Siby,Varghese; Chandramohanakumar, N(National Institute of Oceanography & CUSAT, 2003)
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Abstract:
Rare earth elements have occupied an important role in marine geochemical research, particularly as used in the format of REE abundance patterns to describe the geochemical pathways in marine sedimentation and authigenesis. This study concentrates on the distribution pattern of Rare earth elements in the sediments, behavior of Eu and Ce with respect to their occurrence in multiple oxidation states. It also concentrate the depth wise variation of sediment REEs from near shore areas (30m) to deeper depths 200m) in the Arabian Sea. It includes the downcore variation of REEs and other trace elements in the sediment cores and a comparison between the REE distributions of Arabian Sea sediment with the sediments of Andaman Sea. The study gives a general introduction regarding the importance of RRE studies, its occurrence and abundance, electronic configuration, lanthanide contraction, oxidations states and REE supply to the ocean, seawater and sediments.
Unnikrishnan,P; Dr.Muraleedharan Nair, S(Cochin University Of Science And Technology, December , 2000)
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Abstract:
Environmental persistence, fate and interactive effects with living
organisms - beneficial or toxic - of trace elements are directly related to the
physico-chemical forms in which they occur. Knowledge on the association of
trace metals with different environmental compartments in an aquatic system
are, therefore, essential for monitoring the trace metal pollution as well as
transport, fate and bio-geochemical cycles of trace metals. This thesis is a
modest attempt in assessing the trace metal levels and their behaviour in the
aquatic environment of Kuttanad, an aquatic system that is severely affected
by man's intervention on natural processes, by seriously evaluating the levels
of trace metals in dissolved and particulate phases and also in the different
chemical fractions of the sediments.
Description:
Department of Chemical Oceanography, School of Marine Sciences,
Cochin University of Science and Technology
Unnikrishnan,P; Muraleedharan, Nair S(Department of Chemical Oceanography, School of Marine Sciences, 2000)
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Abstract:
This thesis is a modest attempt in assessing the trace metal levels and their behavior in the aquatic environment of Kuttanad, an aquatic system that is severely affected by man’s intervention on natural processes, by study seriously evaluating the levels of trace metals in dissolved and particulate phases and also in the different chemical fractions of the sediments. Understanding of the distributions, variations and transfer processes of trace metals in different environmental phases in the backwaters of Kuttanad is vital for the assessment of the water pollution problems and study the ecology of the area which contributes 20% of the rice production in the State of Kerala. Kuttand is a low-lying, shallow bay formed as a result of geological uplift. The major economic activity is agriculture involving 40% of the population. About 1.5% of the people are engaged in aquaculture. The trace metal distribution in the Kuttand backwaters is considerably influenced by the tropical features of the location and by human activities including agricultural activities and construction of salinity barrier. In this study an attempt is made to differentiate the metals in the sediment into exchangeable, reducible and resistant fractions in the sediments.