Assessment of contamination level of a Tanzanian river system with respect to trace metallic elements and their fate in the environment

dc.creatorGebreyohannes, Netsanet
dc.creatorRwiza, Mwemezi
dc.creatorMahene, Wilson
dc.date2022-09-22T09:11:28Z
dc.date2022-09-22T09:11:28Z
dc.date2022-04-01
dc.date.accessioned2022-10-25T09:24:33Z
dc.date.available2022-10-25T09:24:33Z
dc.descriptionThis research article was published by IWA Publishing, 2022
dc.descriptionThe quality of water and sediments from a marginally-studied river was investigated with respect to As, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn including their fractionation behavior and environmental risk. Samples were collected along the Kou River that flows across two districts in the Manyara region of Tanzania. The leaching behavior of Fe was studied using sequential extraction fractionation and kinetics approach. The Kou water failed to meet the irrigation, aquatic, and biological life standards with respect to one of more trace metallic elements (TMEs). Fe concentration in the river water ranged from 4.1 to 5.38 mg/L, exceeding all the three standards. Six pollution indices were applied to assess the contamination and ecological risks of the nine trace metallic elements in the sediments. Overall, the metals were found to moderately contaminate the sediments. Cr, Fe, and Mn fell under the ‘severely polluted’ sediment quality class. Fe was the only metal that was found to significantly pollute both the river water and sediments. The Fe fractions in the sediments were in the order of residuals.Fe-Mn bound.or ganic bound.carbonate bound.water soluble.ion exchangeable; 7.8% of the total Fe content was bioavailable with a low potential to leach from the sediments. Under natural conditions, the sharpest release of the non-residual mobile fractions of Fe were identified to occur within the first 24 hours with the maximum Fe leached being 0.14% on the 12th day. None of the metals in the sediments were found with a poten tial to pose ecological risk
dc.formatapplication/pdf
dc.identifierhttps://doi.org/10.2166/ws.2022.002
dc.identifierhttps://dspace.nm-aist.ac.tz/handle/20.500.12479/1672
dc.identifier.urihttp://hdl.handle.net/123456789/95563
dc.languageen
dc.publisherIWA Publishing
dc.subjectEcological risk assessment
dc.subjectPollution indices
dc.subjectSequential extraction
dc.subjectTrace metallic elements
dc.subjectWater and sediment quality
dc.titleAssessment of contamination level of a Tanzanian river system with respect to trace metallic elements and their fate in the environment
dc.typeArticle

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