Supervisors info:
Μαρία Οικονόμου (Καθηγήτρια) Επιβλέπουσα, Στυλιανός Λόζιος (Επίκουρος Καθηγητής), Ιωάννης Μήτσης (Λέκτορας)
Summary:
Varnavas’ basin finds in the SE Attica. It begins from the tops Pothes and
Samari and leads to the SE department of Marathona’s lake. The bigger part is
covered by river-floods depositions (Kapandriti’s shaping) and in SE region are
presented the travertinoid limestones (Kalamo’s shaping). Because of the
intense tectonic (E-W direction) is presented the transformed background in the
Lakka’s stream. Travertinoid limestones were created in lacustrine environment
in Upper Miocene from detritus.
The object of present postgraduate work is the investigation of geochemical
contamination in the travertinoid limestones in Varnavas’ basin, the
determination of hosts As and metals and calculation of factor of
bioaccumulation of trace elements. The objective of this research is to
estimate the size of contamination at the carbonic basin and investigate the
possible origin. So that it contributes the local authorities to receive the
necessary measures, to protect the health of citizens and the environment.
The geochemical research was focused on the determination of As, Mo, Cu, Pb,
Zn, Mn, Fe, Sb, Hg in the ground and the plants. The samples were received
mainly from the quarry of Varnavas and also from Ntrazaiza and Pourithi. The
results of chemical analyses of Varnavas’ basin were compared with samples of
ore from the mines in Grammatiko and Lavrion. The soil of quarry presents
interim content of the elements Fe, As, Zn, Sb, Hg, Pb, Cu compared with
Grammatiko’s ore and travertinoid limestone.
In Varnavas’ basin it was observed that As is increased with range between 33
and 430 ppm. The content of As was increased in the quarry of Varnavas, where
the rates of heavy elements in the ground is 1% As, 2% Mn, 1% Zn and 96% Fe.
The average content of soil in organic matter in the Quarry was determined in
1.2%. The tectonism (direction E-W) probably contributed in the transport of
As in the basin of travertinoid limestones’ formation, where As has been
deposited via the adsorption of Fe-hydroxides. The pH of the ground is alkaline
(pH=8.1), therefore As is rather found in the form As5+.
Due to the limits of phytotoxicity (Kabata-Pendias A, Pendias H, 2001) the
element As is presented in toxic levels for the plants. The indicator of bio-
accumulation presents intermediate degree of accumulation in Mn, Cu, Zn, Pb, Sb
and small in As, Fe. It is observed that Mo presents the biggest accumulation
in the plant.
The correlation analysis of soils respectively with plants and roots showed
that increasing the content of soil in As, the elements As, Mn, Sb are
accumulated more in the root than in the shoot.
Keywords:
Arsenic, Varnavas’ basin, Travertinoid limestone, Fe - oxydroxide, Fe-Mn ore
