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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Legislação uso de água residuária: análises e propostas normativas. / Legislation use of wastewater: analysis and normative proposals.

MARTINS, Danilo Rodrigues. 29 May 2018 (has links)
Submitted by Johnny Rodrigues (johnnyrodrigues@ufcg.edu.br) on 2018-05-29T14:21:19Z No. of bitstreams: 1 DANILO RODRIGUES MARTINS - DISSERTAÇÃO PPGSA PROFISSIONAL 2018..pdf: 646787 bytes, checksum: 17b1a9fda99ec0a453a01f96019b7935 (MD5) / Made available in DSpace on 2018-05-29T14:21:19Z (GMT). No. of bitstreams: 1 DANILO RODRIGUES MARTINS - DISSERTAÇÃO PPGSA PROFISSIONAL 2018..pdf: 646787 bytes, checksum: 17b1a9fda99ec0a453a01f96019b7935 (MD5) Previous issue date: 2018 / A pesquisa tem por escopo trazer a discussão da necessidade de legislação específica para o reuso de águas residuárias que é uma prática de gestão sustentável dos recursos hídricos. Tendo como principal vantagem a redução da demanda por água potável, mitigando a pressão sobre os mananciais. Assim, tal redução decorre da aplicação das águas de reuso às finalidades que podem ser atendidas por águas com características menos restritivas do que às características exigidas para consumo humano, no viés da tecnologia agroindustrial e industrial. Devido aos riscos tanto à saúde pública quanto ao meio ambiente, decorrentes da prática do reuso de água residuária, o desenvolvimento do uso de tal tecnologia exigirá enérgica intervenção do Estado, na forma da lei, onde existe projeto, sem contudo finalizá-lo. O objetivo desta intervenção será maximizar os benefícios auferidos com a prática e reduzir os malefícios associados à sua gestão. De modo que a presente pesquisa tem como objetivo discutir a normatização da prática do reuso de água residuária no Brasil. As competências legislativas dos entes federativos e casos exitosos desta colmatação. Para tanto, procedeu-se à revisão bibliográfica do conceito de reuso de água, abordando seus tipos e aplicações, elencando, ainda, as finalidades de aplicação das águas de reuso. A revisão bibliográfica também teve como objetivo o levantamento do marco legal do reuso de água no Brasil. A partir do conceito de reuso de água pode ser estabelecida a relação entre a prática do reuso de água e os objetivos preconizados pela Política Nacional de Recursos Hídricos. Deste modo, se fará a pesquisa qualitativa com à utilização de dados no método hipotético-dedutivo observando as normas já existentes e à necessidade de legislação específica, analisando o projeto de Lei Federal sobre o tema e pontuando as especificações necessárias para minúcias, bem como fazendo uma pesquisa exploratório entrevistando atores que estão inseridos nesta necessidade de norma específica, dado o que se observa no entrave burocrático em razão da ausência de legislação específica. / The research aims to bring the discussion of the need for specific legislation for the reuse of wastewater, which is a practice of sustainable management of water resources. With the main advantage being the reduction of the demand for drinking water, mitigating the pressure on the sources. Thus, this reduction results from the application of the reuse water to the purposes that can be served by waters with characteristics less restrictive than the characteristics required for human consumption, in the bias of the agro-industrial technology, that is, use for the production of agricultural inputs. Due to the risks to both public health and the environment arising from the practice of reuse of wastewater, the development of the use of such technology will require vigorous State intervention, in the form of the law, where a project exists, without, however, finalizing it. The objective of this intervention will be to maximize the benefits of the practice and reduce the harm associated with its management. Therefore, the present research aims to discuss the standardization of the practice of wastewater reuse in Brazil. The legislative powers of federative entities and successful cases of this closure. In order to do so, a bibliographic review of the concept of water reuse was carried out, addressing its types and applications, also listing the purposes of reuse water application. The bibliographic review also had as objective the survey of the legal framework of the reuse of water in Brazil. From the concept of water reuse, the relationship between the practice of water reuse and the objectives advocated by the National Water Resources Policy can be established. In this way, qualitative research will be done using data in the hypothetical-deductive method, observing the existing norms and the need for specific legislation, analyzing the draft Federal Law on the subject and punctuating the necessary specifications for details, as well as making an exploratory research interviewing actors that are inserted in this need of specific norm, given what is observed in the bureaucratic obstacle due to the absence of specific legislation.
32

Evaluation of microbial health risks associated with the reuse of source-separated humna urine

Höglund, Caroline January 2001 (has links)
Human excreta contain plant nutrients and have the potentialto be used as a fertiliser in agriculture. Urine contributesthe major proportion of the nutrients (N, P and K) in domesticwastewater whereas faeces contribute a smaller amount andinvolves greater health risks if reused due to the possiblepresence of enteric pathogens. Human urine does not generallycontain pathogens that can be transmitted through theenvironment. Source-separation of urine and faeces is possible by usingurine-separating (or urine-diverting) toilets, available assimple dry toilets or porcelain flush toilets with dividedbowls. The risk for transmission of disease when handling andreusing the urine is largely dependent on thecross-contamination by faeces. In this research, the presenceof human faeces in urine samples was successfully determined byanalysing for faecal sterols. Cross-contamination was evidentin 22% of the samples from urine collection tanks, and in thesequantified to an average (± SD) of 9.1 ± 5.6 mgfaeces per litre urine. Testing for indicator bacteria wasshown to be an unsuitable method for determining faecalcontamination in human urine sinceE. colihad a rapid inactivation in the urine and faecalstreptococci were found to grow within the system. The fate of any enteric pathogens present in urine iscrucial for the risk for transmission of infectious diseases.Gram-negative bacteria (e.g.SalmonellaandE. coli) were rapidly inactivated (time for 90%reduction, T90&lt;5 days) in source-separated urine at itsnatural pH-value of 9. Gram-positive faecal streptococci weremore persistent with a T90of approximately 30 days. Clostridia sporenumbers were not reduced at all during 80 days. Similarly,rhesusrotavirus andSalmonella typhimuriumphage 28B were not inactivated inurine at low temperature (5°C), whereas at 20°C theirT90-values were 35 and 71 days, respectively.Cryptosporidiumoocysts were less persistent with a T90of 29 days at 4°C. Factors that affect thepersistence of microorganisms in source-separated human urineinclude temperature, pH, dilution and presence of ammonia. By using Quantitative Microbial Risk Assessment (QMRA), therisks for bacterial and protozoan infections related tohandling and reuse of urine were calculated to be&lt;10-3for all exposure routes independent of the urinestorage time and temperature evaluated. The risk for viralinfection was higher, calculated at 0.56 for accidentalingestion of 1 ml of unstored urine. If the urine was stored at20°C for 6 months the risk for viral infection was reducedto 5.4 × 10-4. By following recommendations for storage and reuse, whichare dependent on the type of crop to be fertilised, it ispossible to significantly decrease the risk for infections. Sofar, the level of risk that is acceptable is unknown. Theacceptable risk will be one of the main factors determining thefuture utilisation of source-separated human urine inagriculture. <b>Keywords:</b>urine-separation, urine, wastewater systems,wastewater reuse, recycling, enteric pathogens, faecal sterols,indicator bacteria, hygiene risks, microbial persistence,microbial risk assessment, QMRA, fertiliser, crop.
33

Evaluation of microbial health risks associated with the reuse of source-separated humna urine

Höglund, Caroline January 2001 (has links)
<p>Human excreta contain plant nutrients and have the potentialto be used as a fertiliser in agriculture. Urine contributesthe major proportion of the nutrients (N, P and K) in domesticwastewater whereas faeces contribute a smaller amount andinvolves greater health risks if reused due to the possiblepresence of enteric pathogens. Human urine does not generallycontain pathogens that can be transmitted through theenvironment.</p><p>Source-separation of urine and faeces is possible by usingurine-separating (or urine-diverting) toilets, available assimple dry toilets or porcelain flush toilets with dividedbowls. The risk for transmission of disease when handling andreusing the urine is largely dependent on thecross-contamination by faeces. In this research, the presenceof human faeces in urine samples was successfully determined byanalysing for faecal sterols. Cross-contamination was evidentin 22% of the samples from urine collection tanks, and in thesequantified to an average (± SD) of 9.1 ± 5.6 mgfaeces per litre urine. Testing for indicator bacteria wasshown to be an unsuitable method for determining faecalcontamination in human urine since<i>E. coli</i>had a rapid inactivation in the urine and faecalstreptococci were found to grow within the system.</p><p>The fate of any enteric pathogens present in urine iscrucial for the risk for transmission of infectious diseases.Gram-negative bacteria (e.g.<i>Salmonella</i>and<i>E. coli</i>) were rapidly inactivated (time for 90%reduction, T<sub>90</sub><5 days) in source-separated urine at itsnatural pH-value of 9. Gram-positive faecal streptococci weremore persistent with a T<sub>90</sub>of approximately 30 days. Clostridia sporenumbers were not reduced at all during 80 days. Similarly,<i>rhesus</i>rotavirus and<i>Salmonella typhimurium</i>phage 28B were not inactivated inurine at low temperature (5°C), whereas at 20°C theirT<sub>90</sub>-values were 35 and 71 days, respectively.<i>Cryptosporidium</i>oocysts were less persistent with a T<sub>90</sub>of 29 days at 4°C. Factors that affect thepersistence of microorganisms in source-separated human urineinclude temperature, pH, dilution and presence of ammonia.</p><p>By using Quantitative Microbial Risk Assessment (QMRA), therisks for bacterial and protozoan infections related tohandling and reuse of urine were calculated to be<10<sup>-3</sup>for all exposure routes independent of the urinestorage time and temperature evaluated. The risk for viralinfection was higher, calculated at 0.56 for accidentalingestion of 1 ml of unstored urine. If the urine was stored at20°C for 6 months the risk for viral infection was reducedto 5.4 × 10<sup>-4</sup>.</p><p>By following recommendations for storage and reuse, whichare dependent on the type of crop to be fertilised, it ispossible to significantly decrease the risk for infections. Sofar, the level of risk that is acceptable is unknown. Theacceptable risk will be one of the main factors determining thefuture utilisation of source-separated human urine inagriculture.</p><p><b>Keywords:</b>urine-separation, urine, wastewater systems,wastewater reuse, recycling, enteric pathogens, faecal sterols,indicator bacteria, hygiene risks, microbial persistence,microbial risk assessment, QMRA, fertiliser, crop.</p>
34

The challenge of implementing water harvesting and reuse in South Australian towns.

Rabone, Fiona Ann January 2007 (has links)
Water is precious, particularly in South Australia, the driest State in Australia, with over 80% of its land area receiving less than 250mm of rainfall per year. Security of water supply has always played a critical role in the economic and social development of South Australia, and will continue to do so while dependency on water from the River Murray is so high and there is competition over this from states and for different uses – municipal, irrigation, industry, and the environment. The drive towards sustainable development has evolved to attenuate overconsumption of the world’s natural resources of which water is a key element. Provision of reliable water supplies to regional South Australia has always presented challenges, given the vast distances involved and the limited number of natural water sources. Despite these, a majority of South Australians enjoy the benefit of a reliable and safe water supply, adequate waste disposal system, good community health and high standard of living. A challenge remains to determine the sustainability of current major water pipe transfer systems from remote resources to small communities. There may be scope for managing existing water supplies more effectively and further developing local water harvesting and reuse solutions to minimise the need for more significant infrastructure investment. This study investigates the challenges and opportunities for extending development of non-potable (secondary) water supply schemes in South Australian towns. These schemes will conserve the State’s freshwater resources. The primary focus of this study is harnessing stormwater runoff and treated effluent generated by normal township development to supplement higher quality public water for uses such as irrigation of public areas and sporting fields in country areas. Water harvesting and reuse is not likely to occur due to some technological breakthrough but through application of known technology and the adoption of water conscious ethics by society. However, it is a sensible reality for the South Australian climate, particularly when coupled with appropriate conservation and suitable landscaping practices. Thus, the major theme of this study is information sharing since if people are familiar with and understand the concepts then more communities may be encouraged to develop their resources. Water reuse has proven to be a beneficial strategy for addressing stormwater runoff and wastewater disposal problems and alleviating localised water supply problems for several South Australian towns and communities. The existing projects demonstrate both the strong community-based and innovative approach to water resources management in this state. They are inherently simple in form, and can often be assembled with readily available materials by people with a basic understanding of plumbing and construction skills (locally available). The potential for localised water harvesting and reuse in South Australian towns is generally limited to single purpose communal non-potable systems. Further, it is likely to only be sustainable in rural communities willing to make a commitment to its long term, proper operation and maintenance, or they could endanger public health. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1283773 / Thesis (M.Eng.Sc.) - University of Adelaide, School of Civil and Environmental Engineering, 2007
35

Réutilisation des eaux usées épurées par association de procédés biologiques et membranaires / Urban wastewater reuse by combination of biological and membrane processes

Jacob, Matthieu 19 April 2011 (has links)
Les procédés de réutilisation des eaux usées doivent être robustes, fiables et rentables pour que leur utilisation se démocratise et devienne complémentaire des traitements des eaux de surface. Le couplage d’un procédé biologique et de procédés membranaires représente une solution prometteuse pour répondre à ces challenges. Cette étude se focalise sur l’impact des conditions de fonctionnement du procédé secondaire (en particulier par bioréacteur à membrane BAM) sur le colmatage du procédé tertiaire de nanofiltration (NF) ou d’osmose inverse (OI) ainsi que sur le devenir des micropolluants et microorganismes tout au long de la chaine de traitement. Dans un premier temps, des expériences à court terme de filtration avec différentes membrane NF et d’OI ont été réalisées afin de caractériser les interactions entre effluents secondaires et membranes. Il a ainsi été observé de très fortes rétentions de tous les micropolluants ciblés par la Directive Cadre Européenne. En termes de colmatage, la chute de flux de l’OI, essentiellement liée pour ces essais de courte durée à une augmentation de pression osmotique puis à un dépôt de cristaux minéraux, peut être maîtrisée en contrôlant le pH et la concentration en carbonate et phosphate de l’effluent secondaire. Par ailleurs, des chutes de flux plus importantes sont observées lors des filtrations réalisées avec les membranes de NF qui sont plus sensibles au colmatage irréversible. Dans un second temps, l’optimisation de la filière de traitement des eaux usées urbaines couplant un bioréacteur à membranes à un procédé d’OI a été réalisée à partir d’une unité pilote fonctionnant en continu. La sélection de conditions opératoires adéquates a permis de faire fonctionner le procédé d’OI pendant plus de quatre mois sans qu’aucune maintenance ne soit réalisée. Une faible chute de flux de l’OI, linéaire sur toute la période de filtration, essentiellement dû à l’adsorption de molécules organiques à la surface de la membrane, a été observée. Sur l’ensemble de la période d’essais, la filière BAM/OI permet d’obtenir un abattement optimal en micropolluants présents. Lorsque des micropolluants sont injectés à des concentrations plus élevées (simulation d’une brusque dégradation de la qualité des eaux en entrée de filière) dans le bioréacteur, une chute de l’activité de la biomasse couplée à un relargage de produits microbiens solubles peut être observée. Néanmoins, ces pics de pollution n’ont eu aucun impact sur le colmatage de la membrane du BAM ni sur celle de l’OI. La filière BAM-OI permet donc de garantir un taux de rejet élevé et une productivité d’environ 15 L.h-1.m2 quelles que soient les fluctuations de la composition de l’eau usée urbaine à traiter. / In order to be competitive compare to surface water treatments, wastewater reuse needs robust, reliable and profitable combination of technologies. The combination of bioreactors and membrane processes seems to be a promising solution to these challenges. This study focus on the impact of the operating conditions of the secondary treatment (particularly the membrane bioreactor (MBR)) on the nanofiltration (NF) and reverse osmosis (RO) tertiary treatments as well as the fate of micropollutants and microorganisms along the treatment line. Firstly, short term filtration experiments with various NF and RO membranes were performed in order to characterize the interactions between secondary treatment effluents (STE) and membranes. High retentions of micropollutants listed by the European water framework directive were observed. During these short term experiments, RO flux decline is mainly due to an increase of osmotic pressure and then a precipitation of salts that can be solved by controlling the pH and thus the carbonate and phosphate concentration of the STE. In addition, higher flux declines are observed with NF because of a higher irreversible fouling behavior. Secondly, continuous long term tests were performed on a pilot unit combining a MBR and a RO processes. The appropriate selection of operating conditions allowed treating wastewater during more than four months without any maintenance. A linear low flux decline, mainly due to adsorption of organic molecules at the membrane surface was observed. During this filtration period, the MBR/RO process presented very high micropollutant retentions. When micropollutants are injected at higher concentration (simulation of sudden fluctuation of feed composition) into the MBR, a drop of biomass activity combined with soluble microbial products release can be observed. Nevertheless, these peaks of pollution did not cause any additional fouling of MBR as well as RO membranes. MBR/RO process is then a reliable technology that can guaranty high retention and productivity (around 15 L.h-1.m-2) whatever the fluctuations of the feed composition.
36

Tratamento terciario de esgoto sanitario para fins de reuso urbano / Tertiary wastewater treatment for urban reuse

Tosetto, Mariana de Salles 31 August 2005 (has links)
Orientadores: Ricardo de Lima Isaac, Regina Maura Bueno Franco / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo / Made available in DSpace on 2018-08-05T11:45:48Z (GMT). No. of bitstreams: 1 Tosetto_MarianadeSalles_M.pdf: 2211562 bytes, checksum: 608a86bf4dcf009813ef868c3b96d5c6 (MD5) Previous issue date: 2005 / Resumo: Este trabalho consistiu na análise da eficiência do tratamento terciário do efluente da Estação de Tratamento de Esgoto (ETE) Samambaia, no município de Campinas-SP, para fins de reuso em ambiente urbano. O sistema avaliado era composto das etapas de coagulação, pré-floculação em meio granular, filtração e desinfecção com radiação ultravioleta. O estudo experimental foi realizado em escala de bancada para otimização do processo de coagulação, e em escala piloto para avaliar as etapas de pré-floculação, filtração e desinfecção. Foram investigados, como coagulantes químicos, o sulfato férrico e o sulfato de alumínio, taxas de filtração de 120 e 300 m3/m2.dia, e dose de radiação UV de, aproximadamente, 95 mWs/cm2. O efluente terciário produzido na instalação piloto não foi considerado seguro sob o aspecto de saúde pública para aplicação em reuso urbano, como irrigação de parques e jardins, limpeza urbana, lavagem de veículos, combate a incêndio, entre outros, pois não atendeu as recomendações da Organização Mundial de Saúde ¿ OMS quanto à concentração de ovos de helmintos, e apresentou cistos de Giardia spp. ainda em concentrações elevadas, embora nenhuma das recomendações encontradas na literatura contemple limites para estes últimos. Os parâmetros turbidez, DBO, sólidos em suspensão, Coliformes Totais e E. coli atenderam as metas e padrões recomendados na literatura para reuso urbano / Abstract: This work consisted of efficiency analysis of tertiary treatment of effluent from a Wastewater Treatment Plant (WWTP Samambaia) that is located at the city of Campinas (São Paulo State, Brazil), for urban reuse. The system consisted of a physico-chemical treatment composed of coagulation, granular upflow flocculation, direct downflow filtration and ultraviolet disinfection. The experimental work was carried out using bench-scale tests to optimize chemical coagulation, and in a pilot installation to evaluate the flocculation, filtration and disinfection steps. Aluminum sulfate and ferric sulfate were evaluated as coagulants. Filtration rates of 120 and 300 m/day and UV doses of 95 mWs/cm2 were applied. The tertiary effluent obtained at the pilot plant was not considered safe, under the public health point of view, for urban reuse, like gardens and parks irrigation, urban cleaning, car-washing, fire protection and others, because the helminth eggs concentration, that did not comply to World Health Organization-WHO recommendation, and the high level of Giardia spp. cysts concentration detected at the tertiary-treated effluent, although the quality requirements for urban reuse do not limit this concentration. The turbidity, BOD, suspended solids and coliforms parameters were according to literature recommendation for urban reuse / Mestrado / Saneamento e Ambiente / Mestre em Engenharia Civil
37

AvaliaÃÃo dos Riscos Ambientais e EcotoxicolÃgicos do ReÃso de Ãguas ResiduÃrias em Piscicultura / Evaluation of Environmental and Ecotoxicological Risks of Wastewater Reuse for Fish Farming

Soraia Tavares de Souza Gradvohl 14 August 2006 (has links)
FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico / A preocupaÃÃo com relaÃÃo à qualidade e à quantidade de Ãgua potÃvel tem incentivado o reÃso de Ãgua como uma das alternativas para enfrentar este problema. O reÃso tornou-se, portanto, um importante instrumento de gestÃo ambiental, visando à liberaÃÃo da Ãgua de melhor qualidade para fins mais nobres. O reÃso com aplicaÃÃo na piscicultura constitui fonte alternativa de produÃÃo de proteÃna a baixo custo, alÃm de funcionar como uma forma de reciclagem de nutrientes. Mas, a sustentabilidade desta atividade està diretamente relacionada à qualidade do efluente tratado e seus efeitos sobre a qualidade da Ãgua nos tanques de peixes. Outro fato notÃrio à a crescente preocupaÃÃo com os riscos potenciais inerentes a esta atividade. Diante deste cenÃrio, surgiu a necessidade de realizar um estudo mais profundo dos riscos inerentes ao reÃso de Ãguas residuÃrias, tanto numa abordagem ambiental, como num ponto de vista ecotoxicolÃgico. Para isso, foram realizados testes de toxicidade aguda, de curta duraÃÃo, para avaliaÃÃo da toxicidade dos efluentes tratado e bruto provenientes de uma EstaÃÃo de Tratamento de Esgoto a nÃvel terciÃrio, composto por um sistema de lagoas de estabilizaÃÃo, tendo como organismos-teste peixes de Ãgua doce da espÃcie Oreochromis niloticus (tilÃpia do Nilo). Os testes objetivaram determinar o Ãndice de toxicidade aguda (LC50). O efluente tratado foi utilizado em duas etapas distintas, com peixes com idade superior a 60 dias e alevinos com tempo de vida inferior a 15 dias. Em ambos, nÃo foi observada mortalidade de nenhum organismo. No caso do esgoto bruto, o ensaio foi realizado com e sem aeraÃÃo, sendo obtido para o esgoto bruto sem aeraÃÃo os Ãndices de LC50-24h de 68,0% e LC50-96h de 35,4%. Jà com a aeraÃÃo mecÃnica aplicada Ãs duas diluiÃÃes de 50 e 100% de esgoto bruto, os LC50âs encontrados foram de 44,5% (24 h), 41,0% (48 h) e 36,7% (96 h). O ensaio foi tambÃm realizado para avaliaÃÃo do nÃvel de toxicidade da amÃnia, tendo em vista que a mesma tem sido considerada por vÃrios pesquisadores um produto tÃxico Ãs algas, ao zooplÃncton e aos peixes. Para estes ensaios foram determinados os LC50âs de 2,01 mg/L NH3-N (2 h), 1,97 mg/L NH3-N (4 h) e 1,66 mg/L NH3-N (atà 96 h). AlÃm disso, foi realizado um ensaio com nitrogÃnio amoniacal variando-se o pH para originar trÃs meios distintos â Ãcido, neutro e bÃsico â devido a influÃncia deste no Ãndice de toxicidade calculado. Os LC50âs encontrados neste caso foram: 8,70 mg/L para o tempo de 2 a 4 horas e 6,45 mg/L para 24, 48 e 96 horas para o meio Ãcido; 8,70 mg/L para 2 horas e 6,45 mg/L para 4, 24, 48 e 96 horas para o meio neutro; e, 1,96 mg/L de 2 horas em diante para o meio bÃsico. Por fim, foi utilizada uma metodologia de anÃlise de riscos buscando-se realizar um estudo dos efeitos potenciais à saÃde humana e ao meio ambiente, e ainda propondo-se medidas para tentar minimizar os possÃveis impactos adversos.
38

Transport of Enterococcus faecalis JH2-2 through sandy sediments: A combined experimental and modelling approach

Chandrasekar, Aparna 13 October 2022 (has links)
The agricultural sector is one of the largest consumers of fresh water. With the ever-increasing problem of water scarcity, urbanization, over-population, and climate change, fresh water resources used by agriculture could be put to better use by redirecting it for drinking water purposes. In this context, many countries reuse treated urban waste water for irrigation, to overcome this problem. While this is a sustainable practice, the reuse of urban wastewater could facilitate the spread of pathogenic bacteria (or antibiotic resistant bacteria) in the subsoil region and consequently the groundwater. Since groundwater is one of the main sources of drinking water, the contaminants could pose a risk to human health. Furthermore, obtaining scientific data for emerging contaminants during water reuse is the need of the hour. The objective of this work is to build a mechanistic model that can aid in the development of large-scale risk assessment models; thus facilitating the setup of water reuse regulations for the relevant pathogenic organisms. In the present study, process based models were developed and evaluated using lab scale results. Then, the relative time scales of the processes are compared, and the relative importance of the various process studies are assessed. When assessing time scales of the processes, it is kept in mind that processes with relatively fast time scales can be approximated using equilibrium models, relatively slow processes can be neglected, and only the rate limiting processes can neither be neglected or further simplified in further model development. Therefore, an idea of the rate limiting processes assessed in lab scale can serve as important tools facilitating model simplification when evaluating larger scale models. A combined experimental and modelling approach has been used to study relevant transport and reactive processes during bacteria transport through sandy sediments. The mechanistic model contained transport processes which were implemented using the advective dispersive equation. An additional straining process was added using non-linear rate law. The biological processes of decay, respiration, attachment, and growth were expressed using linear rate laws. This mechanistic model was verified using data from fully water saturated, sediment packed lab-scale column experiments. Continuous injection of tracer, microspheres, and Enterococci (in water environments with and without dissolved oxygen and nutrients) was performed. The experiment was verified for three flow velocities (0.13, 0.08 and 0.02 cm/min), and the parameter values were compared for these flow velocities using dimensionless numbers. The linear rate coefficients were converted to a dimensionless form (Peclet and Damkoehler numbers respectively) to facilitate the comparison of processes across the various flow velocities. The results indicate that the processes of attachment and growth are flow dependent. Furthermore, in the presence of dissolved oxygen, attachment of bacteria to sediment was the most influential process. Sensitivity analysis showed that the parameters representing growth and respiration were influential, and care must be taken when using the results for field-scale experiments or models. These processes and parameters add new knowledge on the impact of urban wastewater reuse on the spread of pathogenic bacteria (especially resilient species like Enterococci), and emphasizes the importance of research in this area. Future work could focus on obtaining data from culture independent methods and extension of the model framework, and include (where necessary) non-linear rate laws. This will provide a critical pathway to developing a decision support framework for use by regulatory frameworks, policy makers, stakeholders, local and global environmental agencies, World Health Organization, or the United Nations.:List of Figures vii List of Tables xi List of Abbreviations xiii List of Symbols xv Summary xvii Zussamenfassung xix 1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.1 Broad Scope. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.2 Hypotheses and Research objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 1.3 Outline of the work . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 2 Concepts, terminologies, and methodology 7 2.1 Concepts and terminologies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 2.1.1 Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 2.1.2 The vadose zone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 2.1.3 Porosity and pore models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 2.1.4 Darcy’s law . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 2.2 Bacteria strain used and Processes Studied . . . . . . . . . . . . . . . . . . . . . . . . . 14 2.2.1 Enterococcus faecalis JH2-2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 2.2.2 Advection and Dispersion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 2.2.3 Straining . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 2.2.4 Microbial Decay and Respiration . . . . . . . . . . . . . . . . . . . . . . . . . . 16 2.2.5 Microbial Attachment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 2.2.6 Microbial Growth. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 2.2.7 Dimensionless numbers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 2.3 Experimental design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 2.4 Model setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 3 Reactive-transport modelling of Enterococcus faecalis JH2-2 passage through water saturated sediment columns. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 3.1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 3.2 Materials and methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 3.2.1 Experimental study. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 3.2.2 Modeling and data analysis procedure. . . . . . . . . . . . . . . . . . . . . . . . 40 3.3 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 3.3.1 Determination of hydraulic and non-reactive transport parameters (experiments E1 and E2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 3.3.2 Determination of parameters related to the bacteria transport (E3 series) . . . 45 3.4 Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 3.4.1 Physical processes (E1 and E2) . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 3.4.2 Biological Processes (E3 series) . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 3.5 Conclusions and Outlook. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56 3.6 Supplementary material . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 4 Determining the impact of flow velocities on reactive processes associated with Enterococcus faecalis JH2-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 4.1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67 4.2 Materials and methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68 4.2.1 Experimental setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68 4.2.2 Model Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71 4.3 Results and Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74 4.3.1 Tracer and microsphere experiments. . . . . . . . . . . . . . . . . . . . . . . . . 74 4.3.2 Bacteria experiments - comparison of processes. . . . . . . . . . . . . . . . . . . 75 4.4 Conclusions and Future work . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79 4.5 Supplementary material 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81 4.6 Supplementary Material 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84 5 Synthesis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87 5.1 Discussion and conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87 5.2 Critical review, pathways towards future work . . . . . . . . . . . . . . . . . . . . . . . 91 Bibliography. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93 Note on the commencement of the doctoral procedure. . . . . . . . . . . . . . . . . . . . 107 Übereinstimmungserklärung. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109 List of Publications and conference presentations. . . . . . . . . . . . . . . . . . . . . . . . 111 Acknowledgements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115 / Der Agrarsektor ist einer der größten Verbraucher von Süßwasser. Angesichts der zunehmenden Wasserknappheit, der Verstädterung, der Überbevölkerung und des Klimawandels könnten die von der Landwirtschaft genutzten Süßwasserressourcen besser genutzt werden, indem sie für Trinkwasserzwecke umgewidmet werden. In diesem Zusammenhang verwenden viele Länder aufbereitetes kommunales Abwasser für die Bewässerung, um dieses Problem zu lösen. Dies ist zwar eine nachhaltige Praxis, aber die Wiederverwendung von kommunalem Abwasser könnte die Ausbreitung pathogener Bakterien (oder antibiotikaresistenter Bakterien) im Untergrund und damit im Grundwasser fördern. Da das Grundwasser eine der Hauptquellen für Trinkwasser ist, könnten diese Schadstoffe eine Gefahr für die menschliche Gesundheit darstellen. Darüber hinaus ist es ein Gebot der Stunde, wissenschaftliche Daten über neu auftretende Verunreinigungen bei der Wasserwiederverwendung zu gewinnen. Ziel dieser Arbeit ist es, ein mechanistisches Modell zu erstellen, das bei der Entwicklung groß angelegter Risikobewertungsmodelle behilflich sein kann und somit die Aufstellung von Vorschriften für die Wiederverwendung von Wasser für die relevanten pathogenen Organismen erleichtert. In der vorliegenden Studie wurden prozessbasierte Modelle entwickelt und anhand von Ergebnissen im Labormaßstab bewertet. Anschließend werden die relativen Zeitskalen der Prozesse verglichen und die relative Bedeutung der verschiedenen Prozessstudien bewertet. Bei der Bewertung der Zeitskalen der Prozesse wird berücksichtigt, dass Prozesse mit relativ schnellen Zeitskalen durch Gleichgewichtsmodelle angenähert werden können, relativ langsame Prozesse können vernachlässigt werden, und nur die ratenbegrenzenden Prozesse dürfen in der weiteren Modellentwicklung weder vernachlässigt noch vereinfacht werden. Daher kann eine Vorstellung von den ratenbegrenzenden Prozessen, die im Labormaßstab bewertet werden, als wichtiges Instrument zur Vereinfachung des Modells bei der Bewertung von Modellen in größerem Maßstab dienen. Ein kombinierter experimenteller und modellierender Ansatz wurde verwendet, um relevante Transport- und reaktive Prozesse während des Bakterientransports durch sandige Sedimente zu untersuchen. Das mechanistische Modell enthielt Transportprozesse, die mit Hilfe der Advektions-Dispersions-Gleichung implementiert wurden. Ein zusätzlicher Filtrationsprozess ('straining') wurde mit Hilfe nichtlinearer Ratengesetze hinzugefügt. Die biologischen Prozesse des Zerfalls, der Atmung, der Anhaftung und des Wachstums wurden durch lineare Ratengesetze ausgedrückt. Dieses mechanistische Modell wurde anhand von Daten aus vollständig wassergesättigten, sedimentgefüllten Säulenexperimenten im Labormaßstab verifiziert. Kontinuierliche Injektion von Tracer, Mikrosphären und Enterokokken (in Wasserumgebungen mit und ohne gelösten Sauerstoff und Nährstoffe) wurde durchgeführt. Das Experiment wurde für drei Strömungsgeschwindigkeiten (0,13, 0,08 und 0,02 cm/min) verifiziert, und die Parameterwerte wurden für diese Strömungsgeschwindigkeiten anhand dimensionsloser Zahlen verglichen. Die linearen Ratengesetze wurden in eine dimensionslose Form umgewandelt (Peclet- bzw. Damköhler-Zahlen), um den Vergleich der Prozesse bei den verschiedenen Strömungsgeschwindigkeiten zu erleichtern. Die Konzentrationen wurden in regelmäßigen Abständen sowohl am Einlass als auch am Auslass der Kolonnen gemessen. Die überprüften Prozesse waren Advektion, Dispersion, Filtration, Zerfall, Atmung, Wachstum und Anhaftung. Der Versuch wurde für drei Strömungsgeschwindigkeiten (0,13, 0,08 und 0,02 cm/min) wiederholt, und die verifizierten Parameterwerte wurden für diese Strömungsgeschwindigkeiten verglichen. Die Ergebnisse zeigen, dass die Prozesse der Anhaftung und des Wachstums strömungsabhängig sind. Darüber hinaus war bei Vorhandensein von gelöstem Sauerstoff die Anhaftung der Bakterien an das Sediment der einflussreichste Prozess. Die Sensitivitätsanalyse zeigte, dass die Parameter, die das Wachstum und die Atmung repräsentieren, einflussreich sind, so dass bei der Verwendung der Ergebnisse für Experimente oder Modelle im Feldmaßstab Vorsicht geboten ist. Diese Prozesse und Parameter liefern neue Erkenntnisse über die Auswirkungen der Wiederverwendung von kommunalem Abwasser auf die Ausbreitung pathogener Bakterien (insbesondere widerstandsfähiger Arten wie Enterokokken) und unterstreichen die Bedeutung der Forschung in diesem Bereich. Zukünftige Arbeiten könnten sich auf die Gewinnung von Daten aus kulturunabhängigen Methoden und die Erweiterung des Modellrahmens konzentrieren und (wo nötig) nichtlineare Parameter einbeziehen. Dies wird einen entscheidenden Weg zur Entwicklung eines Rahmens für die Entscheidungsfindung darstellen, der von Regulierungsbehörden, politischen Entscheidungsträgern, Interessengruppen sowie lokalen und globalen Umweltbehörden, der Weltgesundheitsorganisation oder den Vereinten Nationen genutzt werden kann.:List of Figures vii List of Tables xi List of Abbreviations xiii List of Symbols xv Summary xvii Zussamenfassung xix 1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.1 Broad Scope. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.2 Hypotheses and Research objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 1.3 Outline of the work . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 2 Concepts, terminologies, and methodology 7 2.1 Concepts and terminologies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 2.1.1 Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 2.1.2 The vadose zone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 2.1.3 Porosity and pore models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 2.1.4 Darcy’s law . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 2.2 Bacteria strain used and Processes Studied . . . . . . . . . . . . . . . . . . . . . . . . . 14 2.2.1 Enterococcus faecalis JH2-2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 2.2.2 Advection and Dispersion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 2.2.3 Straining . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 2.2.4 Microbial Decay and Respiration . . . . . . . . . . . . . . . . . . . . . . . . . . 16 2.2.5 Microbial Attachment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 2.2.6 Microbial Growth. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 2.2.7 Dimensionless numbers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 2.3 Experimental design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 2.4 Model setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 3 Reactive-transport modelling of Enterococcus faecalis JH2-2 passage through water saturated sediment columns. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 3.1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 3.2 Materials and methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 3.2.1 Experimental study. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 3.2.2 Modeling and data analysis procedure. . . . . . . . . . . . . . . . . . . . . . . . 40 3.3 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 3.3.1 Determination of hydraulic and non-reactive transport parameters (experiments E1 and E2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 3.3.2 Determination of parameters related to the bacteria transport (E3 series) . . . 45 3.4 Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 3.4.1 Physical processes (E1 and E2) . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 3.4.2 Biological Processes (E3 series) . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 3.5 Conclusions and Outlook. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56 3.6 Supplementary material . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 4 Determining the impact of flow velocities on reactive processes associated with Enterococcus faecalis JH2-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 4.1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67 4.2 Materials and methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68 4.2.1 Experimental setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68 4.2.2 Model Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71 4.3 Results and Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74 4.3.1 Tracer and microsphere experiments. . . . . . . . . . . . . . . . . . . . . . . . . 74 4.3.2 Bacteria experiments - comparison of processes. . . . . . . . . . . . . . . . . . . 75 4.4 Conclusions and Future work . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79 4.5 Supplementary material 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81 4.6 Supplementary Material 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84 5 Synthesis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87 5.1 Discussion and conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87 5.2 Critical review, pathways towards future work . . . . . . . . . . . . . . . . . . . . . . . 91 Bibliography. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93 Note on the commencement of the doctoral procedure. . . . . . . . . . . . . . . . . . . . 107 Übereinstimmungserklärung. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109 List of Publications and conference presentations. . . . . . . . . . . . . . . . . . . . . . . . 111 Acknowledgements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115
39

WATER PROVISION FOR SMALL, ARID ISLANDS: FINDING SOLUTIONS FOR THE ISLANDS OF THE SOUTH AEGEAN SEA

VAMVAKIDOU, MARIA 01 July 2004 (has links)
No description available.
40

Accumulation and colloidal mobilization of trace heavy metals in soil irrigated with treated wastewater / Immobilisation et transport colloidal des métaux lourds en concentrations traces dans les sols irrigués par des effluents urbains traités

Pontoni, Ludovico 15 December 2016 (has links)
La réutilisation des eaux usées traitées pour l’irrigation est globalement acceptée et pratiquée pour faire face à la pénurie d'eau et économiser les ressources de haute qualité. Bien que cette pratique présente des avantages indéniables et contribue à un usage plus durable de l'eau douce, elle n’est pas exempt de problèmes liés à l'impact potentiel sur la qualité des sols récepteurs et sur les cultures de micropolluants contenus dans l'eau réutilisée. Parmi ces polluants, les métaux lourds (ML) en concentrations traces jouent un rôle primordial en raison de leur présence systématique dans l'eau utilisée et de leur persistance une fois libéré dans l'environnement. Le devenir des ML dans les sols peut difficilement être prédit parce que les mécanismes de mobilité à travers les sols sont extrêmement variés et liés à des phénomènes simultanés et très complexes impliquant différents équilibres chimiques. Les ML, comme beaucoup d'autres contaminants, ne sont pas seulement partagé entre la phase immobile (le sol) et les phases mobiles présentes dans l'eau. En effet, les colloïdes et les nanoparticules agissent comme une troisième phase mobile, avec leurs propres propriétés rhéologiques et des vitesses de migrations qui leur sont propres. Ce dernier aspect a été l'un des principaux objectifs d’étude de la thèse. Plusieurs essais expérimentaux ont été menés en irriguant un sol standard selon l'Organisation de coopération et de développement économiques (OCDE) avec une eau usés traités réel et / ou synthétiques, contenant des ML en concentrations traces. Pour chaque test, un sol spécifique (avec différentes teneurs en matière organique) et des eaux usées traitées de composition différente (avec différentes concentrations en métaux traces, de salinité, de la teneur en matière organique pour les eaux usées synthétiques, ou des eaux usées traitées réelles) ont été choisi afin d'évaluer les effets des conditions différentes sur le devenir global des ML. L'augmentation de la matière organique du sol de 2,5 à 10% a linéairement amélioré la mobilité des Cd, Cu et Ni avec une augmentation de la mobilité maximum de 35,6, 43,7 et 49,19% pour le Cd, Cu et Ni, respectivement. Pour la plupart des expériences, les ML ont été capturés dans la couche superficielle du sol (0,5 à 1 cm). Néanmoins, des pics de contamination ont été détectés à des profondeurs différentes dans les couches plus profondes du sol. L’étude de la composition des lixiviats montre des variations de concentrations fonction du métal étudié et des caractéristiques du sol et des eaux usées. Des pics de métaux dans le lixiviat sont apparus en même temps que la libération de la matière et / ou la libération de silicates organiques, ce qui démontre l'implication significative des colloïdes dans le transport des métaux. La concentration en sodium (20 mM) a été démontrée un impact fort sur la réduction de la mobilisation colloïdale et que plus de 95% du métal apporté a été détecté dans la couche superficielle du sol en dépit de sa teneur en matière organique. La salinité affiche donc des effets significatifs. L'irrigation avec des eaux usées traitées présentant une très haute teneur en Ca et Mg (111 et 134 mg / L, respectivement) a abouti à la libération moyenne plus élevée de silicium à partir de la matrice inorganique du sol (8,2 mg / L) par rapport à la faible salinité des eaux usées artificielle (1,9 mg / L). Par conséquent, la mobilisation ultérieure de Cd, Cu, Ni et Zn a été observée lorsque le sol a été irrigué avec des eaux usées traitées réelles. Une caractérisation spectroscopique avancée des lixiviats a été réalisée pour identifier les agrégats colloïdaux libérés par le sol dans le but d’en déterminer leur nature, leurs propriétés chimiques et leur état d'agrégation / Reuse of treated wastewater for agricultural purposes is worldwide accepted and practiced to face water scarcity and save high quality resources. Although such practice has undoubtable advantages and is certainly more sustainable respect to the use of fresh water, it is not exempt from severe concerns related to the potential impact on the receiving soil and on the crops of potentially harmful pollutants contained in the reused water at trace levels. Among these pollutants, trace heavy metals (HMs) play a primary role due to their spread presence in the used water and to their persistence once released in the environment. The fate of HMs in the soils can be hardly predicted as mechanisms of mobility through soils are extremely diverse and related to highly complex simultaneous phenomena and chemical equilibria. HMs, in fact, as many other contaminants, are not only partitioned between the solid immobile and the water mobile phases. Indeed, colloids and nanoparticles act as a third mobile phase, with their own rheological properties and velocity. This latter aspect has been one of the main focus of the thesis. In details the thesis describes the results of several experiments conducted irrigating the OECD standard soil with real and/or synthetic wastewater, containing HMs in trace. For each test a specific soil (e.g. varying the organic matter content) and wastewater composition (e.g. varying the metals concentration, the salinity, the organic matter content, or testing real treated wastewaters) has been chosen in order to evaluate the effects of different conditions on the overall HMs fate. The increase of soil organic matter from 2,5 to 10% linearly enhanced the mobility of Cd, Cu and Ni up to a maximum mobility increase of 35.6, 43.7 and 49.19 % for Cd, Cu and Ni, respectively. In most experiments metals accumulated in the top soil layer (0.5 - 1 cm). Nevertheless peaks of contamination were detected at different depths in the soil deeper layers and at different leaching time in the leachates depending on the metal and on the soil and wastewater characteristics. Peaks of metals in the leachate appeared simultaneously with release of organic matter and/or release of silicates, demonstrating outstanding involvement of colloids in metals transport. Sodium concentration (20mM) decidedly reduced colloidal mobilization whereas more than 95 % of the influent metal was detected in the top layer despite the soil organic matter content. Salinity displayed different effects. The irrigation with real treated wastewater with quite high content of Ca and Mg (111 and 134 mg/L, respectively) resulted in higher average release of silicon from the soil inorganic matrix (8.2 mg/L) compared to the low salinity artificial wastewater (1.9 mg/L). Consequently higher mobilization of Cd, Cu, Ni and Zn was observed when the soil was irrigated with real treated wastewater. An advanced spectroscopical characterization of the leachates was performed to identify such colloidal aggregates. The observation of 3D excitation-emission matrix demonstrated in all the leachates samples the presence of fulvic (230-450 nm ex-em fluorescence area) and humic (330-445 nm ex-em) substances. In this context, a novel analytical method was developed to quantify phenolic substances in soil matrices allowing the monitoring of humic matter migration in soil profiles. The novel method was more accurate and more precise respect to the traditional one, allowing to obtain higher recovery of total phenols in peat soil (15.5 % increase) with a decrease of the coefficient of variation (30.1% decrease). Organic water soluble colloids were extracted from the peat used to prepare the OECD standard soil and characterized. Results of size exclusion chromatography highlighted the supramolecular structure of the extracted organic matter. Such structure was further confirmed through fluorescence and 1H-NMR spectroscopy

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