Dispersion and Accumulation Trend of Heavy Metals in Coastal and Estuarine Sediments and its Textural Characteristics, a Case Study in India

Evaluation of metal enrichment and trophic status on the basis of biogeochemical analysis of shelf sediments of the southeastern Arabian Sea, India

“…The accumulation process is more intense in silt and clay fractions rather than the sand dominated regions as the negatively charged clay minerals and organic components adsorb positively charged metal ions. The Cochin transect showed metal accumulation, which is in agreement with earlier studies by Sudhanandh et al (2011) and Balachandran et al (2003). Usually, the anthropised coastal margins compared to other offshore stations are subjected to extreme stress from different pollution sources.…”

“…These include studies on labile organic matter (Gonsalves et al, 2011) and trace metal concentrations (Laluraj and Nair, 2006). A few studies deal with the recent trends in the biogeochemical features of the southeastern Arabian Sea (Jacob et al, 2009;Sudhanandh et al, 2011;Manju and Sujatha, 2012). The distribution of C, N, H and S contents in the southeastern Arabian Sea is poorly understood and little is known about the trophic status and origin of sedimentary organic matter (Balachandran et al, 2003).…”

Lead distribution in coastal and estuarine sediments around India

“…The median concentration of Pb in estuarine and coastal sediment from this region was 33.3 mg kg À1 (Table 8). The total concentration of Pb in the sediments were found to vary from 0.15 to 176.87 mg kg À1 (Balachandran et al, 2006;Kumar and Edward, 2009;Sudhanandh et al, 2011;Martin et al, 2012;Nair and Ramachandran, 2002;Dipu and Kumar, 2013;Selvam et al, 2012). The highest concentration of Pb in sediment has been reported in Manakudy estuary (Kumar and Edward, 2009) and the lowest concentration of Pb has been found in the coastal sediments from this region (Nair and Sujatha, 2012).…”

“…However, very high enrichment of Pb (EF $ 9) in some estuarine sediment has been attributed to the point sources (anthropogenic influence). Sediments belong to this area was mostly rich in organic carbon (Balachandran et al, 2006;Kumar and Edward, 2009;Sudhanandh et al, 2011;Martin et al, 2012;Nair and Ramachandran, 2002). It has been reported that suboxic environment of the overlying water column specially in the continental self of this region preserves carbon content in the bottom sediment (Martin et al, 2012;Balachandran et al, 2006).…”

Evaluation of heavy metal enrichment in Cochin estuary and its adjacent coast: multivariate statistical approach

“…This also indicated that the significant role of hydrous Fe oxides and mud (silt and clay) might be playing in controlling the distribution of other heavy metals in the study area. Negative relationship observed between Fe and Mn also implied that they had entirely components indicated the association of these metals with organic components in the sediments of Cochin estuary (Shajan 2001;Balachandran et al 2005;Sudhanandh et al 2011;Deepulal et al 2012). PC1 could be considered as the granulometric component which stands for the sorption/desorption of metals on the fine-grained minerals, organic matter and geochemical phases like Fe-Mn oxyhydroxides.…”