A CORRELATION STUDY OF MAJOR AND TRACE ELEMENTS IN SEDIMENTS OF RIVER NESTOS, NORTHERN GREECE AND COMPARISON WITH OTHER FLUVIAL SYSTEMS

ABSTRACT Fourteen sediment samples from the banks of River Nestos, Northern Greece, were collected, extracted with HNO 3 and analyzed for their content in 10 major and 32 trace elements. The analytical techniques used were ICP-OES and ICP-MS. The calculation of the Pearson Correlation Coefficient amongst the analyzed elements has revealed that among the majority of the elements exist positive correlations, which explains why most of them have a similar distribution along the river course. A comparison between the results acquired for the River Nestos and other fluvial systems, national and international, has shown the similarity of the geochemical identity of the River Nestos sediments with these systems

Environmental geochemical study of soils and sediments in coastal areas, east of Kavala and production of geochemical maps via the use of GIS

For the needs of the present dissertation a total of 65 surface soil samples, 8 surrounding rocks and 9 sea sediments, was collected from the area of the city of Kavala, northern Greece. The treatment of the samples took place at the Aristotle University of Thessaloniki, Faculty of Sciences, School of Geology, Department of Mineralogy-Petrology-Economic Geology, while the analyses were performed at the Faculty of Geology of the University of Barcelona, the SCT-UB (Scientific Technical Services of the University of Barcelona), and the ICTJA-CSIC (Institute of Earth sciences “Jaume Almera” - Spanish Council for Scientific Research), Barcelona (Spain) by the writer of the present PhD Thesis. The study area of the present Thesis was the city of Kavala (western Macedonia Greece), its industrial zone and the area surrounding them. The main industrial activities were the Phosphoric Fertilizer Industry (P.F.I.) and the Kavala Oil land facilities. Other human activities that took place in the area were the Xifias Fishery, some small enterprises that commerced the marbles that are present in the area, the extensive cultivation of large areas and the uncontrolled disposal of several types of solid and fluid wastes at the eastern part of the study area. For the extraction of the elements analytical quality HNO3 was used. Its purpose was to find the environmentally available portion of the concentration of the elements analyzed and not to attack the portion that is bind to alumino-silicate structures. The results showed that this method is an adequate alternative to other popular dissolution techniques, such as Aqua Regia, USEPA method 3051b and others. Forty two elements (Al, Ca, Cl, Fe, K, Mg, Na, P, S, Si, Ag, As, B, Ba, Cd, Ce, Co, Cr, Cs, Cu, Ga, Ge, Hg, La, Li, Mn, Mo, Ni, Pb, Rb, Sb, Se, Sn, Sr, Th, Ti, U, V, W, Y, Zn and Zr) were analyzed using ICP-OES and ICP-MS. These methods represent two of the most powerful, modern analytical techniques, with multielemental analyses capabilities, fast output of the results and really low detection limits, especially for ICP-MS. The treatment of the data included the comparison of the concentrations of the elements analyzed in the present dissertation with other, known concentrations of soils, with internationally accepted guidelines (e.g. The New Dutch List), with the surrounding rocks of the study area and others. Furthermore, the data of the surface soil samples were treated statistically with normal and log-normal probability plots, with the aid of which the “natural geochemical background” of the surface soils of the study area was estimated. Also, the Pearson correlation coefficient (r) was calculated for the surface soil samples. The treatment of the surrounding rocks and the sea sediment samples was similar, with the exception of the statistical treatment. During the present dissertation Geographic Information Systems (G.I.S.) were used and the analyses results were digitized. Moreover, the results of the statistical treatment of the surface soils data were incorporated into the digitization process and 42 geochemical maps were produced (one for every element analyzed). These maps are presented in Chapter 6, as well as in the CD that accompanies the present Thesis (along with other 261 maps). From the treatment of the data it is concluded that: The surrounding rocks of the study area (especially the marbles) contain some elements (i.e. Cl, Ag, Cd, Co, Hg, Se, W) that could be considered as enriched. This could mean that, under certain circumstances (e.g. high presence of Al minerals or organic matter) these rocks could provide the topsoils of the study area with these elements. However, the elements that are found enriched in the topsoils of Kavala area (i.e. As, Pb, Zn) are not found with extremely high values in the surrounding rocks. As possible source of these elements could be considered the various widespread PBG sulfide occurrences, but these occurrences are a little far from the area where the samples with the largest values are encountered. Regarding the surface soils, the elements analyzed could be divided into two groups, those that owe their concentrations to geological reasons and those that, possibly, owe their concentrations (at least a small portion of the analyzed samples) to both geological reasons and anthropogenic activities. The elements of the first group are Al, Ca, Fe, Mg, Si, Ce, Co, Ga, Ge, La, Li, Mn, Rb, Sb, Se, Sn, Sr, Ti, W, Y and Zr. The rest of the elements (Cl, K, Na, P, S, Ag, As, B, Ba, Cd, Cr, Cu, Hg, Mo, Ni, Pb, Sn, Th, U, V and Zn) belong to the second group. The element that seems to have the highest enrichment factor is As and is followed by Pb, Zn and the rest of the elements of the second group. The use of normal and log-normal probability plots has proved very effective in the defining of the natural geochemical background of the surface soils in the study area. Regarding the sea sediments, the analyzed elements could, similarly to the topsoils, be classified into two groups. In the first group belong Ca, Si and Sr, which owe their concentrations, mainly, to geological factors. The rest of the elements belong to the second group and owe their extreme concentrations at least, for certain samples, mainly to the anthropogenic activities that take place in the study area. These elements could, further, be separated into three, new groups, which link them to a certain activity. Thus, P, Ag, As, Ba, Cd, Ce, Cu, Hg, Mo, Se, U, Y and Zn owe their high values to the activities of the Phosphoric Fertilizer Industry (P.F.I.). The elements Κ, Β, Cs, and Rb show their extreme concentrations in front of the area where the Kavala Oil land facilities, the Xifias Fishery and the uncontrolled landfill areas are present. Finally, Fe, Mg, Cs, Ga, Ge, La, Li, Mn, Pb, Rb, Sb, Ti and Zr seem to owe their high concentrations to a combination of the anthropogenic activities of the area and for some of them (i.e. Fe, Mn), also to geological reasons. The samples (SS100 and SS108) with the highest concentrations are found in front of the main activities of the study area (P.F.I.) and the elements that seem to have the highest enrichment factors are Cd, As, Cu and Pb. The methodology that was followed in the present PhD Thesis (extraction with HNO₃, analyses with ICP-OES and ICP-MS, use of normal and log-normal probability plots, use of GIS) has proved that could be applied, with fairly good results, to environmental, geochemical studies of soils and sediments.Στην παρούσα Διδακτορική Διατριβή πάρθηκαν συνολικά 65 δείγματα επιφανειακών εδαφών, 8 δείγματα πετρωμάτων και 9 δείγματα θαλασσίων ιζημάτων από την ευρύτερη περιοχή της Καβάλας. Η προετοιμασία των δειγμάτων (ξήρανση, κονιοποίηση, κοσκίνισμα) έγινε στο Αριστοτέλειο Πανεπιστήμιο Θεσσαλονίκης, Σχολή Θετικών Επιστημών, Τμήμα Γεωλογίας, Τομέας Ορυκτολογίας-Πετρολογίας-Κοιτασματολογίας και οι αναλύσεις των δειγμάτων πραγματοποιήθηκαν στην Σχολή Γεωλογίας του Πανεπιστημίου της Βαρκελώνης (Faculty of Geology of the University of Barcelona), στο εργαστήριο SCT-UB (Scientific Technical Services of the University of Barcelona) και στο ινστιτούτο ICTJA-CSIC (Institute of Earth sciences “Jaume Almera” - Spanish Council for Scientific Research), Barcelona (Spain), από τον συγγραφέα της παρούσας Διατριβής. Η περιοχή μελέτης της παρούσας Διατριβής περιελάμβανε την πόλη της Καβάλας, τη βιομηχανική της ζώνη και άλλες περιοχές γύρω από τις προηγούμενες τοποθεσίες. Οι κύριες βιομηχανικές δραστηριότητες της περιοχής μελέτης ήταν η Βιομηχανία Φωσφορικών Λιπασμάτων (Β.Φ.Λ.) και οι χερσαίες εγκαταστάσεις της Kavala Oil, ενώ άλλες ανθρωπογενείς δραστηριότητες ήταν αυτές του Ιχθυοτροφείου Ξιφίας, μικρών επιχειρήσεων που εκμεταλλεύονταν τις εμφανίσεις μαρμάρου στην περιοχή, η εντατική καλλιέργεια μεγάλων τμημάτων στην περιοχή και η ανεξέλεγκτη διάθεση απορριμμάτων σε διάφορες περιοχές στο ανατολικό τμήμα της περιοχής μελέτης. Η διαλυτοποίηση των δειγμάτων έγινε με τη χρήση αναλυτικής ποιότητας ΗΝΟ₃. Σκοπός ήταν να παρθεί η περιβαλλοντικά διαθέσιμη ποσότητα κάθε στοιχείου και όχι αυτή που συνδέεται με τις αργιλοπυριτικές δομές. Όπως αποδείχθηκε αποτελεί μια πάρα πολύ καλή λύση για περιβαλλοντικές, γεωχημικές μελέτες εδαφών-ιζημάτων, η οποία δίνει παρόμοια αποτελέσματα με άλλες, ευρέως χρησιμοποιούμενες τεχνικές διαλυτοποίησης, όπως η Aqua Regia και η μέθοδος 3051b της USEPA. Οι αναλυτικές τεχνικές που χρησιμοποιήθηκαν ήταν οι ICP-OES και ICP-MS και με τη βοήθειά τους συγκεντρώθηκαν δεδομένα για 42 στοιχεία (Al, Ca, Cl, Fe, K, Mg, Na, P, S, Si, Ag, As, B, Ba, Cd, Ce, Co, Cr, Cs, Cu, Ga, Ge, Hg, La, Li, Mn, Mo, Ni, Pb, Rb, Sb, Se, Sn, Sr, Th, Ti, U, V, W, Y, Zn και Zr). Πρόκειται για δύο από τις πιο ισχυρές, σύγχρονες, αναλυτικές τεχνικές, με δυνατότητες πολυστοιχειακών αναλύσεων, γρήγορη παροχή των αποτελεσμάτων και με πάρα πολύ χαμηλά όρια ανίχνευσης, ιδιαίτερα για τη μέθοδο ICP-MS. Η επεξεργασία των δεδομένων περιελάμβανε τη σύγκριση των δεδομένων της παρούσας Διατριβής με γνωστές συγκεντρώσεις και τον υπολογισμό των αντίστοιχων συντελεστών εμπλουτισμού (Σ.Ε.), τη σύγκρισή τους με διεθνώς αποδεκτές οδηγίες (π.χ. The New Dutch List), τη σύγκριση με τα πετρώματα της περιοχής μελέτης κ.ά. Ιδιαίτερα, τα δεδομένα που αφορούσαν τα επιφανειακά εδάφη επεξεργάστηκαν με τη χρήση στατιστικών μεθόδων. Αυτές ήταν η χρήση διαγραμμάτων πιθανοτήτων και η εύρεση των γραμμικών συντελεστών συσχετισμού. Με τη χρήση των διαγραμμάτων πιθανοτήτων είναι δυνατόν να βρεθεί το καλούμενο «φυσικό γεωχημικό υπόβαθρο» των επιφανειακών εδαφών της περιοχής μελέτης. Η επεξεργασία των δεδομένων των πετρωμάτων της περιοχής μελέτης και των θαλασσίων ιζημάτων ήταν παρόμοια με αυτή των επιφανειακών εδαφών, δίχως τη στατιστική τους επεξεργασία. Για την εκπόνηση της παρούσας Διατριβής χρησιμοποιήθηκαν Συστήματα Γεωγραφικών Πληροφοριών (Σ.Γ.Π.) και τα αποτελέσματα των αναλύσεων ψηφιοποιήθηκαν. Ιδιαίτερα για τα επιφανειακά εδάφη τα αποτελέσματα της στατιστικής τους επεξεργασίας με διαγράμματα πιθανοτήτων ενσωματώθηκαν στη διαδικασία ψηφιοποίησης και κατασκευάστηκαν 42 γεωχημικοί χάρτες (ένας για κάθε στοιχείο που αναλύθηκε). Αυτοί οι χάρτες παρέχονται στο Κεφάλαιο 6, καθώς και στο ψηφιακό δίσκο που συνοδεύει τη παρούσα Διατριβή (μαζί με άλλους 261 χάρτες). Η επεξεργασία αυτών των δεδομένων έδειξε ότι: Τα πετρώματα της περιοχής μελέτης (ιδιαίτερα τα μάρμαρα) περιέχουν ορισμένα στοιχεία (π.χ. Cl, Ag, Cd, Co, Hg, Se, W κα) με εμπλουτισμένες συγκεντρώσεις. Αυτό σημαίνει ότι, υπό ορισμένες συνθήκες, θα μπορούσαν να τροφοδοτήσουν τα εδάφη και ιζήματα της περιοχής με υψηλές ποσότητες από αυτά τα στοιχεία, ώστε αυτά να παρουσιάζουν υψηλές συγκεντρώσεις στην περιοχή μελέτης. Παρόλα αυτά, στοιχεία τα οποία βρίσκονται εμπλουτισμένα στα εδάφη της Καβάλας, π.χ. As, Pb, Zn, δεν φαίνεται να είναι εμπλουτισμένα στα πετρώματα της περιοχής. Ως πιθανή πηγή προέλευσής τους θα μπορούσαν να θεωρηθούν οι διάσπαρτες εμφανίσεις μεικτών θειούχων οι οποίες, όμως, βρίσκονται σε αποστάσεις σχετικά μακρινές από το κέντρο της περιοχής μελέτης της παρούσας Διατριβής, όπου και βρίσκεται η πλειοψηφία των δειγμάτων της. Για τα επιφανειακά εδάφη, τα στοιχεία που αναλύθηκαν μπορούν να χωριστούν σε δύο ομάδες, αυτά που οφείλουν τις συγκεντρώσεις τους σχεδόν αποκλειστικά σε γεωλογικά αίτια και σε αυτά, που πιθανότατα, οφείλουν τις συγκεντρώσεις τους (τουλάχιστον ένα τμήμα των αναλυθέντων δειγμάτων) τόσο σε γεωλογικά αίτια, όσο και σε ανθρωπογενείς δραστηριότητες. Τα στοιχεία που ανήκουν στην πρώτη ομάδα είναι τα: Al, Ca, Fe, Mg, Si, Ce, Co, Ga, Ge, La, Li, Mn, Rb, Sb, Se, Sn, Sr, Ti, W, Y και Zr. Τα υπόλοιπα στοιχεία Cl, K, Na, P, S, Ag, As, B, Ba, Cd, Cr, Cu, Hg, Mo, Ni, Pb, Sn, Th, U, V και Zn, ανήκουν στην δεύτερη ομάδα. Το στοιχείο το οποίο φαίνεται να έχει το μεγαλύτερο εμπλουτισμό είναι το As. Ακολουθούν τα Pb και Zn και στη συνέχεια τα υπόλοιπα στοιχεία της δεύτερης ομάδας. Η χρήση διαγραμμάτων (και λογαριθμικών διαγραμμάτων) πιθανοτήτων έδειξε ότι μπορεί, σε αρκετά καλό βαθμό, να υπολογιστεί το φυσικό γεωχημικό υπόβαθρο επιφανειακών εδαφών, μιας περιοχής μελέτης. Για τα θαλάσσια ιζήματα, όπως και με τα επιφανειακά εδάφη, τα αναλυθέντα στοιχεία μπορούν να διαχωριστούν σε δύο ομάδες. Στην πρώτη ανήκουν τα Ca, Si και Sr, τα οποία οφείλουν τη συγκέντρωσή τους, κατά κύριο λόγο, σε γεωλογικά αίτια. Τα υπόλοιπα στοιχεία, οφείλουν τις αυξημένες συγκεντρώσεις τους σε ορισμένα δείγματα, κυρίως στις ανθρωπογενείς δραστηριότητες που πραγματοποιούνται στην περιοχή μελέτης. Αυτά τα στοιχεία μπορούν, επιπλέον, να διαχωριστούν σε τρεις ομάδες, ανάλογα με ποια δραστηριότητα μπορούν να συνδεθούν. Έτσι, τα στοιχεία P, Ag, As, Ba, Cd, Ce, Cu, Hg, Mo, Se, U, Y και Zn φαίνεται να οφείλουν τις αυξημένες συγκεντρώσεις τους στις δραστηριότητες της Β.Φ.Λ. Τα στοιχεία Κ, Β, Cs, και Rb παρουσιάζουν τις υψηλότερες συγκεντρώσεις μπροστά από την περιοχή όπου βρίσκονται η Kavala Oil, το ιχθυοτροφείο Ξιφίας και οι ανεξέλεγκτες χωματερές, ενώ τα στοιχεία Fe, Mg, Cs, Ga, Ge, La, Li, Mn, Pb, Rb, Sb, Ti και Zr φαίνεται να οφείλουν τις υψηλές συγκεντρώσεις τους σε συνδυασμό των ανθρωπογενών δραστηριοτήτων και ίσως, για μερικά στοιχεία (π.χ. Fe, Mn) και γεωλογικών παραγόντων. Τα δείγματα με τις υψηλότερες συγκεντρώσεις είναι τα SS100 και SS108 (μπροστά στη Β.Φ.Λ.), ενώ τα στοιχεία που εμφανίζουν το μεγαλύτερο πρόβλημα είναι τα Cd, As, Cu, Pb. Η όλη διαδικασία που ακολουθήθηκε στην παρούσα Διατριβή (διαλυτοποίηση με ΗΝΟ₃, ανάλυση με ICP-OES και ICP-MS, χρήση λογαριθμικών διαγραμμάτων πιθανοτήτων, χρήση Γεωγραφικών Συστημάτων Πληροφοριών) έδειξε ότι μπορεί να εφαρμοστεί, με αρκετά καλά αποτελέσματα, σε περιβαλλοντικές γεωχημικές μελέτες εδαφών και ιζημάτων

Ash Deposition in a Pulverized Coal-Fired Power Plant after High-Calcium Lignite Combustion

7 páginas, 5 figuras, 2 tablas.The fabric, mineralogy, and chemistry of high-calcium ash deposits from the Agios Dimitrios pulverized-lignite power plant in northern Greece have been investigated as a key to the ability to improve the performance of the power plant. All inner surfaces in the boiler are covered with a layer of particulate matter showing various degrees of agglomeration or with fouling deposits. Agglomerated fabric occurs in the lower and upper furnace sections, whereas sintered textures are mainly observed in the air heater sections. Particles in the size range of 10−50 μm with no sign of large agglomeration constitute the fly ash. Calcium mineral phases are dominant in deposits (anhydrite (CaSO4), calcite (CaCO3), portlandite (Ca(OH)2), and lime (CaO)); however, there are also significant amounts of silicon-containing minerals in bottom ash and fly ash (quartz (SiO2), gehlenite (Ca2Al2SiO7), and anorthite (CaAl2Si2O8)). Gas−solid reactions control deposition, without the participation of alkaline element compounds in the buildup of deposits. Technological modifications in the facility cannot improve the situation significantly, because of the fact that these effects are the consequence of the thermal decomposition of the high content of calcite (CaCO3) in the feed lignite, coming from the lignite seams and the intermediate sterile layers co-excavated with the lignite. Only through improvement of the quality of the lignite during mining can the power plant improve its operations.The authors would like to thank the assistance provided by the Aristotle University of Thessaloniki, the University of Barcelona (especially, the Scientific-Technical Survey), and the Institute of Earth Sciences, Jaume Almera-CSIC.Peer reviewe

A correlation study of major and trace elements in sediments of River Nestos, Northern Greece and comparison with other fluvial systems

8 páginas, 1 figura, 2 tablas.-- Trabajo presentado en: 9th International Scientific Conference of Modern Management of Mine Producing, Geology and Environmental Protection SGEM 2009, 14-19 june 2009, Albena, Bulgaria.Fourteen sediment samples from the banks of River Nestos, Northern Greece, were collected, extracted with HNO3 and analyzed for their content in 10 major and 32 trace elements. The analytical techniques used were ICP-OES and ICP-MS. The calculation of the Pearson Correlation Coefficient amongst the analyzed elements has revealed that among the majority of the elements exist positive correlations, which explains why most of them have a similar distribution along the river course. A comparison between the results acquired for the River Nestos and other fluvial systems, national and international, has shown the similarity of the geochemical identity of the River Nestos sediments with these systems.This work was partially carried out in the framework of PEGEFA 2005SGR-795 Research Consolidated Group, funded by AGAUR-DURSI, Generalitat de Catalunya.Peer reviewe

Slag and ash chemistry after high-calcium lignite combustion in a pulverized coal-fired power plant

6 páginas, 1 figura, 1 tabla.-- En: : Proceedings of the 9th International Conference on Environmental Science and Technology, Rhodes island, Greece (1,3-Sept.-05).More than 73% of the electrical power requirements of Greece are generated in lignite-fired power plants. Greece is the thirteenth largest coal and the fifth largest lignite producer in the world. The lack of domestic high-rank coals makes necessary to use low quality lignite for power generation in Greece. These lignites are characterized by a high water and ash content and a low calorific value. The low quality of such lignites generates important technical and environmental problems during combustion. Slagging and fouling are common inside the power units and affect with particular severity the power plants performance. Slagging deposits take place in the high temperature radiant sections of the boiler, and are usually associated with some degree of melting of the ash. Fouling deposits are produced in the lower temperature convective sections of the boiler, and are generally related to condensation on the low temperature tube surfaces. Problems in boilers associated with ash deposits include modification of the heat transfer in different sections of the furnace, physical distortion of metal pieces due to the weight of the deposit, clogging of burners, and corrosion and erosion of metal walls. Feed lignite always carries more than 20% of inorganic matter, and its mineralogy and chemistry are originally related to geological factors. Five representative samples were collected from the inner surfaces of Unit 1 of the Agios Dimitrios Power Plant, Northern Greece, reflecting the main types of ash deposits occurring in the combustion facility. The chemistry of these high-calcium ash deposits has been investigated. Moreover, a fly ash and a bottom ash samples were taken and analyzed in order to investigate their possible impact on the environment after land-filling. All samples were digested by using 2.5 ml HNO3, 5ml HF and 2.5 ml HClO4 (1:2:1). Sixty element concentrations were determined in all samples by inductively coupled plasma–mass spectrometry (ICP–MS) and inductively coupled plasma – optical emission spectrometry (ICP-OES). Calcium is the most abundant element in all samples due to the dominance of calcium phases. The chemical composition of the bottom ash, fly ash, slag and fouling deposits, is mainly influenced by the chemical composition of the feed lignite and the co-excavated sterile materials, which are marly limestones containing, on average, 93% of calcite.Peer reviewe

NEUTRALIZATION OF DYEING INDUSTRY WASTEWATER AND SLUDGE BY FIXATION OF POLLUTANTS IN VERY HIGH QUALITY HEU-TYPE ZEOLITIC TUFF

Treatment of dyeing industry wastewater of pH 7.5 with very high quality zeolitic tuff and coagulants, resulted in clear water of pH 7.2, free of odours and improved quality characteristics (colour, suspended particles, COD: Chemical Oxygen Demand, P2O5, NO3-, Cr) by 74 to 98%. The very high quality zeolitic tuff is 3 to 60% more effective than the coagulants, concerning COD, Cr and NO3-. The treatments produced sludge (using coagulants) and zeo-sludge (using very high quality zeolitic tuff and coagulants). The zeo-sludge is odourless and cohesive. The leaching by deionised water of sludge reached values up to 100% for the quality characteristics, while that of the zeo-sludge reached significantly lower values (only up to 18%). The chemical composition of the seepage water from the zeo-sludge proved the fixation of pollutants, such as NO3- and Cr by the very high quality zeolitic tuff

Arsenic Background Concentrations in Surface Soils of Kavala Area, Northern Greece

9 páginas, 6 figuras, 2 tablas.A total of 65 surface (0–20 cm) soil samples were collected in an effort to estimate the arsenic background values in Kavala area, Northern Greece. Arsenic was extracted by HNO3 from the <200 µm grain size fraction, and its concentrations were determined in all samples by inductively coupled plasma–mass spectrometry. Arsenic concentrations were log-transformed, and log-normal probability plots (Q–Q plots) were generated. The geochemical background was calculated as the values that lie between g/d and g × d (g, geometric mean; d, geometric standard deviation), which are 3.5 and 25.8 mg kg−1, respectively. The baseline value (g) was 9.5 mg kg−1. With the aid of GIS software, arsenic geochemical maps of the study area were created. The majority of the arsenic elevated concentrations were found in the proximity of the industrialized zone of Kavala.Georgios Papastergios, during this research, was under a scholarship from the Greek State Scholarships Foundation (IKY). This work was partially carried out in the framework of PEGEFA 2005SGR-00795 Research Consolidated Group, funded by AGAUR-DURSI, Generalitat de Catalunya.Peer reviewe

Arsenic distribution in sea sediments of Filippos B port, Kavala, Northern Greece

7 páginas.Nine sampling sites in the eastern Kavala coast, Northern Greece, were selected to collect sediments and analyze their content in arsenic. In past and recent years, arsenic has raised a lot of attention since it is considered to be a potentially toxic element. Arsenic concentrations ranged from 2.7 to 44.8 mg kg-1, and its average was 15.3 mg kg-1. Two samples with concentrations higher than 20 mg kg-1 were in front of the industrial facilities of the study area. However, a possible contribution from the sulphide mineralization present in the area may not be excluded. The sediments of Filippos B port have a similar range of arsenic concentrations compared to that of larger international ports. Comparison between the concentrations found in the present study and internationally accepted guidelines showed that the aforementioned samples exceeded the suggested optimum level, although no sampling location reached such a level where remediation actions are necessary.Peer reviewe

Natural and anthropogenic effects on the sediment geochemistry of Nestos river, Northern Greece

10 páginas.Fourteen sediment samples from the banks of river Nestos, Northern Greece, were collected, extracted with HNO3 and analyzed for their content in 10 major and 32 trace elements. The analytical methods used were ICP-OES and ICP-MS. The results indicate that the sediments in the northern Greek part of the river have the highest elemental concentrations partly because of human activities, but mainly due to natural processes. The two dams that have been constructed in the middle course play a buffering role on the elemental content, for all the elements analyzed, of the river sediments, decreasing downstream concentrations and sediment load. An increase of concentrations is newly observed in the low course and delta because of the mobilization of fine sediments by natural processes and agricultural practices. The comparison of the river sediment contents with contaminated land guidelines has not revealed any potentially dangerous concentrations for the elements analyzed.Peer reviewe