Authors
1
Graduated(MSc)., Department of Geology, Faculty of Marine Natural Resources, Khorramshahr University of Marine Sciences and Technology, Khorramshahr, Iran
2
2. Assistant Prof. Department of Geology, Faculty of Marine Natural Resources, University of Marine Sciences and Technology, Khoramshahr, Iran
3
Associated Prof. Department of Geology, Faculty of Marine Natural Resources, Khorramshahr University of Marine Sciences and Technology, Khorramshahr, Iran
Abstract
Abstract
This study investigated heavy metal contamination in the sediments of the Dez River and analyzes related environmental indices and physicochemical parameters. For this purpose, 25 sediment samples were collected from a limited area of the Dez River, spanning from Cham Golak to Ziba Shahr in Dezful, and analyzed. The results indicated that the pH range of the sediments was between 7.23 and 8.05, with little effect on the concentration of heavy metals. Additionally, the organic matter content in the sediments ranged from 0.28% to 2.54%, with the highest values observed at upstream stations, likely due to the influence of urban sewage, agricultural runoff, and industrial activities. A comparison of the heavy metal concentrations in the sediments with the Earth's crust values showed that the concentrations of arsenic (1.1 mg/kg), bismuth (0.65 mg/kg), and copper (27.92 mg/kg) were higher than typical concentrations in the Earth's crust, while chromium and lead had lower concentrations than the global average. Statistical analyses, including Pearson's correlation coefficient, revealed a significant positive correlation (r = 0.786) between chromium and nickel, suggesting a common hydrocarbon-based source for these two elements. Cluster analysis further indicated that stations with lower pollution, located downstream of the river with higher flow rates, were grouped separately. The results of this study highlight the varied impacts of pollutant sources on the concentration of heavy metals in the sediments of the Dez River. While some metals like copper and arsenic have significantly increased in the area, others like lead and chromium have lower concentrations compared to global averages. This could be due to the complex combination of pollutant sources, including agricultural, industrial, and urban activities. These findings suggest the influence of diverse pollution sources, including agricultural, industrial, and urban wastewater, on the heavy metal concentrations in the Dez River sediments.
Keywords
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