographic factors of water on the nutrients pollution in the sediments in the Karun River

Background: Water pollution from nutrients is a major environmental challenge. This study investigated the relationship between physicochemical and hydrographic components with nitrates and phosphates in the Karun River, Ahvaz. Methods: Forty samples were obtained from ۱۰ different areas from the northern regions of the river to the south of Ahvaz city in all four seasons of ۲۰۲۳, using the Peterson grab for sediments and a ۱-liter glass for water. The Hach Spectrophotometer (model DR۲۸۰۰, the United States) was used to measure nitrate and phosphate levels. River discharge was measured using the Guage method, evaporation rate was determined using the transpiration method, sedimentation rate was calculated using bathymetric maps, average friction was determined using the Chézy method, particle diffusion coefficient was calculated using the transverse method, and mass remaining rate was based on Yang’s wave movement equations. Results: The results showed that water quality characteristics such as biochemical oxygen demand (BOD), chemical oxygen demand (COD), dissolved oxygen (DO), turbidity, and total suspended solids (TSS) in the samples from the northern areas were significantly better than in samples from the lower areas. Nitrate levels ranged from ۲۱.۸۱ to ۲۳.۹۵ mg/L, and phosphate levels ranged from ۳.۳۷ to ۶.۷۶ mg/L. There was a significant correlation between river discharge, evaporation rate, sedimentation rate, mass remaining, particle diffusion coefficient, and phosphate levels (P < ۰.۰۵). However, no significant relationship was found between these parameters and nitrate levels. Conclusion: The findings are essential for understanding the relationship between hydrographic parameters and nutrient levels in water sources, which can lead to more effective environmental management strategies.

کلیدواژه ها:

Water quality ، Rivers ، Nitrate ، Phosphates ، Karun River