摘要

Lake sediments are major sink for carbon and trace elements. Lake water and sediments need to be monitored continuously for environmental and geochemical explorations. In the present study, sediment characteristics, source and distribution of trace metals (Fe, Mn, Cr, Cu, Ni, Co, Pb and Zn) of Yercaud fresh water lake sediments, South India, situated at an elevation of 1515 m asl is presented. Twenty-five surface sediments were collected covering the entire expanse of the lake in a gridded pattern. Detailed chemical analyses reveal the following decreasing order of elements: Fe > Cu > Cr > Mn > Zn > Ni > Co > Pb. Geoaccumulation index, enrichment factor, contamination factor and pollution load index were calculated to evaluate the ecological impacts of these trace metals in the sediments. The index calculation indicates that all the trace elements were derived from natural process, but there are indications of anthropogenic activities. The study area was found to be highly contaminated with Cu, moderately contaminated with Cr and Co, considerably contaminated with Pb, Zn and Ni, and uncontaminated with Mn. The spatial distribution of the trace elements supports the strong association of sediment fine fraction and organic matter. The statistical principal component analysis also confirms that the concentration of Cr, Cu, Fe and Mn was mainly derived from the natural weathering and non-point agricultural sources. Pb and Zn arise due to the confluence of sewage effluents, traffic and boat activities. These elements need to be further evaluated for pollution control and prohibiting further deterioration in the Yercaud Lake.

  • 出版日期2017-1