Chemometric Study on the Trace Metal Accumulation in the Sediments of the Cochin Estuary-Southwest Coast of India

Department of Chemical Oceanography, School of Marine Sciences, CUSAT, Kochi, 682516, India, .
Environmental Monitoring and Assessment (Impact Factor: 1.68). 11/2011; 184(10):6261-79. DOI: 10.1007/s10661-011-2418-7
Source: PubMed


The distribution and accumulation of trace metals in the sediments of the Cochin estuary during the pre-monsoon, monsoon and post-monsoon periods were investigated. Sediment samples from 14 locations were collected and analysed for the metal contents (Mg, Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd and Pb), organic carbon, total nitrogen, total sulphur and grain size. The data were processed using statistical tools like correlation, factor and cluster analysis. The study revealed an enrichment of Cd and Zn in the study area particularly at station 2, which is confirmed by enrichment factor, contamination factor and geoaccumulation index. The factor analysis revealed that the source of Cd and Zn may be same. The study indicated that the spatial variation for the metals like Mg, Cr, Fe, Co, Ni, Cu, Zn, Cd and Pb were predominant unlike Mn which shows a temporal variation. The strong association of trace metals with Fe and Mn hydroxides and oxides are prominent along the Cochin estuary. The anthropogenic inputs of industrial effluents mainly control the trace metals enrichment in the Cochin estuary.

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    • "Lake sediments are generally recognized as a sink for many substances in aquatic systems and are also a potential source of dissolved and particulate-bound contaminants to overlying waters, resulting in adverse effects on aquatic ecosystems (Segura et al., 2006). Coal combustion, high-temperature processing of ores, and agricultural practices have been identified as input pathways of toxic metals for lake sediments (Dassenakis et al., 2003; Deepulal et al., 2012; Gao et al., 2005; von Gunten et al., 1997). Balogh et al. (1999) and Birch et al. (1996) pointed out that lake sediments can provide a stable archive of past and present inputs of trace metals to a lake, permitting reconstruction of the historical record. "
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    Full-text · Article · May 2015 · Journal of Geochemical Exploration
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    • "Heavy metals such as cadmium, lead, copper and zinc are principal pollutants of aquatic ecosystems because of their environmental persistence, toxicity and great potential of accumulation in the food chains [1,2,3]. They enter the aquatic system through river flow or atmospheric deposition, and can be transported to the sediments immediately through absorption and sedimentation processes by suspended matters [4,5]. Thus, sediments are recognized as important sinks of heavy metals and they reflect the quality of an aquatic system. "
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    ABSTRACT: The distribution and accumulation of the rare earth elements (REE) in the sediments of the Cochin Estuary and adjacent continental shelf were investigated. The rare earth elements like La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu and the heavy metals like Mg, V, Cr, Mn, Fe, Cu, Zn, U, Th were analysed by using standard analytical methods. The Post-Archean Australian Shale composition was used to normalise the rare earth elements. It was found that the sediments were more enriched with the lighter rare earth elements than the heavier ones. The positive correlation between the concentrations of REE, Fe and Mn could explain the precipitation of oxyhydroxides in the study area. The factor analysis and correlation analysis suggest common sources of origin for the REEs. From the Ce-anomalies calculated, it was found that an oxic environment predominates in all stations except the station No. 2. The Eu-anomaly gave an idea that the origin of REEs may be from the feldspar. The parameters like total organic carbon, U/Th ratio, authigenic U, Cu/Zn, V/Cr ratios revealed the oxic environment and thus the depositional behaviour of REEs in the region.
    No preview · Article · Oct 2012 · Journal of Earth System Science
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