The contamination appraisal and depthwise scrutiny of trace elements in sediments of the Moyur river, Bangladesh

Abstract

Trace element pollution in river sediments from multiple sources can pose ecological risks to aquatic systems. Therefore, the evaluation of elemental contamination and ecological risks in sediments is important for the proper management of a river system. In this study, concentrations of 12 major and trace elements (Cr, Mn, Fe, Al, Br, Rb, V, Co, As, Ta, Th, and U) were measured in sediments of the Moyur River, Bangladesh using neutron activation analysis technique. It is observed that concentrations of As, Br, Rb, Ta, Th, and U are higher than those of the upper continental crustal average values. Different environmental contamination indicators suggest that Moyur River sediments are heavily contaminated by Br. The pollution load index derived from the contamination factor also indicate the deteriorating condition of the sediments at different sampling points of the river. The depth-wise variation of the trace elements elucidates their contamination profiles along the sediment cores. An ecological risk assessment by different ecological risk factors and sediment quality guidelines indicates that sediments of the Moyur River are subjected to ecological risk by Cr and As. The multivariate statistical analyses indicate the origin and transport behavior of the studied elements in the sediments of the river. This study will provide baseline elemental concentration data for future monitoring of the contamination and to develop effective pollution control strategies for this urban river.

Keywords

• Sediment contamination
• Trace element
• Ecological risk
• Depth-wise variation
• Neutron activation analysis
• Moyur river