Geochemistry of Core Sediments from Tropical Mangrove Region of Tamil Nadu: Implications on Trace Metals

Abstract

The present study aims to determine the concentrations of certain trace metals (Fe, Mn, Cr, Cu, Pb, Zn, Co, Ni, Ba, Sr, V and Rb) and to identify the possible sources of the trace metals with multivariate analyses and assess the metal contamination using the enrichment factor (EF) and geo-accumulation index (I geo ) from the two core samples taken from Pichavaram lagoon. Pichavaram mangrove is a dynamic intertidal environment lying in between Vellar and Coleroon estuaries in Cauvery delta along the east coast of India. High OM in the present study is noted in both core samples which are mainly controlled by productivity and sediment texture. The increase of trace metals concentrations was observed at lower intersects which indicates that the trace metals were reprecipitated around the redox boundaries.Further it signifies that the enrichment of metals in C1 core sample is closely related to the diagenetic. Factor 1 with significant positive loadings on Mud and good loadings on Fe and Mn suggests the associations of these metals with finer sediment fractions and aluminosilicates. These elements to be enriched in the clay fraction in both core samples. They are mainly related to anthropogenic inputs and reflect the complexing nature of the organic matter. I geo studies confirm the contamination of the study area. Overall the study highlights significant anthropogenic contributions in terms of heavy metal pollution. Comparative data for normalized enrichment factors and the modified degree of contamination show that Pichavaram sediments have suffered significant systematic heavy metal contamination following catchment urbanization.

Heavy metal pollutants and their spatial distribution in surface sediments from Thondi coast, Palk Bay, South India

“…Multivariate analysis is commonly used to distinguish factors such the natural and anthropogenic contributions of the elements according to the various levels of relationship [17,18,[50][51][52]. In this study, PCA/FA was employed to ascertain possible relationships of the variables and their input sources among the pollutants.…”

Organic Carbon (OC) and Organic Matter (OM) in Sediments Collected from Two Wetlands in Central Bida Basin, Nigeria

“…Sediments samples were collected at intervals of 0.2 m from the top to the bottom (Kalaivanan et al, 2017) and on the observed physical changes in the sediments profile. Within the gridded cells, representative surface sediments samples were also collected within the wetlands.…”

Heavy metal pollutants and their spatial distribution in surface sediments from Thondi coast, Palk Bay, South India

“…Pearson's correlation analysis defines the relationship between the heavy metals and their major contributors in the environment [49][50][51]. Pearson's correlation coefficients for sand, mud, OM, Fe, Mn, Cr, Cu, Ni, Cd, Pb, and Zn components are shown in Table 7 & Figure 7.…”

“…Multivariate analysis is commonly used to distinguish factors such the natural and anthropogenic contributions of the elements according to the various levels of relationship [17,18,[50][51][52]. In this study, PCA was employed to ascertain possible relationships of the variables and their input sources among the pollutants.…”