Contamination and ecological risk assessment of heavy metals in water and sediment from hubs of fish resource river in a developing country

Abstract

River water and sediment embody environmental characteristics that give valuable information about the eco-environment. Due to rapid unplanned urbanization and industrialization, the aquatic environment of any urban river can be seriously polluted by heavy metals. Four heavy metals (As, Cr, Cd, and Pb) were analyzed in surface sediments and water from the Kirtankhola River located in the coastal area of Bangladesh. The decreasing pattern of metals was observed as Cr > Pb > As > Cd in both water and sediment. The heavy metal ranges were 1.67–7.31, 12.64–45.69, 0.01–1.59, and 8.03–35.68 μg/L in the water and 2.09–6.89, 14.76–47.08, 0.01–1.77 and 6.37–41.43 mg/kg in sediments for As, Cr, Cd, and Pb. The number of metals tested in water samples surpassed the acceptable limits of drinking water quality, indicating that water from this river is not safe for drinking and cooking and could pose a risk to the riverine ecosystem. The pollution load index (PLI) values were close to one, indicating that the sediment of the study river was low contamination. Contamination factor (CF) has reported that As, Cd, and Pb have been moderate to extremely polluted by sediment samples and metals level implied that the condition is much alarming and probably severely affecting the aquatic ecology of this riverine ecosystem.

Keywords:

• Trace metals
• water
• sediment
• ecological risk
• Kirtankhola River

Acknowledgements

The authors would like to express their gratitude and integrity to the Chemistry Laboratory Quality Control (QC), Khulna, Bangladesh, the authority and staff members during the sample analysis for the provision of laboratory facilities and cooperation. In addition, we would like to thank Professor Dr. Mirza Hasanuzzaman, Department of Agronomy, Sher-e-Bangla Agricultural University, Bangladesh, for kindly assisting the members of the University of Science and Technology of Patuakhali, Bangladesh during the field sampling and for improving the manuscript.

Disclosure statement

The authors declare that they have no conflict of interest.

Additional information

Funding

The authors extend their appreciation to the Dean of Scientific Research at King Khalid University, Saudi Arabia for funding this work through the Research Group Project (Small Group) under grant number R.G.P.I/176/41. The authors are also grateful for support from the National Science and Technology Fellowship (NST-2014–15) from the Ministry of Science and Technology, The Government People’s Republic of Bangladesh.