Unit:
Department of ChemistryLibrary of the School of Science
Author:
Tzempelikou Eleni
Dissertation committee:
Δρ. Χριστίνα Ζέρη, Διευθύντρια Ερευνών, Ινστιτούτο Ωκεανογραφίας, Ελληνικό Κέντρο Θαλασσίων Ερευνών
Ομότιμος Καθηγητής Εμμανουήλ Δασενάκης, Τμήμα Χημείας, Εθνικό και Καποδιστριακό Πανεπιστήμιο Αθηνών
Επίκουρος Καθηγητής Σωτήριος Καραβόλτσος, Τμήμα Χημείας, Εθνικό και Καποδιστριακό Πανεπιστήμιο Αθηνών
Καθηγητής Ευάγγελος Μπακέας, Τμήμα Χημείας, Εθνικό και Καποδιστριακό Πανεπιστήμιο Αθηνών
Δρ. Μανώλης Τσαπάκης, Διευθυντής Ερευνών, Ελληνικό Κέντρο Θαλάσσιων Ερευνών
Καθηγητής Σεραφείμ Πούλος, Τμήμα Γεωλογίας, Εθνικό και Καποδιστριακό Πανεπιστήμιο Αθηνών
Καθηγητής Βασίλειος Ρούσσης, Τμήμα Φαρμακευτικής, Εθνικό και Καποδιστριακό Πανεπιστήμιο Αθηνών
Original Title:
Trace metals in marine surface waters: inventory in the Greek seas, sources and processes with emphasis on the surface microlayer
Translated title:
Trace metals in marine surface waters: inventory in the Greek seas, sources and processes with emphasis on the surface microlayer
Summary:
The first part of the present study provides information on the distribution of trace metals in coastal and transitional surface waters of the Greek territory, based on a 6-year dataset. On the EU level, the WFD and the MSFD aim at progressive reduction of discharges of natural occurring priority substances, such as metals, in order to achieve ‘good chemical status’. It becomes important to assess background concentrations of metals (BAC) and discern their natural vs anthropogenic sources. The work contributes towards this direction by assessing the BAC values of Cd, Co, Cu, Ni, Pb, Zn and by classifying 70 waters bodies of Greece in relation to BAC. The number of water bodies with metals concentrations >BAC diminishes in the order of Ni>Cu>Pb>Co>Cd>Zn, showing that Ni and Cu contamination affects the highest number of water bodies. As a supplement to these results, an experimental work was designed to assess Cu release from marine point sources, aquaculture Cu-alloy nets and polymer nets with Cu-based antifouling paints, revealing a significant Cu environmental loading. The second part deals with Cd and Co dynamics in surface waters, including the sea surface microlayer (SML), in connection to wet deposition data during an annual cycle at Saronikos Gulf. Metals partitioning (labile, dissolved, and total fractions) was considered. Wet deposition Cd/Co ratios proved to be a clear fingerprint concerning their sources, Saharan dust vs anthropogenic. Both metals are significantly enriched in the SML in all their forms. The correlation analysis of Cd and Co with two groups of organic substrates, carbohydrates (i.e., dissolved carbohydrates and transparent exopolymer particles (TEPs)) and dissolved humic-like material (as defined by absorbance/fluorescence measurements) showed an affinity of total fraction of both metals to TEPs in the SML. Co was also well correlated with carbohydrates and humic-like material in the dissolved state. It is possible that the binding processes of Co continue in the particulate phase and result in the observed transformation of dissolved to particulate Co forms in the SML. Finally, the role of a ‘new’ substrate such as Polystyrene microplastics (MPs) on Cu binding in the SML was explored during a mesocosm experiment, highlighting their importance in metal cycling.
Main subject category:
Science
Keywords:
dissolved Cd, Co, Cu, Ni, Pb, Zn, background levels, SML, partitioning ratios, metal binding organic substrates
Number of index pages:
15-18
Number of references:
283
File:
File access is restricted until 2025-12-27.
PhD_Tzempelikou.pdf
5 MB
File access is restricted until 2025-12-27.
