Volume No. 9 Issue No.: 3A Page No.: 944-952 January-March 2015

 

SPECIATION OF HEAVY METALS IN SURFACE SEDIMENT OF THE BRAHMAPUTRA RIVER, ASSAM, INDIA

 

Das Pallavi*, Manish Kumar and Kali Prasad Sarma

Department of Environmental Science, Tezpur University, Napaam, Assam (INDIA)

 

Received on : October 22, 2014

 

ABSTRACT

 

The distribution of heavy metal in different chemical form in sediments of the Brahmaputra river, Assam, India has been studied using sequential extraction method. Twelve surface sediment samples were collected from upstream to downstream. Seven heavy metals (Fe, Mn, Cu, Ni, Pb, Co, Cr) were analysed in collected samples. In most cases the average heavy metal concentrations in sediments were below the standard Shale values. It was found that in downstream location the river get contaminated by certain metals. Source apportionment carried out using principal component analysis. Result suggests that Cu, Ni, Co, Cr attributed anthropogenic source of heavy metal. Common source are urban run, municipal sewage and industrial effluents. Fe and Mn act as scavenger of heavy metal in the river system. Metal enrichment show minimal to moderate contamination. Metal speciation result revealed that most of the metals are associated with residual fraction except Cu which indicates that these metals are immobile. The risk assessment code suggests low to medium risk for all heavy metal except Cu and Pb which show high risk

 

Keywords : Brahmaputra river, Sediments, Heavy metals, Sequential extraction, Industrial effluents

 

 

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