Abstract Water in the coastal areas of Ostrobothnia typically contains high levels of humus, iron and manganese. Organic matter and iron contained in groundwater form compounds that make water treatment more difficult. The treatment process of such water usually resembles that used in a traditional chemical water treatment plant. This kind of chemical treatment process is, however, an expensive alternative in view of the resources of a small or a medium-sized treatment plant. The aim of this research was to find out whether ozonation and oxidation with hydrogen peroxide can be used for the treatment of water containing high amounts of organic matter. Ozone is rather widely used in surface water plants for the final treatment of water. The most common applications include the disinfection and oxidation of substances that cause unpleasant taste and odour in water. This research deals with the use of ozone for the treatment of groundwater containing iron and manganese. Since ozone is a powerful oxidizer, it is able to oxidize iron and manganese contained in water into an insoluble form. Also a noticeable amount of organic matter is precipitated in the same process. However, in some of the researched cases the precipitate was so fine that it was impossible to separate it with traditional methods. A combination of ozonation and microfiltration proved to be a successful form of treatment when dealing with this type of water. Ozonation increased the AOC of water in all of the researched cases. The content of bromide is reasonably low in Finnish groundwater. The median measured in coastal Northern Ostrobothnia was 0.025 mgl-1. With the used ozone dosage, the bromate formed in the process stayed below the limit value of 10 μgl-1. Therefore it can be stated that the formation of bromate does not hinder ozone treatment from becoming a more common form of water treatment in Finland. However, the formation of bromate must be taken into consideration, especially if ozonation is made in hig pH. Hydrogen peroxide can be used as an alternative chemical in the oxidation and precipitation processes of iron in groundwater. The chemical is used for the oxidation of iron before filtration. If the formed precipitate is fine, microfiltration or flocking chemical can be used to remove the precipitate. / Tiivistelmä Pohjanmaan rannikkoseudun pohjavesille on tyypillistä korkeat rauta- ja mangaanipitoisuudet yhdistettynä suureen humuspitoisuuteen. Orgaaninen aine muodostaa pohjaveden raudan kanssa yhdisteitä, jotka vaikeuttavat vedenkäsittelyn toimintaa. Kyseisten vesien käsittely lähestyy yleensä perinteistä kemiallista pintavesilaitosta. Kuitenkin pienten ja keskisuurten vesilaitosten resursseihin nähden täydellinen kemiallinen käsittely on kallis vaihtoehto. Tämän tutkimuksen tarkoituksena oli selvittää otsonoinnin ja vetyperoksidihapetuksen käyttökelpoisuutta näiden runsaasti orgaanista ainetta sisältävien vesien käsittelyssä. Otsonoinnin yleisimmät sovellutukset ovat hajua ja makua aiheuttavien aineiden hapettaminen ja desinfiointi. Tässä tutkimuksessa selvitettiin otsonin käyttöä rauta- ja mangaanipitoisten pohjavesien käsittelyssä. Otsoni saa voimakkaana hapettimena vedessä olevan raudan ja mangaanin hapettumaan ei liukoiseen muotoon. Samalla kerasaostui huomattava määrä orgaanista ainetta. Kuitenkin muodostuva sakka on joissain tapauksissa niin hienojakoista, että sen erottaminen perinteisin menetelmin on mahdotonta. Näiden ns. ongelmavesien käsittelyssä saatiin hyviä tuloksia otsonoinnin ja mikrosuodatuksen yhdistelmällä. Otsonointi nosti huomattavasti kaikkien tutkittujen vesien AOC-pitoisuutta. Bromidipitoisuudet suomen pohjavesissä olivat kohtuullisia. Pohjanmaan rannikkoseudun pohjavesien bromidipitoisuuksien mediaani oli 0,025 mgl-1. Kaikilla vesillä käytännön otsoniannostuksilla syntyvät bromaattimäärät alittivat 10 μgl-1 raja-arvon. Bromaattiongelma ei ole este otsonikäsittelyn yleistymiselle Suomessa. Se on kuitenkin tiedostettava, varsinkin, jos otsonointi tehdään korkeassa pH:ssa. Vetyperoksidi on vaihtoehtoinen kemikaali pohjaveden raudan hapettamiseen ja saostamiseen. Vetyperoksidia voidaan käyttää raudan saostamiseen ennen suodatusta. Mikäli muodostuva sakka on hienojakoista, voidaan sakanerotus tehdä mikrosuodatuksella tai käyttää hyväksi flokkauskemikaaleja.

Tato práce se zabývá studiem vlivu kaolinitových ástic (reprezentujících látky tvo ící zákal vody) a peptidové/proteinové složky COM (Cellular Organic Matter) produkovaných sinicí Microcystis aeruginosa na velikost, strukturu a tvar tvo ených agregát v prom nných hydrodynamických podmínkách (gradientu rychlosti) p i úprav vody. Agregace probíhala v Taylor-Couettov reaktoru. Koagulace vybraných typ zne iš ujících p ím sí (kaolinitové ástice, COM peptidy/proteiny a jejich sm s) probíhala pomocí síranu hlinitého a síranu železitého. Vzniklé agregáty byly hodnoceny ve fázi homogenní velikosti (steady state) po 60 min míchání pomocí ukazatel : velikost (polom r) agregát , fraktální dimenze D2 a Dpf a velikostní distribuce. Bylo zjišt no, že velikost agregát je závislá na typu koagula ního inidla, typu koagulované p ím si a aplikovaném gradientu rychlosti. S rostoucím gradientem rychlosti se velikost agregát zmenšuje. Železité koagula ní inidlo produkuje v tší agregáty než hlinité koagula ní inidlo. Podle p ím si roste velikost agregát v po adí kaolinit < COM < kaolinit + COM. Struktura agregát se stává kompaktn jší s gradientem rychlosti. P i použití hlinitého koagula ního inidla vznikají ve srovnání s inidlem železitým kompaktn jší agregáty (mají vyšší hodnotu D2). Kompaktnost agregát klesá v po adí...

M.Sc. (Environmental Management) / In South Africa, there are practically no freshwater lakes. Therefore, exploitable water supplies are confined to rivers, artificial lakes behind dams, and groundwater. The many demands for water, and the erratic flow of most South African rivers, have led to the creation of artificial lakes and dams, i.e. impoundments on all the major rivers, in order to stabilise flow and therefore guarantee annual water supply. Cyanobacterial bloom formation in freshwater sources, such as rivers, lakes, dams and reservoirs are known to occur throughout the world. In South Africa, the occurrence of cyanobacteria has also been recorded with the best known being the bloom of the hyper-eutrophic Hartbeespoort Dam. In South Africa specifically, cyanobacteria are mostly seasonally driven. Species that are known to cause bloom formation are Microcystis sp., Anabaena sp., Oscillatoria sp. and Cylindrospermopsis sp. These species are known to produce cyanotoxins that cause health problems in animals and humans, but also produce taste and odour problems in drinking water, if not treated effectively. In most cases where cyanobacteria blooms have been known to occur, it also enters source water for drinking water purification plants. Because source water containing cyanobacteria and the effect it has on the consumer, environment and animals, it is thus important to identify the dominant algae species. Cyanotoxin drinking water guidelines must be developed and implemented and a management plan for the Water Treatment Plant must be produced, to ensure that the risk of human exposure to the cyanotoxins are minimised. The present study focuses on the Vaalkop Dam from which raw water is abstracted and treated by the Magalies Water Vaalkop Water Treatment Plant (MWVWTP) to produce potable water. The source water abstracted from the Vaalkop Dam can contain high numbers of cyanobacteria as well as cyanotoxins that must be removed by the MWVWTP during potable water purification to ensure compliance to water quality standards. The overall objective of the study is to investigate the occurrence of cyanobacteria and cyanotoxins in the Vaalkop Dam at the point where the source water is abstracted for drinking water purification.

Access to safe drinking water is an important health factor in many developing countries. Studies have shown that unsafe drinking water and poor sanitation practices leads to diarrheal disease, which is one of the leading causes of death of children under five in developing countries. Provision and proper use of household water filters have been shown to effectively improve health. This thesis is focused on the refinement and validation of algorithms for data collected from pressure transducer sensors that are used in household water filters (the Vestergaard Frandsen LifeStraw Family 2.0) deployed in Rwanda by the social enterprise DelAgua Health. Statistical and signal processing techniques were used to detect the use of the LifeStraw water filters and to estimate the amount of water filtered at the time of usage. An algorithm developed by Dr. Carson Wick at Georgia Institute of Technology was the baseline for the analysis of the data. The algorithm was then refined based on data collected in the SweetLab at Portland State University, which was then applied to field data. Laboratory results indicated that the mean error of the improved algorithm is 11.5% as compared with the baseline algorithm mean error of 39%. The validation of the algorithm with field data yielded a mean error of 5%. Errors may be attributed to real-world behavior of the water filter, electronic noise, ambient temperature, and variations in the approximation made to the field data. This work also presents some consideration of the algorithm applied to soft-sided water backpacks.

Orientador: Ricardo de Lima Isaac / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo / Made available in DSpace on 2018-08-18T11:03:55Z (GMT). No. of bitstreams: 1 Haak_Wando_M.pdf: 4830827 bytes, checksum: 311caf27f5b5da6d03f6312ef08d15bc (MD5) Previous issue date: 2011 / Resumo: Estações de tratamento de água (ETA) geram resíduos durante o processo de potabilização da água bruta. Esse resíduo onera as companhias de saneamento, no que tange o tratamento e disposição final. O tratamento do lodo é constituído de processos de separação sólido-líquido, cuja eficiência - quanto à maximização do teor de sólidos da torta (lodo desaguado) e melhor qualidade da água recuperada no processo - é dependente do adequado condicionamento químico, em geral obtido pela ação de polímeros. A super- dosagem ou a sub-dosagem desse produto ocasiona perda de qualidade, tanto da torta, quanto da água eliminada. Este trabalho tem como objetivo verificar através de estudo de bancada, a viabilidade técnica e econômica do condicionamento químico na adequação de processo de tratamento de lodo de ETA, visando melhor desempenho na fase de desaguamento, tendo em vista a disposição final dos resíduos gerados durante o tratamento. Foram relacionadas medidas de potencial redox com controle de dosagem e consumo de polímero catiônico de alto e muito alto peso molecular, de baixa, média e alta densidade de carga e polímero aniônico de alto peso molecular, com baixa e média densidade de carga, com e sem oxidação química com cloro e permanganato de potássio. Na investigação experimental os resultados referentes ao tempo de filtração, indicaram os polímeros catiônicos de alto peso molecular, de baixa e média e alta carga como sendo mais eficientes. Para valores de potencial redox entre -57mV e 75mV, os polímeros catiônicos, em sua maioria, apresentaram consumos de 6,0 a 10,0 (kg/tms), em lodo não oxidado. A oxidação do lodo com permanganato de potássio ou cloro para valores entre -11mV e +11mV foi significativa, com redução da dosagem de polímeros catiônicos para valores de 4,0 a 7,0 (kg/tms), proporcionando economia de 30%. Considerando-se as correlações encontradas, tendo em mãos, sondas confiáveis de pH e potencial redox, é possível automatizar um determinado sistema de dosagem para oxidação do lodo / Abstract: Water treatment plants (WTP) generate waste during the process of potabilization of raw water. This residue burdens the sanitation companies, with regard to treatment and final disposal. The sludge treatment process consists of solid-liquid separation, whose efficiency - as to maximize the solids cake (dewatered sludge) and better quality of the reclaimed water in the process - is dependent on proper chemical conditioning, usually obtained by action of polymers. Over dosage or under dosage of those products causes loss of quality of both, cake and eliminated water. The aim of this work is to verify the technical and economical feasibility of the chemical conditioning at the fitting of sludge treatment process at a WTP, through work bench study, aiming at better performance during the dewatering, looking at the treatment final discharge of residues. Measures of redox-controlled dispensing were related to consumption of cationic polymer of high and very high molecular weight, of low, medium and high charge density and anionic polymer of high molecular weight, of low and medium charge density, with and without chemical oxidation with chlorine and potassium permanganate. At the primary investigation of percolating time, the cationic polymers of high molecular weight with low, medium and high charge, proved to be more efficient. For potential redox values between -57mV and 75mV, most of the cationic polymers consumed from 6.0 to 10.0 (kg/tms), in non-oxidized sludge. There was a significant oxidation of sludge with potassium permanganate or chlorine for values between -11 and +11mV, reducing the dosage of cationic polymers to values from 4.0 to 7.0 (kg/tms), providing a 30% economy. Taking into account the correlations found, using reliable pH and redox potential probes, it is possible to automate a system of dosage for the sludge oxidation / Mestrado / Saneamento e Ambiente / Mestre em Engenharia Civil

Cette thèse se compose de deux parties. Dans la première partie, nous étudions les stratégies de temps minimum pour le traitement de la pollution dans de grandes ressources en eau, par exemple des lacs ou réservoirs naturels, à l'aide d'un bioréacteur continu qui fonctionne à un état quasi stationnaire. On contrôle le débit d'entrée d'eau au bioréacteur, dont la sortie revient à la ressource avec le même débit. Nous disposons de l'hypothèse d'homogénéité de la concentration de polluant dans la ressource en proposant trois modèles spatialement structurés. Le premier modèle considère deux zones connectées l'une à l'autre par diffusion et seulement une d'entre elles connectée au bioréacteur. Avec l'aide du Principe du Maximum de Pontryagin, nous montrons que le contrôle optimal en boucle fermée dépend seulement des mesures de pollution dans la zone traitée, sans influence des paramètres de volume, diffusion, ou la concentration dans la zone non traitée. Nous montrons que l'effet d'une pompe de recirculation qui aide à homogénéiser les deux zones est avantageux si opérée à vitesse maximale. Nous prouvons que la famille de fonctions de temps minimal en fonction du paramètre de diffusion est décroissante. Le deuxième modèle consiste en deux zones connectées l'une à l'autre par diffusion et les deux connectées au bioréacteur. Ceci est un problème dont l'ensemble des vitesses est non convexe, pour lequel il n'est pas possible de prouver directement l'existence des solutions. Nous surmontons cette difficulté et résolvons entièrement le problème étudié en appliquant le principe de Pontryagin au problème de contrôle relaxé associé, obtenant un contrôle en boucle fermée qui traite la zone la plus polluée jusqu'au l'homogénéisation des deux concentrations. Nous obtenons des limites explicites sur la fonction valeur via des techniques de Hamilton-Jacobi-Bellman. Nous prouvons que la fonction de temps minimal est non monotone par rapport au paramètre de diffusion. Le troisième modèle consiste en deux zones connectées au bioréacteur en série et une pompe de recirculation entre elles. L'ensemble des contrôles dépend de l'état, et nous montrons que la contrainte est active à partir d'un temps jusqu'à la fin du processus. Nous montrons que le contrôle optimal consiste à l'atteinte d'un temps à partir duquel il est optimal de recirculer à vitesse maximale et ensuite ré-polluer la deuxième zone avec la concentration de la première. Ce résultat est non intuitif. Des simulations numériques illustrent les résultats théoriques, et les stratégies optimales obtenues sont testées sur des modèles hydrodynamiques, en montrant qu'elles sont de bonnes approximations de la solution du problème inhomogène. La deuxième partie consiste au développement et l'étude d'un modèle stochastique de réacteur biologique séquentiel. Le modèle est obtenu comme une limite des processus de naissance et de mort. Nous établissons l'existence et l'unicité des solutions de l'équation contrôlée qui ne satisfait pas les hypothèses habituelles. Nous prouvons que pour n'importe quelle loi de contrôle la probabilité d'extinction de la biomasse est positive. Nous étudions le problème de la maximisation de la probabilité d'atteindre un niveau de pollution cible, avec le réacteur à sa capacité maximale, avant l'extinction. Ce problème ne satisfait aucune des suppositions habituelles (la dynamique n'est pas lipschitzienne, diffusion dégénérée localement hölderienne, contraintes d'état, ensembles cible et absorbant s'intersectent), donc le problème doit être étudié dans deux étapes: en premier lieu, nous prouvons la continuité de la fonction de coût non contrôlée pour les conditions initiales avec le volume maximal et ensuite nous développons un principe de programmation dynamique pour une modification du problème original comme un problème de contrôle optimal avec coût final sans contrainte sur l'état. / This thesis consists of two parts. In the first part we study minimal time strategies for the treatment of pollution in large water volumes, such as lakes or natural reservoirs, using a single continuous bioreactor that operates in a quasi-steady state. The control consists of feeding the bioreactor from the resource, with clean output returning to the resource with the same flow rate. We drop the hypothesis of homogeneity of the pollutant concentration in the water resource by proposing three spatially structured models. The first model considers two zones connected to each other by diffusion and only one of them treated by the bioreactor. With the help of the Pontryagin Maximum Principle, we show that the optimal state feedback depends only on the measurements of pollution in the treated zone, with no influence of volume, diffusion parameter, or pollutant concentration in the untreated zone. We show that the effect of a recirculation pump that helps to mix the two zones is beneficial if operated at full speed. We prove that the family of minimal time functions depending on the diffusion parameter is decreasing. The second model consists of two zones connected to each other by diffusion and each of them connected to the bioreactor. This is a problem with a non convex velocity set for which it is not possible to directly prove the existence of its solutions. We overcome this difficulty and fully solve the studied problem applying Pontryagin's principle to the associated problem with relaxed controls, obtaining a feedback control that treats the most polluted zone up to the homogenization of the two concentrations. We also obtain explicit bounds on its value function via Hamilton-Jacobi-Bellman techniques. We prove that the minimal time function is nonmonotone as a function of the diffusion parameter. The third model consists of a system of two zones connected to the bioreactor in series, and a recirculation pump between them. The control set depends on the state variable; we show that this constraint is active from some time up to the final time. We show that the optimal control consists of waiting up to a time from which it is optimal the mixing at maximum speed, and then to repollute the second zone with the concentration of the first zone. This is a non intuitive result. Numerical simulations illustrate the theoretical results, and the obtained optimal strategies are tested in hydrodynamic models, showing to be good approximations of the solution of the inhomogeneous problem. The second part consists of the development and study of a stochastic model of sequencing batch reactor. We obtain the model as a limit of birth and death processes. We establish the existence and uniqueness of solutions of the controlled equation that does not satisfy the usual assumptions. We prove that with any control law the probability of extinction is positive, which is a non classical result. We study the problem of the maximization of the probability of attaining a target pollution level, with the reactor at maximum capacity, prior to extinction. This problem does not satisfy any of the usual assumptions (non Lipschitz dynamics, degenerate locally H"older diffusion parameter, restricted state space, intersecting reach and avoid sets), so the problem must be studied in two stages: first, we prove the continuity of the uncontrolled cost function for initial conditions with maximum volume, and then we develop a dynamic programming principle for a modification of the problem as an optimal control problem with final cost and without state constraint.

A ocupação desordenada das bacias hidrográficas provocou a aceleração da eutrofização que, além de problemas meramente estéticos e paisagísticos, resulta na ocorrência de elevadas densidades de fitoplâncton com dominância de cianobactérias potencialmente tóxicas nos mananciais. Paralelamente ao envelhecimento e deterioração física das instalações, as tecnologias usuais de tratamento não reúnem condições para tratar adequadamente águas de mananciais onde ocorre aporte de substâncias químicas recalcitrantes como agrotóxicos, fertilizantes e disruptores endócrinos. O presente trabalho teve como objetivo estudar e avaliar a técnica da dupla filtração em leitos de pedregulho e areia, com pré ou interoxidação e adsorção com carvão ativado granulado e pulverizado, para a potabilização de água de reservatório eutrofizado com elevada densidade de cianobactérias - Açude Gargalheiras, Acari, semiárido do RN. A pesquisa constou de quatro fases: fase 01 caracterização físico-química e biológica contínua da água bruta do manancial e realização de ensaios estáticos de filtração direta em equipamento de jarteste e filtros de laboratório de areia, fase 02 - avaliação de pré-filtração ascendente em pedregulho com camadas filtrantes de diferentes granulometrias, fase 03 - comportamento da dupla filtração sob quatro taxas de filtração e quatro pré-filtros e fase 04 - estudo de arranjos da instalação piloto com pré e interoxidação e adsorção com carvão ativado granulado e pulverizado. Concentrações médias da série nitrogenada, fósforo total e ortofosfato solúvel enquadraram o Açude Gargalheira como eutrófico. Elevadas densidades de cianobactérias mostraram necessidade de monitoramento semanal do manancial (bioensaios de toxicidade e análise de cianotoxinas). Ensaios estáticos em bancada definiram dosagens de coagulante hidróxicloreto de alumínio entre 13 mg/L e 15 mg/L e pH de coagulação de 7,6, sob gradiente e tempo de mistura rápida de 700/s e 17 s; dosagens de oxidante (cloro) entre 2,0 mg CL 2.L-1 e 3,0 mg CL2.L-1 e tempo de oxidação de 20 minutos, com eliminação da acidificação e dosagem de CAP de 15 mg/L com tempo de adsorção de 30 minutos. FAP4 (pré-filtro com camada filtrante entre 2,0 mm e 3,2 mm) apresentou menores médias de turbidez e cor aparente remanescentes. Taxa de filtração entre 160 m3.m-2.dia-1 e 200 m3.m-2.dia-1 foi a faixa escolhida pela melhor performance e menores custos financeiros de implantação e reforma e ampliação de unidades existentes. Dupla filtração com granulometria, espessura das camadas suporte e filtrante e taxas de filtração escolhidas e nas condições operacionais aplicadas, mostrou bom desempenho em relação à remoção de flocos de células de cianobactérias e, consequentemente, de microcistinas totais-LR. As remoções de cianobactérias nos pré-filtros variaram entre 52% (FAP2) e 96% (FAP4), representando densidades remanescentes entre 20.000 células/mL e 13.000 células/mL. Os filtros descendentes de areia atuaram como sistemas de polimento final com remoção na faixa de 61% a 98% (9.400 células/mL a 5.800 células/mL). Oxidação com cloro (inter e pré-oxidação), com residual de cloro livre da ordem de 0,1 mg/mL, associada à adsorção com CAP e CAG produziu efluentes finais com qualidade aceitável quanto aos níveis de TAM, turbidez e cor verdadeira. Arranjos de pré e interoxidação, dupla filtração e adsorção com CA (exibiram melhores desempenhos de remoção de MON, COT, ABS254, cor aparente verdadeira e turbidez e foram eficientes para assegurar a qualidade dos efluente finais especialmente em relação à remoção de MCT-LR e TAM: efluentes da colunas FCAG tiveram concentração de MCT-LR reduzida, consistentemente, para valores inferiores a 1,0 &#181;g/L. / Disordered basins occupation provoked acceleration of eutrophication, which besides purely aesthetic and landscaping problems, results in occurrence of high phytoplankton densities with potentially toxic cyanobacteria dominance. Alongside physical aging and consequent deterioration of installations, usual treatment technologies do not provide adequate conditions for treating water from reservoirs where occurs recalcitrant chemicals such as pesticides, fertilizers and endocrine disrupters. This work aimed to evaluate double filtration in gravei and sand filters, pre and interoxidation and adsorption with powdered and granulated activated carbon, for water potabilization from eutrophic reservoir with high cyanobacteria density - Gargalheira Weir, Acari, semi-arid region of RN Brazil. The survey consisted of four phases: phase 1 - continuous physic-chemical and biological raw water characterization and static tests in jartest equipment and direct filtration with laboratory sand filters, phase 2 - evaluation of up flow prefiltration with different graded layers, phase 03 - double filtration behavior under four filtration rates and four pre filters and phase 04 - double filtration arrangements study with pre and interoxidation and adsorption with PAC and GAC columns. The average concentrations of nitrogen series, total phosphorus and soluble orthophosphate classified the Gargalheira Weir as eutrophic. High cyanobacteria densities showed the need for weekly monitoring (toxicity bioassays and cyanotoxins analysis). Static bench tests established aluminum hidroxicloride dosages from 13 mg/L to 15 mg/L and pH coagulation 7.6, with flash mixing gradient 700/s and contact time 17 s; oxidant (chlorine) dosages 2.0 mg CL2.L-1 and 3.0 mg CL2.L-1 and 20 minutes for oxidation time, with acidification elimination; 15 mg/L CAP dosage with 30 minutes adsorption time. FAP4 (pre filter with layer size 2.0 mm - 3.2 mm) had lower average turbidity and apparent color remnants. Flow rate between 160 m3.m-2.dia-1 and 200 m3.m-2.dia-1 was chosen for its performance and lower financial costs of deployment, reform and expansion of existing units. Double filtration with particle size, thickness of layers and filter support and filtration rates choosed under operational conditions applied showed good performance regarding removal of cyanobacteria cells flakes and total microcystin-LR. Cyanobacteria removal in pre filters ranged from 52% (FAP2) and 96% (FAP4), representing remaining densities between 20,000 and 13,000 cells/mL. Down flow sand filters done final polishing with removal 61% to 98% (9,400 cells/mL to 5,800 cells/mL). Oxidation with chlorine in both inter and pre oxidation with free chlorine residual of about 0.1 mq/L, associated with GAC and PAC adsorption produced final effluent with acceptable quality for TAM, turbidity and true color levels. Pre and interoxidation arrangements with double filtration and GAC adsorption as post treatment stage showed betler performances in removal MON, TOC, ABS254, true and apparent color and turbidity and exhibitid efficience to ensure final effluent quality in particular MCT-LR and TAM removing: GAC columns effluents had reduced MCT-LR concentrations consistently to less than 1.0 &#181;g/L.

Résumé : La Bretagne (France) est une région agricole où les polluants émergeants sont très susceptibles d’atteindre les eaux de surfaces. La surveillance institutionnelle montre que les sous-produits d’herbicides sont la principale pollution des eaux de surface, dans une région où 80 % des eaux potables sont produites à partir de ressources superficielles. Le comportement dans l’environnement des sous-produits d’herbicides est mal connu et, pour certains d’entre eux, les contributions de leurs différentes sources font toujours débat. Dans l’est de la Bretagne, le bassin versant de la Vilaine (10 500 km²) est d’un grand intérêt pour la recherche, car il abrite une importante usine de potabilisation (100 000 m3/j) à son extrême aval. Dans ce contexte, cette étude vise à (i) cartographier le bassin versant, (ii) évaluer la contamination et ses variations spatiales et saisonnières, (iii) comprendre les conditions favorables à l’export vers les eaux de surface, (iv) étudier les sources et le devenir de l’AMPA (acide aminométhyl phosphonique) dans les eaux usées, (v) explorer le procédé d’ozonation pour un sous-produit récalcitrant aux traitements de l’eau potable. Cette thèse consiste en trois chapitres : une revue de la littérature sur l’occurrence et le devenir des herbicides et leurs sous-produits dans les eaux de surface, eaux usées, et eau potable; le matériel et méthodes incluant, la sélection des composés d’intérêt, la stratégie d’échantillonnage, la description des méthodes d’analyses et d’assurance qualité, les outils statistiques; les résultats d’occurrence et de comportement des sous-produits d’herbicides dans les différentes eaux étudiées. Ces travaux se concluent sur un contexte plus large avec des perspectives pour acquérir une meilleure compréhension des sources et des facteurs influençant l’occurence des sous-produits d’herbicides dans les différentes eaux, dans le but d’améliorer la qualité des ressources. / Abstract : Brittany (France) is an agricultural region, where emerging pollutants are highly at risk to reach surface waters. Legal monitoring shows that herbicides metabolites are the main pollution of surface waters, in a region where 80 % of drinking water is produced with surface waters. The environmental behavior of herbicides metabolites is badly known and, for some of them, the contributions of their different sources are still debated. In east Britany, the Vilaine watershed (10 500 km²) is of great research interest, as a large drinking water treatment plant (100 000 m3/day) is located at the extreme downstream of it. In this context, this study aims to (i) map the watershed, (ii) evaluate the contamination and its spatial and seasonal variations, (iii) understand the favoring conditions resulting in metabolites export towards surface water, (iv) study sources and fate of AMPA (aminomethylphosphonic acid) in wastewaters, (v) explore ozonation treatment of a resistant metabolite in drinking water This thesis consists of three chapters: a review of the literature on herbicides and their metabolites occurrence and fate in surface waters, wastewaters, and drinking water; the materials and methods including, selection of compounds of interest, sampling strategy, description of the methods of analysis and quality assurance, statistical tools; the results of herbicides metabolites occurrences and behavior in the different waters studied. This work concludes on a broader context by providing perspectives to gain a better understanding of the sources and the factors influencing herbicides metabolites occurrences in the different waters, in order to improve the quality of water resources.

The purpose of this Bachelor thesis was to establish a method for determining the chemical oxygen demand (COD) fractionation in wastewater from cruise liners. COD fractions of interest were soluble biodegradable (SS), particulate biodegradable (XS), soluble unbiodegradable (SI) and particulate unbiodegradable (XI). Three types of wastewater (gray water, black water and permeate) were analysed and a method with a physiochemical approach was established. The method was originally elaborated by Jun Wu et al in the study “Wastewater COD biodegradability fractionated by simple physical–chemical analysis” (2014) Chemical Engineering Journal[ES1] [JB2]  258, p 450-459. The method was also used for comparison reasons of the COD fractionation in permeate before and after advanced treatment with nanofiltration and ozonation. Total COD in permeate was almost half of the initial value after nanofiltration and XI was eliminated. After ozonation no significant difference was observed neither in total COD concentration or fractionation pattern. The conclusion is that this method to determine the COD fractions has potential but it needs further optimization in form of adjusting the methods matrix specifically based on wastewater from cruise liners. / NAUTEK

>Magister Scientiae - MSc / Environmental pollution is a major threat to all life, which needs to be addressed. Heavy metals are well-known environmental pollutants due to their toxicity and, persistence in the environment toxicity for living organisms and having a bioaccumulative nature. Environmentally, the most common hazardous heavy metals are: Cr, Ni, Cu, Zn, Cd, Pb, Hg, and As. Remediation using conventional physical and chemical methods is uneconomical and generates waste chemicals in large quantities. This study focuses on the extraction and determination of heavy metals (Nickel, Copper and Cobalt) by chelating Schiff base ligands of the type [O,N,N,O] with these metal ions. Two Schiff base ligands [N,N’-ethylenebis(salicylimine)] (Salen) and ligand [1,3-bis(salicylideneamino)-2-propanol] (Sal-DAP) were synthesized and characterised using FTIR, 1H and 13C NMR spectrometry and GC-MS techniques. Electrochemical detection of heavy metal ions in this work was achieved via ligand-metal complexation via two approaches. The in-situ method in which the metal and ligands were added to the electrochemical cell and stirred to allow complexation to occur and monitored by square wave voltammetry. While the ex-situ approach involved modifying the electrode surface by depositing a thin film of Schiff base on the electrode surface and immersed into a heavy metal solution to allow the complexation. Three modified GCE were used viz. Salen coated GCE, reduced graphene oxide-Salen coated GCE and a nafion-Salen coated GCE. The two approaches used for the electrochemical detection were successful and effective. The ex-situ approach was selected for the modification of the electrode surface since it demonstrated a higher capacity for heavy metal ion extraction.