Ecology, Environment and Conservation Paper

EVALUATION OF HEAVY METALS CONTAMINATION IN SUSPENDED SEDIMENTS OF DIKRONG RIVER, ASSAM, INDIA

Satya Ranjan Goswami, B.J. Saikia, A. Goswami, A.J. Dev Sarma, Md. Y. Hassan and M. Buragohain

Abstract

This study is a comprehensive monitoring survey to assess the environmental pollution status of the river Dikrong -was carried out in 2020. Samples were taken at 10 different positions along the river from the foot hill of Arunachal Pradesh down to the Brahmaputra river. Besides other biological and chemical parameters, concentrations of Fe, Al, Ti, Pb, Zn, Cu, Ni, Co, Mn and Cr. Very high element concentrations were determined at only a few stations of the river Dikrong. The mean concentration exhibits positive correlations among Fe, Al, Ti, Mn, Zn, Pb, Ni, and Co. The relative distributions of the contamination are: Al > Fe > Ti > Mn > Cu > Cr > Zn > Pb > Ni > Co. An evaluation of the pollution status of the river was carried out by enrichment factors (EFs), contamination factors (CFs), geo-accumulation indexs (Igeo) and pollution load indexs (PLIs) calculated using adapted background concentrations of heavy metals in the sediments. The investigating factors suggest the significant contamination for Dikrong river sediments are Al and Fe. The mean concentrations of heavy metals in the sediments were found to be below the geochemical background level of world surface rock average. The elemental correlation is indicative to the metamorphosed pyrophanite (MnTiO3) deposition.