Environmental risk assessment of heavy metals pollution in aquatic ecosystem—A case study: Sediment of Kor River, Iran

ABSTRACT

A comprehensive investigation of fractionation and environmental risk of nine heavy metals is carried out for 12 sediment samples collected from Kor River, Iran. For this purpose, the 5-stage sequential extraction method, along with individual contamination factor, global contamination factor, and Environmental Risk Index (ERI), is used. Total concentrations of Cr, Hg, Ni, and Zn were found to be beyond the threshold effect level. The results of fractionation patterns indicate that As, Cr, Ni, Pb, and Zn are mostly associated with Fe-Mn oxide fraction, organic fraction, and residual fraction, while Cd and Mo are predominantly associated with carbonate fraction. Cu and Hg are mostly associated with organic and exchangeable fractions. The results of ERI revealed High to Dangerous risks in 40% of Kor River stations. The applied approach in this study is beneficial to other environmental studies that require analysis of complex data.

KEYWORDS:

• sequential extraction
• fractionation pattern
• Environmental Risk Index
• Kor River

Acknowledgments

Thanks are extended to the research committee of Shiraz University for logistical support.

Funding

The authors would like to thank the Presidency of Islamic Republic of Iran National Elites Foundation and medical geology research center of Shiraz University for financial support.