Cette thèse porte sur le comportement d’un composé prioritaire au titre de la Directive Cadre sur l’Eau au niveau européen : le tributylétain (TBT) et ses métabolites (dibutylétain (DBT) et monobutylétain (MBT)). On s’intéresse plus particulièrement aux eaux usées domestiques lors de leur transit dans deux stations d’épuration par lagunage naturel (STEP), traitement adapté aux effluents provenant des zones faiblement urbanisées. Ce travail de thèse vient combler le manque de résultats scientifiques sur (1) le niveau des concentrations en butylétains dans les effluents domestiques des zones peu urbanisées en entrée des stations par lagunage et en sortie après traitement ; (2) l’efficacité du traitement par lagunage à éliminer les butylétains ; (3)l’identification des processus qui contrôlent le devenir de ces éléments au cours du traitement.Les butylétains sont mesurés dans les matrices particulaires, dissoutes et dans les boues, par couplage GC-ICP-MS, dans toutes les étapes du traitement par lagunage de deux communes rurales du département de l’Hérault (34,France) : Gigean (6000 eq-hab.) et Montbazin (4500 eq-hab.). On montre que les trois espèces butylées sont systématiquement présentes dans tous les échantillons prélevés sur les deux STEP. Les butylétains arrivent principalement sous forme particulaire dans les eaux brutes en entrée des stations. Au cours du traitement, les processus de sorption sur les particules en suspension et la décantation de ces dernières au fond de chaque bassin sont les principaux facteurs permettant l’élimination des butylétains. Les premiers bassins anaérobies, de grande profondeur et de long temps de séjour, permettent l’élimination de plus de 60% à Gigean (93% à Montbazin) des butylétains. Les boues de fond de chaque bassin montrent des concentrations élevées en butylétains. La remise en suspension des butylétains est notée dans les derniers bassins de finition, peu profonds, ce qui peut être due à la re-stratification thermique. En sortie de station, malgré les abattements importants, des concentrations non négligeables en butylétains (12 à 228 et 1.8 à 15 ng(Sn).L-1 respectivement pour Montbazin et Gigean) sont rejetées dans le milieu récepteur. Des expériences de sorption basées sur la mise en contact de butylétains avec des boues de fond de bassin diluées ont été effectuées selon plusieurs approches expérimentales. On a ainsi montré que (1) la distribution des espèces MBT, DBT, TBT, entre les phases solide et liquide, est variable d’un test à l’autre selon les conditions opératoires ; (2) l’affinité entre les butylétains et la boue est importante, quelle que soit sa provenance. 98% des butylétains se retrouvent dans la phase solide, du fait de leur hydrophobicité. Le coefficient de distribution Kd entre le TBT et les boues est plus élevé que celui obtenu pour d’autres type de phases solides (75000 L.kg- 1) ; (3) le processus de sorption est rapide. De plus des processus de sorption, désorption et déalkylation du TBT, expliquant les variations des concentrations en MBT et DBT dans la phase solide ont été identifiés. La désorption du TBT est rapide. Il se dégrade dans la phase liquide en DBT dont une partie se transforme en MBT. La sorption du MBT sur les boues a été systématiquement mesurée. Le phénomène de sorption n’est donc pas complètement réversible au cours du temps. Ces résultats contribuent à expliquer les dysfonctionnements observés dans les stations de traitement par lagunage, par exemple lors d’apports directs d’eau de pluie.Cette thèse démontre la présence systématique des butylétains dans les stations d’épuration par lagunage naturel. Les données acquises in-situ couplées à des essais en laboratoire permettent de comprendre le comportement de ces composés lors de ce traitement : la fraction solide joue un rôle clé dans les processus de sorption-désorption-(bio)dégradation des butylétains. / This thesis deals with the behavior of a priority compound on the basis of the framework Directive on water at European level: tributyltin (TBT) ) and its metabolites (dibutyltin (DBT) and monobutyltin (MBT)). The study is focused on two waste stabilization pond treatment plants (WSP), which is an appropriate treatment to domestic effluents from sparsely urbanized areas.This thesis comes to fill the lack of scientific results on (1) the level of butyltin concentrations in domestic effluents from sparsely urbanized areas, in the input of the WSP and the output after treatment; (2) the efficiency of butyltins elimination by the WSP treatment; (3) the identification of the processes that control the fate of these elements during the treatment.Butyltins are measured in particulate and dissolved matrices and in sludge, by GC-ICP-MS, in all stages of the treatment by lagooning of two villages of the Department of Hérault (34, France): Gigean (6000 p.e.) and Montbazin (4500 p.e.).It is shown that the three butyltin species are consistently present in all samples taken from the two WSP. Butyltins arrive primarily in particulate form in the raw water. During treatment, the processes of sorption onto particulate matter and the settling of the latter at the bottom of each basin are the main factors for the elimination of butyltins. The first anaerobic ponds, characterized by deep depth and long residence times, allow the elimination of more than 60% Gigean (93% at Montbazin) of butyltins. Bottom sludge of each basin show high butyltins concentrations. The resuspension of butyltins is noted in the last maturation ponds, characterized by shallow depth, which may be due to re-thermal stratification. At the outlet, despite significant butyltin removal, concentrations in butyltins remain high (12 to 228 and 1.8 to 15 ng (Sn). L-1, respectively for Montbazin and Gigean).Laboratory batch experiments were conducted to study sorption processes following several experimental protocols. It was thus shown that: (1) the distribution of the butyltin species between solid and liquid phases is different from one test to another according to the operating conditions; (2) the affinity between butyltins and bottom sludge is important, regardless of its provenance. 98% of the butyltins are found in the solid phase, due to their hydrophobicity. The TBT sludge-water partition coefficient is higher than that obtained for other type of solid phases (75000 L.kg-1); (3) the process of sorption is fast.Moreover processes of sorption, desorption and dealkylation of TBT, explaining changes in concentrations of MBT and DBT in the solid phase were identified. Desorption of TBT is fast. It degrades in the liquid phase in DBT which part turns into MBT. The sorption of MBT on sludge has been systematically measured. Therefore, the sorption phenomenon is not completely reversible over time. These results help to explain the dysfunctions observed in WSP, for example after direct inputs of rainwater.This thesis shows the systematic presence of butyltin in waste stabilization pond treatment plants. In-situ data coupled with laboratory tests allow to understand the behaviour of these compounds during this treatment: the solid fraction plays a key role in the processes of sorption-desorption-(bio) degradation of butyltins.

Submitted by Mariana Dornelles Vargas (marianadv) on 2015-04-10T19:29:16Z No. of bitstreams: 1 influencia_variabilidade.pdf: 2460487 bytes, checksum: 14d53357bd40cb3e9c4c2a4ec2ac0ec8 (MD5) / Made available in DSpace on 2015-04-10T19:29:16Z (GMT). No. of bitstreams: 1 influencia_variabilidade.pdf: 2460487 bytes, checksum: 14d53357bd40cb3e9c4c2a4ec2ac0ec8 (MD5) Previous issue date: 2014-11-27 / Nenhuma / As estações de tratamento de água (ETA) são consideradas fontes de poluição, por gerarem resíduos sólidos como subproduto do próprio processo de tratamento. Por falta de adoção das políticas específicas de gerenciamento pelas ETAS, o lodo de estação de tratamento de água (LETA) tem sido disposto de forma ambientalmente inadequada, em cursos d'água. Uma alternativa viável seria a utilização deste LETA na fabricação de cerâmica vermelha destinada a construção civil, sendo assim, este trabalho tem por objetivo avaliar a influência da composição química do LETA, alterado pela qualidade da água a ser tratada, nas propriedades de cerâmica vermelha produzidas com este resíduo. Para atingir a finalidade proposta utilizaram-se 3 amostras de LETA, coletadas em Agosto de 2013, Dezembro de 2013 e Março de 2014 e uma amostra de argila, que foi amostrada em uma Olaria localizada em Porto Alegre – RS. A metodologia dividiu-se em coleta e caracterização das matérias primas, produção das 4 cerâmicas diferentes e caracterização das propriedades químicas, físicas e mecânicas das cerâmicas. O LETA foi prensado com adição de Cal para a retirada de excesso de água em um filtro prensa e caracterizado por meio dos ensaios de sólidos totais, fixos e voláteis, FRX, DRX, solubilização e lixiviação. Na argila, o LETA prensado foi empregado em adição de 5% em relação à massa total e então homogeneizado para a realização da extrusão dos corpos de prova. Os corpos de prova foram sinterizados em forno mufla nas temperaturas de 800°C, 950°C e 1050°C. As cerâmicas foram caracterizadas quanto à composição química e mineralógica, perda ao fogo e caracterização ambiental. Analisou-se a retração linear, a absorção de água e resistência à flexão dos corpos de prova. A composição química do LETA apresentou influência significativa nas propriedades estudadas das cerâmicas sinterizadas à 950ᵒC e 1050ᵒC, sendo que a propriedade mais afetada foi a absorção de água inicial sinterizada em 950ᵒC, obtendo-se um acréscimo de 61% nos corpos de prova B e 12% nos corpos de prova CPD em relação as cerâmicas de referência. Na temperatura de 1050ºC as cerâmicas apresentaram problema de baixa absorção de água. Nas cerâmicas sinterizadas à 800ºC as propriedades físicas e mecânicas não foram alteradas significativamente pela adição de lodo, mostrando-se viável a adição de LETA na cerâmica sinterizada nesta temperatura. / The water treatment plants (WTP) are considered point sources of pollution, for generating solid waste as a byproduct of the treatment process itself. For lack of adoption of specific management policies by WTP, the WTS has been disposed of improperly in environmentally watercourses. A viable alternative would be to use this WTS in the manufacture of red ceramic intended for construction, so this work aims to evaluate the influence of the chemical composition of the WTS, as amended by the water quality be treated in the properties of red pottery produced with this residue. To reach the proposed aim we used three samples of WTS, collected in August 2013, December 2013 and March 2014 and a sample of clay, which was sampled in a Pottery located in Porto Alegre - RS. The methodology divided into collecting and characterization of raw materials, production of 4 ceramics and characterization of different chemical, physical and mechanical properties of ceramics. The WTS was pressed with addition of lime for the removal of excess water and characterized by means of tests solids, fixed and volatile, XRF, XRD, solubilization and leaching. In clay, the WTS go been employed in addition of 5% relative to the total mass, and then homogenized for carrying out the extrusion of test specimens. The specimens were sintered in a muffle furnace at temperatures of 800°C, 950°C and 1050°C. The ceramics were characterized for chemical and mineralogical composition, loss on ignition and environmental characterization. We analyzed the linear shrinkage, water absorption and flexural strength of the ceramics. The chemical composition of WTS significantly affecting the properties of the ceramic sintered on 950ᵒC and 1050ᵒC, being the most affected absorption property was on 950ᵒC the initial water absorption, yielding an increase of 61% in the specimens CPB and 12 % CPD in the samples in relation to the reference ceramic. On the temperature 1050ºC, presented low water absorption. In the ceramics sintered at 800 ° C the physical and mechanical properties were not change significantly by the addition of sludge, being feasible the addition of WTS in this temperature.

För att kunna möta framtidens striktare reningskrav för avloppsvatten och en ökad belastning på grund av befolkningstillväxt bygger Stockholm Vatten och Avfall (SVOA) om Henriksdals reningsverk inom projektet Stockholms Framtida Avloppsvattenrening (SFA). En av de större förändringarna i det framtida Henriksdals reningsverk är införandet av MBR-teknik, där slam och vatten avskiljs genom membranfiltrering. Separationen medför förändrade egenskaper hos slammet då en större andel av partiklarna kan avskiljas från utgående vatten jämfört med avskiljning från konventionella sedimentationsbassänger. På Hammarby Sjöstadsverk drivs en pilotanläggning där MBR-teknik undersöks inför implementering i framtida Henriksdals reningsverk. Denna studie har undersökt skillnader i mängd partiklar, organiskt innehåll, filtrerbarhet, sedimenteringsegenskaper och förtjockningskapacitet hos överskottslam från MBR-linjen på Hammarby Sjöstadsverk (ÖS-MBR) och Henriksdals reningsverk (ÖS-CAS). Detta för att ge underlag till optimering av framtida slambehandling på Henriksdals reningsverk. Därutöver har massbalans för förtjockningsförsöken beräknats. Resultatet av studien visar att egenskaperna hos ÖS-MBR och ÖS-CAS skiljer sig tydligt för torrsubstans (TS), totalt suspenderade partiklar (TSS) och filtrerbarhet (TTF). Ingen skillnad i slamvolymindex (SVI) kunde verifieras i studien. Efter förtjockning av slammen i en trumsil, med olika polymertillsats, uppvisade ÖS-MBR högre TSS i rejektvattnet än ÖS-CAS. Denna skillnad indikerar att partiklar i ÖS-MBR har mindre benägenhet att binda till polymeren som användes, än partiklar i ÖS-CAS. Det är därför av betydelse att pröva ut rätt typ av polymer vid förtjockning av ÖS-MBR, för att nå målet på en TSS under 1000 mg/L i rejektvattnet. Därtill uppvisade ÖS-MBR högre TS i det förtjockade slammet än ÖS-CAS. Detta skulle kunna indikera att ÖS-MBR är lättare att förtjocka än ÖSCAS, men det kunde dock inte bekräftas av massbalanserna. Slutligen kunde denna studie inte samstämmigt visa på en skillnad i potentialen att förtjocka de båda slammen då fördelningen av partiklar mellan förtjockat slam och rejektvatten varierade i varje försök. Däremot minskade TSS i rejektvattnet med högre dos av polymer medan samma samband inte gällde för TS i det förtjockade slammet där dosen polymer, efter en viss mängd, hade en begränsad påverkan på TS. En viktig aspekt som påverkade förtjockningskapaciteten i denna studie var igensättning av trumsilen. Centrifuger, som kommer att användas i framtida Henriksdals reningsverk, kommer inte uppvisa samma typ av störningar i driften. / To comply with future stricter regulations on treated wastewater and an increasing load on the system due to a growing population, the Stockholm Vatten och Avfall Company (SVOA) is upgrading the Henriksdal wastewater treatment plant within the project Stockholm’s Future Wastewater Treatment (SFA). One of the main changes in the future plant is the introduction of MBR-treatment, where sludge and water will be separated through the use of membranes. This separation will change the composition of the sludge by removing a larger fraction of particles from the effluent than what can be achieved in conventional sedimentation basins. Hammarby Sjöstadsverk operates a pilot plant with a MBR-process, where the technology is evaluated before the implementation in the future Henriksdal wastewater treatment plant. This study examines the difference in the sludge characteristics, i.e. sedimentation, filterability, and the potential for thickening of excess sludge from the MBR-process in Hammarby Sjöstadsverk (ÖS-MBR) and from the activated sludge process in the current Henriksdal wastewater treatment plant (ÖS-CAS). Furthermore, a mass balance and a sensitivity analysis has been used within this study. The study aimed at providing decision support for optimisation of the sludge treatment at the future Henriksdal wastewater treatment plant once the MBR process is implemented. The results of this study show that the characteristics of ÖS-MBR and ÖS-CAS differ considerably in total solids (TS), total suspended solids (TSS) and filterability (TTF). No difference in sludge volume index (SVI) could be verified between the two types of sludges. After thickening in a rotary drum screen with different doses of polymer, the TSS in the reject water was higher for the ÖS-MBR than the ÖS-CAS. This difference indicates that particles in ÖS-MBR are less attracted to the particular thickening polymer used, than the particles in ÖS-CAS. Therefore, it is important to select the correct type of polymer when thickening ÖS-MBR in order to reach the target TSS of 1000 mg/L in the reject water. In addition, the thickened ÖS-MBR showed higher TS than ÖS-CAS. This could indicate that ÖS-MBR would be easier to thicken; however, this is not confirmed by the mass balances. In the end, this study could not conclusively show any trend in the level of thickening between the two types of sludges because the distribution of particles varied in each trial. Nevertheless, while a higher dosage of polymer evidently reduced the TSS in the reject water, the same was not true for the TS in the thickened sludge, which seems to be less affected by the dose of polymer after a certain level. An important consideration in this study was the clogging of the drum screen. However, centrifuges, which will be used in the future Henriksdal wastewater treatment plant, do not have the same operational problems.

O objetivo deste estudo foi analisar o desempenho de um sistema de captação e tratamento de água do rio Sarapuí, por meio de uma estação de tratamento composta por um sistema de pré-tratamento convencional, ligado a um sistema de separação por membranas de osmose inversa, no Município de Belford Roxo RJ, instalado para fornecer água de processo a instalações industriais. Foi verificado que a água captada encontra-se em condição bastante degradada e que a unidade de tratamento removeu, em média, 97% do teor dos poluentes presentes na água, enquadrando-a nos parâmetros requeridos pelo processo industrial. Foi possível comprovar que o processo de separação por osmose inversa pode ser utilizado em escala industrial, proporcionando ganhos econômicos consideráveis, além de evitar o consumo de água potável para fins de processos industriais e, ainda, contribuir para a retirada de carga orgânica de uma fonte degradada / The objective of this study was to analyze the performance of a system to capture and treat water from Sarapuí river through a treatment system consisting of a conventional pré-treatment stage, linked to a reverse osmosis separation system membranes, in the city of Belford Roxo - RJ, installed to provide process water for industrial plants. It was found that the water is captured in highly degraded condition and the treatment plant removed an average of 97% of the pollutants in the water, fitting the parameters required by the industrial process. It could be demonstrated that the separation process by reverse osmosis can be used on an industrial scale, providing significant economic gains, and avoid the consumption of potable water for industrial processes and also contribute to the removal of organic pollutants from a degraded source

The Reconstruction of the Central Wastewater Treatment Plant in Prague constitutes a fundamental challenge for the Czech capital city of Prague. The existing wastewater treatment plant is obsolete and fails to comply with limits set forth by the Council Directive 91/271/EEC concerning urban waste-water treatment. Thus, it is necessary to build a new waterline and reconstruct the old one. As such a project would be financially demanding, its implementation is dependent upon a subsidy from the EU Operational Programme "Environment". There are also more variants of the reconstruction of the Central Wastewater Treatment Plant in Prague. In the thesis, the author compares the contemplated options of re-building and reconstruction of the Central Wastewater Treatment Plant in Prague. He also examines the influence of negotiations with European Commission representatives and of the amount of the subsidy upon the choice of the final option. A hypothesis of the study is that due to the subsidy policy creates pressure on the final form of the reconstruction of the Prague Central Wastewater Treatment Plant, which directly interact its economic efficiency.

Grande parte do lodo gerado em ETAs no Brasil ainda é disposta em rios ou em aterros sanitários. Contudo, principalmente em grandes centros urbanos, condições de licenciamento ambiental restritivas e custos logísticos crescentes tem levantado interesse em usos benéficos para esse resíduo. Um obstáculo para a mudança de paradigma recai no fato de que muito raramente operadores e projetistas de ETAs nacionais conseguirem prever, com algum grau de confiabilidade, a massa e volume de resíduos produzidos pelo tratamento da água bruta. Geralmente, usa-se para esse fim fórmulas empíricas, que relacionam a produção de lodo à concentração de sólidos em suspensão totais (SST) na água bruta e à dosagem de produtos químicos. Os objetivos deste trabalho são: comparar o desempenho de dois dos principais métodos quantitativos de estimativa de produção de lodo o método de fórmulas empíricas, e o do balanço de massa; investigar a prática disseminada de se estimar a concentração de sólidos em suspensão totais na água bruta por meio de modelos de regressão linear com a turbidez como variável independente; e delinear condições para a aplicação dessa correlação. Foram utilizados dados de seis ETAs de ciclo completo operadas pela SABESP (ABV, Alto Cotia, Cubatão, Guaraú, Franca e Presidente Prudente), além de dados de monitoramento de 130 estações de monitoramento de águas superficiais da CETESB. Os resultados sugerem que a identificação de correlações significativas entre concentração de SST e turbidez é elusiva, e não constitui tarefa trivial. Do universo de 130 estações da CETESB, somente 7 apresentaram correlação significativa; das ETAs, somente Presidente Prudente. Modelos de regressão alternativos utilizando outras variáveis (cor, vazão média mensal e mês), combinadas com a turbidez ou isoladamente, foram desenvolvidos. Somente a inclusão do mês como variável categórica foi capaz de aumentar o poder explicativo do modelo baseado exclusivamente na turbidez, sugerindo que a relação entre turbidez e concentração de SST é variável sazonalmente. Mediante a comparação com balanços de massa, foram identificados alguns fatores que afetam o poder de predição da fórmula empírica desenvolvida pela American Water Works Association, algumas vezes de maneira drástica. Em geral, conclui-se que o uso de fórmulas empíricas principalmente em conjunto com modelos de regressão entre concentração de SST e turbidez possa não ser recomendável. / Most of the water treatment plant (WTP) residuals generated in Brazil is still discharged in water bodies, or disposed of in landfills. However, especially in large urban areas, ever stringent conditions for environmental permits e rising logistical costs have put into focus beneficial uses for those residuals. A major obstacle for paradigm change in that aspect lies in the fact that very rarely water treatment plant operators and designers are able to predict with some degree of certainty the mass and volume of residuals produced by the treatment process. Usually, empirical formulas are used for that end, which relates the residuals production rate to the concentration of total suspended solids (TSS) in the raw water, and the chemicals dose. The objectives of this work are: to compare the performance of two of the main quantitative estimation methods for residuals production the empirical formulas and the mass balance; to investigate the widespread practice of estimating the concentration of TSS using turbidity as a surrogate; and to identify the conditions under which such procedure is acceptable. For that end, data from six WTPs operated by SABESP (ABV, Alto Cotia, Cubatão, Guaraú, Franca e Presidente Prudente), plus 130 surface water monitoring stations operated by CETESB, was analyzed. Alternative regression models, employing other independent variables (color, average monthly flow and month) singly or in combination with turbidity, were developed. Only the inclusion of the month as a categorical variable was capable of enhancing the explaining power of the turbidity model, suggesting that the relation between turbidity and TSS concentration is seasonally variable. The results suggest that identification of such significant correlations between TSS concentration and turbidity is elusive at best, and doesn\'t amount to a trivial task. Out of the universe of 130 monitoring stations, in only 7 a good degree of correlation was found; of the WTPs, that was the case only in Presidente Prudente. Through the comparison with the mass balances, some factors that affect the predictive power of the American Water Works Association sometimes drastically a were identified. In general, it is concluded that the use of empirical formulas especially when combined with turbidity and TSS concentration regression models may not be recommended.

The environmental occurrence and behaviour of the brominated flame retardant (BFR) decabromodiphenyl ethane (dbdpe) has only been studied to a limited extent. It is structurally similar to decabromodiphenyl ether (decaBDE), which makes it conceivable that dbdpe may also become an environmental contaminant of concern. A method for environmental analysis and comparative assessments of dbdpe and decaBDE was developed. Both BFRs were studied in: a mass balance of the Henriksdal WWTP in Stockholm (Paper I); an international survey of sewage sludge (Paper II); sediment along a transect from Henriksdal WWTP to the outer archipelago of Stockholm and from isolated Swedish lakes (Paper III); and a benthic food web from the Scheldt estuary (Paper IV). Dbdpe was found in sludge from every country surveyed, indicating that it may be a worldwide concern. The WWTP mass balance showed that virtually all of the BFRs were transferred from wastewater to sludge. A small fraction was emitted via the effluent, confirming emissions to the aquatic environment. In the marine sediment, the BFR levels close to the WWTP outfall were high. They decreased along the transect to low levels in the outer archipelago. The study of lake sediment showed a widespread presence of dbdpe in the Swedish environment and provided evidence that it originates from long range atmospheric transport. In the food web, dbdpe did bioaccumulate to a small extent which was similar to decaBDE. The transfer of the BFRs from sediment to benthic invertebrates was low, while transfer from prey to predator was higher. Biodilution was observed rather than biomagnification. This work suggests that the persistence, the susceptibility to long range atmospheric transport, and the potential for bioaccumulation are similar for dbdpe and the regulated decaBDE that it is replacing. Thus, there is a risk that a problematic environmental pollutant is being replaced with a chemical that is equally problematic. / At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 3: Submitted. Paper 4: Manuscript.

Många sjöar är idag påverkade av mänsklig aktivitet, bland annat är 1 % av Sveriges sjöar eutrofierade, däribland Ekoln. Ekoln är en stor sjö i Uppsala län söder om Uppsala som länge varit eutrofierad. Fyrisån och Örsundaån är de största inflödena till Ekoln och Sävjaån är ett betydande biflöde till Fyrisån. Kungsängsverket är Uppsalas reningsverk och har sitt utlopp i Fyrisån och som ett led i att minska eutrofieringen byggdes fosforreningen ut 1972. Fosforhalterna i Ekoln sjönk och algblomningarna blev färre. Kvävereningen byggdes ut 1999 och i detta arbete utvärderas detta reningssteg.   Hypotesen är att när ammonium minskar i bottenvattnet kommer syrgasförhållandena att förbättras på grund av minskad ammoniumnedbrytning som förbrukar syrgas. Med ökad halt syrgas är det känt sedan tidigare studier att den interna fosforbelastningen och algblomningen minskar.   För att undersöka om det skett en signifikant minskning av näringsämnen i intransporten till Ekoln och av halterna i Ekoln utfördes statistiska test av ämnena för perioden före och perioden efter införandet av kväverening. Intransporterna modellerades även i StormTac.   Resultatet visar att det skett en minskning av kväve- och ammoniumtransport och en ökning av fosfor-, fosfat- och TOC-transport. I Ekoln har en minskning påvisats i ammonium-, totalfosforhalt och en ökning i fosfat- och TOC-halt. Ammoniumhalten har minskat i bottenvattnet så den minskade intransporten av ammonium gett en effekt. Fosfor- och fosfathalten har inte förändrats signifikant i bottenvattnet, men det har skett en viss minskning av fosfor och en viss ökning av fosfat i Ekoln perioden 1990-1998 till 2000-2010. Även syrgashalten har ökat i bottenvattnet.   Att det inte skett signifikanta förändringar i fosfor, fosfat och syrgas tyder på att intransporten till vattenmassan inte förändrats. Ökade TOC-halter leder till ökad nedbrytning där syrgas förbrukas i bottenvattnet. Det är möjligt att situationen sett ännu värre ut i Ekoln om inte kväveutsläppen minskat.

Στην παρούσα μελέτη πραγματοποιήθηκε εκτίμηση της τοξικότητας των τελικών εκροών πριν και μετά το στάδιο της απολύμανσης (με τη χρήση της μεθόδους της χλωρίωσης) από το σταθμό βιολογικής επεξεργασίας των αστικών αποβλήτων της Πάτρας με την χρήση βιοδεικτών (biotest). Η μελέτη των τοξικών επιπτώσεων αυτών των εκροών και από τα δύο στάδια πραγματοποιήθηκε σε οργανισμούς-Βιοδείκτες τόσο των γλυκών όσο και αλμυρών υδάτων, όπως οι οργανισμοί Thamnocephalus platyurus και Artemia franciscana (με τη μορφή βιοτέστ Thamnotoxkit F και Artoxkit MTM αντίστοιχα), όσο και σε φυτικά είδη, όπως τα Sorghum saccharatum, Lepidum sativum και Sinapis alba (με τη μορφή Phytotoxkit). Επιπλέον έγινε ανίχνευση του μικροβιακού φορτίου πριν και μετά το στάδιο της χλωρίωσης, για την εκτίμηση της αποτελεσματικότητας της μεθόδου απολύμανσης των εκροών, καθώς και χημική ανάλυσή τους. Σύμφωνα με τα αποτελέσματα της παρούσας μελέτης, οι τελικές εκροές υγρών αποβλήτων που καταλήγουν στο στάδιο της απολύμανσης, με τη μέθοδο της χλωρίωσης παρουσιάζουν μεγάλες διακυμάνσεις τόσο στις φυσικοχημικές παραμέτρους και στη συγκέντρωση βαρέων μετάλλων που μετρήθηκαν, όσο και στην τοξικότητα που μπορεί να επιφέρουν στους οργανισμούς που χρησιμοποιήθηκαν. Τα αποτελέσματα της παρούσας μελέτης έδειξαν την αποτελεσματικότητα της μεθόδου όσο αφορά τη μείωση του μικροβιακού φορτίου των τελικών εκροών. Αντίθετα, η μελέτη τοξικότητας των τελικών εκροών με τη χρήση οργανισμών τόσο του γλυκού όσο και του αλμυρού νερού (Thamnocephalus platyurus και Artemia franciscana αντίστοιχα), καθώς και σε φυτικούς οργανισμούς (Sorgum saccharatum, Sinapsis alba και Lepidum sativum) έδειξε σημαντικές εποχικές μεταβολές στην επαγωγή τοξικών φαινομένων. Συγκεκριμένα, οι εκροές (μετά το στάδιο της χλωρίωσης effluents) φαίνεται να είναι λιγότερο τοξικές για τους οργανισμούς του αλμυρού νερού, συγκριτικά με τις τοξικές επιπτώσεις που προκαλούν οι εκροές πριν το στάδιο της χλωρίωσης (influents). Αντίθετα, οι εκροές που προκύπτουν μετά το στάδιο της χλωρίωσης παρουσιάζουν μεγαλύτερη τοξικότητα σε οργανισμούς του γλυκού νερού, σε σχέση με τις επιπτώσεις που προκαλούν οι εκροές πριν το στάδιο της χλωρίωσης, ενώ παρατηρήθηκε σημαντική αναστολή της αυξητικής ικανότητας των ειδών Sorgum saccharatum και Sinapsis alba σε κάθε περίπτωση. Συμπερασματικά, από τα αποτελέσματα της παρούσας μελέτης, φαίνεται η αποτελεσματικότητα της μεθόδου απολύμανσης των τελικών εκροών, όσο αφορά την απαλλαγή τους από μολυσματικούς παράγοντες, αλλά αναδεικνύονται τα προβλήματα τοξικότητας που μπορεί να επιφέρουν οι τελικές εκροές σε οργανισμούς των τελικών υδάτινων αποδεκτών (γλυκό και αλμυρό νερό), καθώς και η αναποτελεσματικότητα της χρήσης των τελικών εκροών σε δραστηριότητες όπως η άρδευση, λόγω της αναστολής που προκαλεί η χρήση τους σε φυτικούς οργανισμούς. / In this study was estimated the toxicity of the final effluents before and after the stage of disinfection (using the method of chlorination) in the wastewater treatment plant of Patras using bioindicators (biotest).The study of the toxic effects of these effluents and of the two stages was performed on organisms bioindicators both in freshwater and salt water, such as Thamnocephalus platyurus and Artemia franciscana (in the form of biotest Thamnotoxkit F and Artoxkit MTM respectively) and on plant species such as Sorghum saccharatum, Lepidum sativum and Sinapis alba (in the form of Phytotoxkit). Moreover the treated effluents were tested for microbiological parameters before and after the stage of chlorination, to assess the effectiveness of the method of disinfection of effluents, and also a chemical analysis was performed. According to the results of this study, the final effluents of wastewater that end in the process of disinfection, with the method of chlorination, vary widely both in physicochemical parameters and heavy metals that were measured, and as well the toxicity that can cause to organisms used. The results of this study showed the effectiveness of the method as regards reducing the microbial load of the final effluents. Instead, the study of final effluents toxicity using organisms of both fresh and saltwater (Thamnocephalus platyurus and Artemia franciscana, respectively) and in plant organisms (Sorgum saccharatum, Sinapsis alba and Lepidum sativum) showed significant seasonal changes in the induction of toxic reactions. Specifically, the effluents (after-chlorination effluents) seem to be less toxic for organisms of salt water, compared with the toxic effects caused by effluents before the stage of chlorination (influents). However, the effluents after the stage of chlorination are toxic in freshwater organisms compared to the effects caused by effluents before the stage of chlorination, while there was significant inhibition of growth capacity of species Sorgum saccharatum, Sinapsis alba in each case. In conclusion, the results of this study show the effectiveness of the method of disinfection of final effluents, as regards the discharge from contaminants, but highlighted the problems of toxicity that the final effluents can cause to organisms in the final water receiver (fresh and salty water), and the inefficiency of using of final effluents in activities such as irrigation, due to the inhibition caused by their use in plant organisms.

Χωροθέτηση μονάδας επεξεργασίας ΑΣΑ σε συνδιασμό με τον απαραίτητο ΧΥΤΥ, με μικτό ακέραιο γραμμικό προγραμματισμό, για τη βελτιστοποίηση των ακολουθούμενων διαδρομών των απορριμματοφόρων προς την μονάδα επεξεργασίας και απο την μονάδα προς τον ΧΥΤΥ.Εγινε με εφαρμογή GIS στη Μεσσηνία. / The current thesis is about optimum siting of a MSW treatment plant combined with a landfill for residues based on mixed integer linear programming (MILP) and GIS methodology.