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Methodologies to assess the fate of polar organic compounds in aquatic environmentsMagnér, Jörgen January 2010 (has links)
Polar organic compounds (POCs) are chemicals with polar functional groups in their structure. The functional groups make the compounds hydrophilic and less prone to partition with biota. However, the knowledge of their fate is limited due to difficulties associated with their measurements. Although, the persistence of POCs in the environment is generally low, they are considered to be semi-persistent compounds due to their continuous introduction to the environment via wastewater. Studies have shown that complex mixtures of POCs of different classes may have synergistic toxic effects on biota at environmental concentration levels. Therefore, it is important to develop analytical methods in order to establish the occurrence and fate of POCs in aquatic environments. In Study I, a positive correlation between the sorption of a novel poly(ethylene-co-vinyl acetate-co-carbon monoxide) (PEVAC) material and the theoretical logarithmic dissociation partition coefficient (Log D) for seven POCs was observed. The PEVAC material showed an enhanced sorption of the POCs compared to the silicone material. Study II, demonstrated that the PEVAC sampler assess the freely dissolved concentration of POCs in aquatic environments. The results showed that the PEVAC polymer is an attractive alternative to silicone for mimicing the biological uptake of POCs in aquatic environments. Additionally, Study II showed that total extraction is appropriate for determination of the freely dissolved concentration of uncharged POCs with Log KOW < 2.67 in natural water. In study III, a novel bag-solid phase extraction (bag-SPE) technique was compared to a conventional SPE-technique. Despite that the extraction efficiencies for POCs in wastewater were lower using the bag-SPE method, the two methods showed similar detection limits due to the lower ion-suppression experienced with the bag-SPE. In study IV the bag-SPE method was further developed with the aim of lowering the detection limits for POCs. Detection limits (LOD) below 13 ng/L showed that the bag-SPE method was suitable for determination of POCs in surface sea water. / This research was financially supported by European Union (European Commission, FP6 Contract No. 003956) “Novel Methods for Integrated Risk Assessment of Cumulative Stressors in the Environment” (NoMiracle) and by the Swedish research council Formas.
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Eliminación del Biofouling en intercambiadores de calor-condensadores que minimicen el impacto ambiental en el medio marinoRío Calonge, Belén 28 September 1999 (has links)
La presente tesis doctoral tiene por objeto tratar de eliminar el fenómeno no deseable de formación de biofouling en diferentes superficies tubulares de intercambiadores de calor, mediante tratamientos físicos y químicos, intentando minimizar el impacto ambiental creado en los efluentes de las instalaciones industriales.El equipo experimental está compuesto por una planta piloto de intercambiadores de calor condensadores dotada de ocho tubos que funcionan como sistemas independientes, donde se controlan los parámetros de presión, temperatura y caudal, que define indirectamente el biofouling depositado en el interior de dichos tubos a través de los valores de resistencia friccional al flujo y resistencia a la transferencia de calor.También ha sido diseñado y construido otra planta piloto o monitor "MCMDID" (monitor combinado de medición directa e indirecta del biofouling) donde se mide en continuo el espesor del biofouling adherido a la superficie de un tubo del mismo material que los ensayados en la planta descrita anteriormente.
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Περιβαλλοντική υδρογεωλογική έρευνα του προσχωματικού υδροφόρου της περιοχής Κιάτου - Κορίνθου. Κατασκευή μοντέλου προσωμοίωσης της υπόγειας ροήςΤάντος, Βασίλειος 03 December 2008 (has links)
Η περιοχή μελέτης εκτείνεται στο βόρειο και παραλιακό τμήμα του νομού Κορινθίας μεταξύ των πόλεων Κιάτου και Κορίνθου και καταλαμβάνει έκταση 65km2. Η νέα εθνική οδός Κορίνθου – Πατρών αποτελεί το νότιο όριο της περιοχής ενώ προς βορρά περιορίζεται από τον Κορινθιακό κόλπο. Το τοπογραφικό ανάγλυφο είναι ήπιο με το υψόμετρο να κυμαίνεται από 0 – 50 μέτρα. Ο ποταμός Ασσωπός και οι χείμαρροι Ραχιάνης και Ζαπάντης δομούν το υδρογραφικό δίκτυο της περιοχής.
Το γεωλογικό υπόβαθρο της περιοχής αποτελείται από ανθρακικά ιζήματα των ζωνών Τρίπολης και Πίνδου, των οποίων υπέρκεινται μετα-ορογεντικά ιζήματα Πλειο-πλειστοκαινικής ηλικίας. Ο υδροφόρος ορίζοντας που μελετήθηκε αναπτύσσεται σε αλλουβιακά ιζήματα, κυρίως άμμους, κροκάλες, λατύπες, και λεπτομερή αργιλοαμμώδη και πηλοαμμώδη ιζήματα που εμφανίζουν υψηλό βαθμό ετερογένειας. Το πάχος του υδροφόρου κυμαίνεται από λίγα μέτρα έως 60 m και χαρακτηρίζεται ως ελεύθερος.
Η ρηξιγενής ζώνη που εμφανίζεται κατά μήκος της Ν.Ε.Ο. Κορίνθου – Πατρών αποτελεί υδρογεωλογικό όριο προς νότο για τον υπό μελέτη υδροφόρο. Η εμφάνιση μαργών στην περιοχή του Κιάτου είναι το δυτικό υδρογεωλογικό όριο, ενώ ανατολικά περιορίζεται από την επέκταση των Τυρρήνιων αναβαθμίδων στη θάλασσα.
Η κύρια τροφοδοσία του υδροφόρου προέρχεται από τη διήθηση των επιφανειακών υδάτων του ποταμού Ασωπού και των παρακείμενων χειμάρρων, ενώ κατά δεύτερο λόγω από την απευθείας κατείσδυση των ατμοσφαιρικών κατακρημνισμάτων.
Για την προσομοίωση της υπόγειας ροής του αλλουβιακού υδροφόρου έγινε χρήση του κώδικα MODFLOW της USGS. Από την εφαρμογή του μοντέλου εξήχθησαν ικανοποιητικά αποτελέσματα που έδωσαν τη δυνατότητα υπολογισμού ενός αξιόπιστου ισοζυγίου, το οποίο μπορεί να αποτελέσει ένα εργαλείο στην εφαρμογή ενός σχεδίου ορθολογικής διαχείρισης των υδατικών πόρων της Κορινθίας.
Για την υδροχημική έρευνα χρησιμοποιήθηκε πυκνό δίκτυο δειγματοληψίας νερού σε 35 υδροσημεία της περιοχής μελέτης. Ο υδροφόρος έχει επηρεαστεί από φαινόμενα υφαλμύρινσης και ανταλλαγής ιόντων κυρίως στις βόρειες παράκτιες ζώνες. Οι συγκεντρώσεις των NO3-, NH4+ και των SO4-2 ιόντων παρουσιάζονται υψηλότερες από τα ανώτατα επιτρεπόμενα όρια ποσιμότητας. Η εφαρμογή της παραγοντικής ανάλυσης ανέδειξε τις παραπάνω υδροχημικές διεργασίες. / The study area forms the northern coastal part of Corinth’s prefecture, between the towns of Kiato and Corinth and has an area extend of 65 km2. To the south it is bounded by Athens - Patras National road, whilst to the north it is bounded by Corinthian Gulf. The topographic relief is quite gentle and varies from 0 to 50 m. A considerable hydrographic network develops across the studied region and is represented mainly by the river Asopos and the less important torrents Rachianis and Zapantis. The region can be characterized as an agro tourism center. The land is used mainly for the cultivation and of citrus fruits, olives, apricots and vineyards. Regional environment is subject to numerous pressures most important of which are intensified uses of land and water resources. Water demands have considerably increased over the last 15 years and mainly are covered by groundwater abstract from the alluvial aquifer system.
The geological bedrock of the study area consists of the carbonate sediments of Tripolis and Pindos isopics zones and a transitional zone between Pindos and Pelagonial Zone.
The plain north of the national zone is covered by post orogenetic sediments of Pliocene to Holocene age which unconformably overlay the bedrock formations. The studied aquifer is formed of recent unconsolidated material consisting of sands, pebbles, breccias and fine clay to silty sand deposits, characterized by high degree of heterogeneity and anisotropy. The thickness of the aquifer varies from a few meters to 40 m. From a hydrogeological point of view the system consists of an unconfined phreatic aquifer. A fault zone along the national highway delineates the southern edge of aquifer system, which is bounded by the Gulf of Corinth to the north. To the east, the system is bounded by the Tyrrhenian deposits extended to the sea. The marl series which, as an entity, is considered an aquitard, slopes to the north and forms the bedrock of the studied coastal alluvial aquifer system.
The basic recharge of the phreatic aquifer is from the fluviotorrential deposits, especially those of the Asopos River and also from the Tyrrhenian deposits across the southern edge of the basin. In addition to that the aquifer recharged from direct infiltration of precipitation and river bed indirect infiltration.
The simulation of ground water flow of the alluvial aquifer is based on the MODFLOW model of the USGS. The application of the mathematical model had very satisfactory results which is a reliable hydrogeological balance. Estimation of hydraulic conductivity distribution was optimized by using trial and error inverse method.
The ground water hydrochemical study was carried out, by an extensive network of 35 samples. The use of inorganic fertilizers in cultivations has a great pollution effect in ground water. The coastal aquifer has been affected, by sea water intrusion and as a result catio-exchange phenomena took plase along the coastline mainly at Lechaio area. The concentration of NO3- , NH4+, and SO4- ions are higher than the maximum allowed drinking limits. The application of R-mode factor analysis helped to delineate the major hydrochemical process of the area.
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A técnica de Blue rayon in situ associada ao teste Salmonella/microssoma como estratégia para o monitoramento de águas estuarinas quanto à presença de compostos policíclicos genotóxicos / The Blue rayon technique in situ associated with the Salmonella / microsome test as a strategy for monitoring estuarine waters for the presence of genotoxic polycyclic compoundsFábio Kummrow 07 March 2006 (has links)
O estuário de Santos abriga o maior porto da América Latina e um dos maiores complexos industriais do Brasil. Na década de 1970 foi considerado um dos maiores exemplos de degradação ambiental em ambientes costeiros, e apesar da melhora na qualidade ambiental observada nos últimos anos algumas áreas deste estuário apresentam sedimentos ainda altamente contaminados com compostos tóxicos e genotóxicos, especialmente os Hidrocarbonetos Policíclicos Aromáticos (HPA). Operações de dragagem para manutenção das atividades portuárias são necessárias e consequentemente durante este processo pode ocorrer a ressuspensão de contaminantes presentes nesses sedimentos, tornando-os disponíveis novamente na coluna d\'água. Desta forma é interessante ter uma estratégia eficiente e aplicável no monitoramento da qualidade dessas águas. O Blue rayon (BR) é um adsorvente seletivo para compostos policíclicos com três ou mais anéis fundidos em sua molécula e tem sido utilizado com sucesso no monitoramento de HPA e atividade mutagênica em ambientes aquáticos. Este trabalho teve como objetivo padronizar o uso da técnica de Blue rayon in situ ancorado, onde as fibras são fixas a uma distância padronizada dos sedimentos, associada ao teste de Salmonella/microssoma em microssuspensão a ser aplicada no monitoramento das águas desse estuário. Foram selecionados três pontos de amostragem com diferentes características e sedimentos com variados níveis de contaminação. As duas campanhas iniciais foram realizadas com o objetivo de avaliar a eficiência do BR e de escolher a linhagem de Salmonella mais sensível aos compostos mutagênicos possivelmente presentes nos extratos obtidos bem como verificar a presença de HPA. As cinco campanhas posteriores foram realizadas para verificar o comportamento e a eficiência da estratégia previamente definida no monitoramento das águas desse estuário utilizando experimentos de dose resposta. Os resultados obtidos nas duas primeiras campanhas mostraram que as águas do ponto 1, que contém os sedimentos mais contaminados e recebe os efluentes da COSIPA, apresentam maior contaminação por HPA e atividade genotóxica mais elevada que o ponto 2. Também foi possível determinar que a linhagem de Salmonella YG1041 foi a mais sensível para detectar atividade mutagênica tanto no ponto 1 quanto no ponto 2. Nas cinco campanhas subsequentes as maiores potências mutagênicas foram também observadas no ponto 1 com valores máximos de 5.100 e 36.000 revertentes/g de BR para a linhagem YG1041 na ausência e na presença de ativação metabólica (S9) respectivamente. Nos pontos 2 e 3 as potências observadas foram similares entre si, com valores em torno de 1.000 revertentes/g de BR. Com base nos resultados obtidos nas duas etapas deste trabalho pode-se concluir que a o Blue rayon utilizado in situ a uma distância padronizada dos sedimento associado ao teste de Salmonella/microssoma em microssuspensão com a linhagem YG1041 na presença e na ausência de ativação metabólica (S9) é uma ferramenta que pode ser aplicada no monitoramento da qualidade do estuário de Santos. / Santos estuary is the major Latin American harbor and one of the largest industrial complex of Brazil. In the 1970s, it was considered one of the major examples of coastal degradation. Due to enforcement actions the quality of the environment has improved in the last years in relation to the chemical parameters and toxicity but unfortunately the sediment is still contaminated with toxic and genotoxic compounds especially Polycyclic Aromatic Hydrocarbons (PAHs). For the maintenance of the port activities sediment dredging is needed and during this process contaminants resuspension can occur, leading to the contamination of the water column. Therefore it is interesting to have an efficient strategy that can be used for the water quality monitoring of this area. The Blue rayon is a selective adsorbent to polycyclic compounds containing three or more fused rings and has been successfully used in the monitoring of PAHs and mutagenic activity in aquatic environments. The objective of this work was to evaluate a modified blue rayon hanging technique, denominated in this work \"Blue rayon anchored technique\", where the fibers are placed at a fixed distance from the sediment, associated with the Salmonella/microsome microsuspension assay in order to monitor the water quality of Santos estuary. Three sites with different sources and sediment contamination levels were selected in this study. Two initial samplings were performed in order to evaluate the efficiency of the BR modified technique and find the most sensitive strain of Salmonella typhimurium to the mutagens possibly present in the those waters as well as verify the presence of PAHs. Five subsequent samplings were performed to verify the performance and efficiency of the defined strategy in the estuary water quality monitoring using dose response experiments. In the two initial samplings, the water from the site containing the most contaminated sediment and under influence of COSIPA (site 1) presented higher mutagenic activity and higher levels of PAHs. It was also possible to verify the highest sensitivity of the YG1041 strain in the detection of the mutagenic activity in both sites analyzed. In the subsequent five samplings, higher mutagenic potencies were again observed for site 1, reaching 5,100 and 36,000 revertants per gram of BR for the YG1 041 strain in the absence and presence of S9 respectively. Sites 2 and: presented similar potencies, around 1000 revertants per gram of BR. Based on the obtained results we can conclude that the Blue rayon anchored technique associated with the Salmonella/microsome microsuspension assay with the YG1041 strain in the presence and absence of S9 is an suitable tool to monito Santos estuarine waters.
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Περιβαλλοντική έρευνα των υδροφόρων οριζόντων του ΒΔ Λασιθίου με τη χρήση σπάνιων γαιών / Environmetal study of karstic aquifers in region NW Lasithi using rare earth elementsΠυτικάκης, Εμμανουήλ 28 June 2007 (has links)
Στην περιοχή του ΒΔ Λασιθίου απαντώνται οι γεωλογικοί σχηματισμοί των πλακώδων ασβεστόλιθων και των ασβεστόλιθων της ζώνης Τρίπολης. οι σχηματισμοί αυτοί είναι έντονα καρστικοποιημένοι και αποτελούν τους κύριους υδροφόρους της περιοχής έρευνας. Μεταξύ των δύο υδροφόρων, στις περιοχές Νεάπολης και Ποτάμων παρεμβάλλονται τα αδιαπέρατα στρώματα των Φυλλιτών-Χαλαζιτών. Ο υδροφόρος που αναπτύσσεται στους ανθρακικούς σχηματισμούς της ζώνης Τρίπολης κατηγοριοποιείται σε τρεις ζώνες σύμφωνα με τον υδροχημικό χαρακτήρα του υπόγειου νερού. η πρώτη ζώνη αποτελείται από τις περιοχές τροφοδοσίας του υδροφόρου (Δράσι, Άγιος Κωνσταντίνος και Ποτάμοι) με εξαίρετη ποιότητα νερού, η δεύτερη ζώνη συνιστάται από τις περιοχές των Λακωνίων και Κριτσάς, όπου το νερό του υδροφόρου έχει επηρεαστεί από τη διείσδυση του θαλασσινού νερού. Τέλος, η τρίτη ζώνη αποτελείται από τις παράκτιες περιοχές του Αγίου Νικολάου και Αλμυρού με έντονη επιρροή από την διαδικασία της υφαλμύρινσης Ο υδροφόρος που αναπτύσσεται στους Πλακώδεις ασβεστόλιθους είναι ανοικτός στην θάλασσα και επηρεάζεται στο σύνολο του από την διείσδυση του θαλασσινού νερού. Με τη χρήση των κανονικοποιημένων διαγραμμάτων των σπάνιων γαιών, τόσο σε δείγματα πετρωμάτων όσο και σε δείγματα νερού προέκυψε ότι οι δύο καρστικοί υδροφόροι επικοινωνούν υδραυλικά στην περιοχή του Δάμακα Β-ΒΔ του Αγίου Νικολάου. / The region of NW Lasithi is dominated by plattenkalk and Tripoli’s zone limestones. These geological formations are characterized by karst and host the main aquifers of study area. Impermeable layers of phyllite-quartzite formation occur between these limestone formations, in the areas of Neapolis and Potami. The aquifer hosted by the carbonate formations of Tripoli’s zone is divided in three zones based on the hydrochemical characteristics of the underground water. The first zone includes the areas Drasi, Agios Konstantinos and Potami that are the sources of the aquifer, with excellent water quality. The second zone consists of the areas Lakonia and Kritsa, in which the underground water have been infiltrated by sea water. Finally the third consists of the coastal zones of Agios Nikolaos and Almyros, which have been affected by the process of brackish water. The aquifer hosted by the plattenkalk limestones is open to the sea and is affected by the intrusion of sea water. It can be shown, using normalized rare earth element diagrams of analyses of both rocks and underground waters, that the two karstified aquifers communicate hydraulically in the area of Damakas, N-NW of city Agios Nikolaos.
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Diatoms from the late Holocene of the western Chukchi Sea, Arctic Ocean: environmental signals and palaeoceanography / Diatoméer från sen holocen i västra Tjukjerhavet, Arktiska oceanen: miljösignaler och paleoceanografiBrowaldh, Erik January 2022 (has links)
The sediment Core SWERUS-L2-2-PC1 (2PC) retrieved from the Chukchi Sea, Arctic Ocean sits in an oceanographically dynamic location at the Arctic-Pacific Ocean gateway. The 8.3 m-long core was retrieved in Herald Canyon at the marginal ice zone at 57 m depth. Core 2PC is well-positioned to record variability in inflow of Bering Sea Water (BSW) and Pacific Water (PW) in Herald Canyon. With the 2PC high sedimentation rate (200 cm/kyr), two independent age models (radiocarbon and palaeomagnetism) based on tephra age markers, and a richness in well-preserved siliceous sediment, validate 2PC as an outstanding sequence for applying diatom assemblage analysis as a proxy for ocean-climate change back to 4250 years BP, including the past few hundred years where global warming and sea ice decline is recorded by instrumental records. These characteristics make Core-2PC a useful record for investigating the role of PW on sea ice variability in the Chukchi Sea, both in the past and predicting the future. To investigate the impact of PW on ocean and sea ice conditions in the Chukchi Sea, diatom assemblage analysis was performed on 49 samples through the Late Holocene. The over-arching goal was to test the hypothesis, suggested by existing research on 2PC using benthic foraminifera Mg/Ca palaeothermometry, that the strength of PW inflow into the Chukchi Sea via Herald Canyon has varied on a time scales of ~500-1000 years in the past 4000 years. PW is slightly warmer than resident Arctic surface waters and is known to be an important control on Arctic sea-ice. The diatom assemblage approach assumes that there are recognizable differences between end-member diatom assemblages that are characteristic of PW versus Arctic Ocean type environments associated with extensive sea-ice conditions. The mapping of species in the Herald Canyon was used to test the idea of variability of sea-ice extent and the role of the Pacific Ocean forcings into the western Chukchi Sea. The results reveal diverse diatom assemblages throughout the past 4000 years in Herald Canyon, showing this core to be very useful for diatom palaeoclimate reconstructions. A total of 126 species with abundance >1% are recognized. Several generalist species typically dominate assemblages especially Chaetoceros, ice-algae, marine-neritic and near ice or cold-water planktic centric diatoms. Distinct changes in stratigraphy are illustrated by changes in identified diatom assemblage zones. The 2PC diatom assemblages were contrasted with records from Chukchi-, Laptev-, East Siberian- and Bering Sea and North Pacific Ocean. At 2PC, sympagic (sea-ice related), planktic and neritic species abundance varies on time scales of ~500-1000 years. Importantly, there is a clear similarity between the timing of diatom assemblage changes and the 2PC benthic foraminifera Mg/Ca bottom water temperature (BWT) reconstruction. In particular, abundance changes in the warm water species Thalassionema nitzschioides, Shionodiscus oestrupii and Thalassionema simonsenii, tychoplanktic Paralia sulcata, Ice algae- and sympagic assemblages and cold-water indicators correspond best to BWT fluctuations shown by the Mg/Ca reconstruction. These oscillations are suggestive of changes in warmer PW inflow. Other aspects of the diatom data appear to correlate with colder and warmer climate events and suggest that changes in PW inflow amplified the effects of these events in the Chukchi Sea region through the Late Holocene in the Northern Hemisphere. It can thus, be concluded that diatoms from 2PC, support the palaeoceanographic reconstruction suggested by the benthic foraminifera Mg/Ca palaeothermometry and that variations in PW inflow through Herald Canyon is an important driver of sea ice variability on thousand-year time scales.
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Distribuční soustava Kypru - realizovatelnost obnovitelných zdrojů a přenos energie / Distribution system of Cyprus - feasibility of renewable energy sources and transfer of energyŠimonová, Lucie January 2011 (has links)
Until a few decades ago few people could imagine that the photovoltaic, solar thermal and other power based on renewable resources, will become a reality. Today people from all over the world on the contrary try at full blast derive benefit from of all possible available source. Using sunlight as a source of energy is first enforced only for small devices such as calculators for charging the battery, but now we are able to produced energy from the sun to supply people around the world. Of course it is not possible supply consumer sector plus firm only from performances renewable power supply. Therefore endeavour is derive benefit from classical energy production at the same time with others power supply. The basic components of photovoltaic and solar thermal power are panels. The panels are made of different materials in different shapes and sizes. During production, the resulting effect looks in addition to costs associated with production. For photovoltaic and solar thermal power plant requires sufficient sunlight. The sunshine has biggest intensity on south of ours planets. Therefore endeavour is build lump these power station just in stand with bigger intensity sunshine. One of them is just Cyprus, too.
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