Thèse doctorat : Génie Civil Urbain : Villeurbanne, INSA : 2006. / Titre provenant de l'écran-titre. Bibliogr. p. 166-178.

Thèse doctorat : Génie Civil : Villeurbanne, INSA : 2006. / Titre provenant de l'écran-titre. Bibliogr. p. 185-196.

Sustainable Built Environments Senior Capstone Project / Across the world, populations continue to grow while water supplies stay fixed. In the American Southwest, water supplies are at an all time low, yet warm, favorable conditions continue to lure residents to the area. With some of the country’s lowest fresh water reserves, it is imperative that changes are made to water usage trends and associated energy inefficiencies. An analysis of water usage in Tucson was conducted to evaluate potential solutions for reducing consumption and to correspondingly shrink energy usage. Case studies were investigated, census numbers were used to roughly calculate statistics, existing knowledge on water conservation techniques were researched, and alternative water filtration as well as distribution systems were scrutinized for their viability amongst current infrastructure. The potential to reduce water usage is greatest with the largest user of water in Tucson, the single-family residence. On average the single-family residence is capable of effectively saving nearly 25,000 gallons of water per year with efficient fixtures, another 25,000 gallons per year by reducing outdoor water use by half, and another 10,625 gallons by utilizing rainwater harvesting. Combine those savings and multiply them by the 225,000-240,000 single-family residents estimated to be in Tucson and the savings reach more than five billion gallons a year, effectively almost cutting water consumption in Tucson by a fifth. Further, to keep remaining usage impacts negligible, implementation of an indirect or direct potable water reuse system could satisfy populations for decades by reusing water that would normally be discarded as effluent. Water consumption must be curved so that it can satisfy a growing population’s needs. Amongst residents of Tucson, single-family residences have the greatest potential to reduce water and associated energy needs. Through conservation techniques, water harvesting, reducing outdoor water usage, and potable reuse, limited water supplies can satisfy future generations to come.

El presente trabajo de investigación planteó un estudio que se enfocó en la problemática de las comunidades de nuestro país en relación al consumo y calidad del agua, siendo éste uno de los factores para afirmar que existe pobreza multidimensional, reflejando con mayor incidencia en zonas rural marginales, un claro ejemplo se encuentra en el caserío Puente Tulipe, donde el abastecimiento de agua para los pobladores es por fuentes poco seguras al igual que su forma de manejo y consumo, planteándose la siguiente pregunta de investigación ¿cómo mejorar la gestión del conocimiento de los pobladores frente al consumo y calidad del agua?, cuyo objetivo general es gestionar el conocimiento de los pobladores frente al consumo y calidad del agua. Fue una investigación cualitativa con abordaje metodológico de investigación acción participación y se ejecutó en el caserío Puente Tulipa, Pátapo. El abordaje teórico se basó en el modelo de promoción de salud de Nola J. Pender. Los sujetos de estudio fueron 20 pobladores del caserío Puente Tulipe, quienes habitan el Km32 del canal Taymi. Para recolectar la información se utilizó la entrevista semiestructurada con la técnica de grupos focales. Se respetaron los criterios éticos de Sgreccia y los criterios de rigor científico. Se realizó un análisis temático, obteniendo como resultados: conocimiento gestionado en los actores sociales frente al consumo y gestión de la calidad del agua y desarrollo de estilos de vida saludable en la comunidad respecto a calidad, consumo de agua y la repercusión en su salud.

Access to potable water has been on the forefront of the international agenda for almost three decades. The international community has been working together in developing potable water management programs and improving potable water access. This thesis examines how the nature of rural communities influences water usage and rural potable water projects in Nicaragua. Factors such as proximity to urban environments and exposure to nongovernmental organizations are demonstrated to play a role in shaping community expectations and satisfaction with potable water projects. The author proposes approaches for addressing urban influence focused on improving flexibility of project consultation processes, strengthening project monitoring, and enhancing the level of community knowledge with respect to available potable water systems. The author briefly explores how this case study is transferrable to other communities in developing countries.

Introduction: L'Arsenic (As) est un cancérigène reconnu et est suspecté pour ses propriétés de perturbateur endocrinien. En Abitibi-Témiscamingue (A-T), plusieurs puits privés contiennent des concentrations en As inorganique (iAs) qui dépassent la concentration maximale acceptable (CMA) de 10 [mu]g/L recommandée par Santé Canada ce qui pourrait avoir des conséquences sur la santé. Objectifs: 1- Vérifier la corrélation entre le niveau de contamination des puits en As et les indicateurs de fonction thyroïdienne en circulation dans le sang; 2- Mesurer la relation entre le niveau de contamination des puits en As et la prévalence du diabète. Méthode: Une étude descriptive transversale a été effectuée chez les propriétaires de puits privés de huit municipalités de l'A-T. Pour être éligible, les personnes intéressées devaient boire ou utiliser l'eau non traitée de leur puits pour la préparation de breuvages ou la cuisson d'aliments depuis au moins un mois, être âgées de 7 ans et plus et ne pas être exposées à l'iAs au travail. La dose externe a été estimée à l'aide de la concentration d'iAs dans l'eau du puits. La dose interne a été estimée par des mesures d'As urinaire non alimentaire (somme d'AMMA, ADMA, AslIl, et AsV) corrigées pour la créatinine et d'As total dans les ongles d'orteils. Des prélèvements sanguins ont servi à l'analyse de la fonction thyroïdienne (TSH, T3L et T4L), des anticorps anti-thyroïdiens (anti-TPO et anti-TG) et de l' HbA1c. Résultats: La moyenne géométrique de la concentration d'iAs des puits à l'étude (n=153) etait de 14,2 [mu]g/L. Après exclusion des participants traités pour hypothyroïdie et contrôle des facteurs de confusion (âge, sexe, anticorps anti-thyroïdiens, sources d'As alimentaire, tabagisme et histoire familiale de troubles thyroïdiens), une analyse de régression linéaire a indiqué que l'iAs dans l'eau du puits était positivement associé à la TSH (p=0,001) et négativement associé à la T3L (p<0,001) et à la T4L (p=0,003) chez les adultes alors que seule la TSH était associée à cet indicateur d'exposition chez les enfants (p=0,004). Une analyse de régression logistique effectuée apres contrôle des facteurs de confusion (âge, sexe, sources d'As alimentaire, histoire familiale de diabète, IMC) a aussi révélé que la présence de l'un ou l'autre des indicateurs de diabète (HbA1c>6,0%, présence d'antécédent personnel de diabète, consommation d'hypoglycémiants oraux ou prise d'insuline) était associé à l'iAs dans l'eau du puits (p=0,009) et à l'As unguéal (p=0,019) chez les adultes. Un adulte diabétique avait 2,84 fois plus de chance d'être exposé à plus de 33 [mu]g/L d'iAs dans l'eau du puits qu'un non-diabétique (IC95%: L29-6,24; p=0,010). Conclusion: Cette étude supporte la possibilité que l'iAs à faible dose entraîne des effets endocriniens.

Three iron oxide materials have been studied for uptake of three anions (arsenate, phosphate and fluoride) and a cation (cadmium) from aqueous solutions. Two of the materials were produced using original procedures developed at Loughborough University. The former material was conditioned by a controlled freeze-thaw procedure to enhance granularity and the latter was air-dried at room temperature. Their capacities were compared with a commercially available material supplied by GEH Wasserchemle, Germany. Pore size distributions and specific surface area values were determined by N2 analysis at 77 K. All samples possessed a reasonable specific surface area, in the range 200-300 m2/g and were mesoporous. Samples produced at Loughborough University also contained some macropores, evidence of a more amorphous structure or lack of pH control during production. X-ray diffraction indicated that all samples had some b-FeOOH present and that the chloride content and production pH affected the material crystallinity. Crystallinity increased with increasing chloride content and a higher production pH resulted in the presence of more than one phase. Chemical characterisation was also completed on all three samples. The point of zero net proton charge and isoelectric point for each material was obtained by potentiometric batch titrations and zeta potential measurements respectively. The difference in these values increased with a higher chloride content and all samples studied possessed a positive surface at low pH and negative surface at high pH. These parameters were not greatly affected by the background electrolyte concentration, implying that the background electrolyte is not specifically adsorbed. However, arsenate and phosphate appeared to be specifically adsorbed as the isoelectric point decreased. The uptake capacities for arsenate, phosphate. fluoride and cadmium of all three samples were obtained by measuring batch isotherms at 25 degrees C. The pH range was 4-9, using various initial concentrations up to a maximum of approximately 30 uM. For all anionic species studied, the capacity decreased with increasing pH, and the reverse trend was noted for cadmium. The Langmuir model provided a good fit for the anionic isotherms and the Freundlich model for the cationic isotherms. The materials studied possessed a markedly higher capacity for fluoride than arsenate and phosphate, with an intermediate capacity for cadmium. This indicates that fluoride is attached to the surface via monodentate (single) bonds, whilst both arsenate and phosphate are primarily attached to the surface via bidentate (two) bonds. Cadmium is probably bound by both these mechanisms. The effect of competing anions on arsenic uptake capacity was determined using mini-column experiments of binary (arsenate-fluoride, arsenate-Phosphate and phosphate-fluoride) and ternary (arsenate-fluoride-phosphate) mixtures. Arsenate removal was strongly affected by the presence of phosphate, but was only slightly lower in the presence of fluoride. (Continues...).

Es calcula que prop d'un 95% de la biomassa bacteriana que es pot trobar en els sistemes de distribució d'aigua potable es troba localitzada adherida a les superfícies internes de les canonades en forma de biopel·lícules, i que només un 5% es troba lliure en la fase aquosa. El creixement dels microorganismes formant biofilms sobre les superfícies altera la composició dels materials. En el cas de les superfícies metàl·liques, les reaccions fisicoquímiques es tradueixen en canvis indesitjables que es veuen agreujades per la biocorrosió o la corrosió influenciada per microorganismes. El coure és un element traça essencial, però ingerit de forma massiva és tòxic. S'han descrit casos d'intoxicacions a causa de problemes de corrosió i cuprosolvència on els microorganismes juguen un paper primordial. Alhora, alguns bacteris formadors del biofilms tenen la capacitat d'acumular el metall, incrementant el risc per la salut pública. Aquest treball posa de manifest com Agrobacterium radiobacter EPS-916 és capaç de captar coure provinent de solucions aquoses de CuSO4.5H2O, a diferents concentracions, així com el seu exopolisacàrid. Mitjançant microscòpia electrònica de transmissió s'ha comprovat que la captació del coure per part del microorganisme és intracel·lular, observant-se cúmuls densos en el citoplasma dels bacteris. A més s'ha aïllat Pseudomonas putida-M16 de les canonades de coure d'ús domèstic i ha demostrat una resistència elevada a la sal de coure, essent també capaç d'acumular-lo. A més les dues soques han estat capaces de captar el metall quan aquest es presenta en forma de superfície cúprica en cupons de coure i superficies de canonades. Per concloure l'estudi les imatges obtingues mitjançant microscòpia de rastreig han demostrat la presència de biopel·lícules tant en les superfícies cúpriques estudiades, així com en la superfície interior d'una secció de canonada de coure després d'un període aproximat de dos anys en contacte amb aigua. / In their natural environments, bacteria don't exist as isolated cells but grow and survive in organized communities commonly referred to as biofilms. Biofilms are differentiaded masses of microbes that form on surfaces and are surrounded by an extracellular matrix (EPS). Generally, biofouling can be defined as the undesired accumulation of deposits of a biological nature on surface. The former was defined as the process resulting from the accumulation of microbial biofilms consisting of: microorganisms, polymeric materials secreted by theses organisms, particulate matter of different origin, and, mainly of water. The accumulation of biofilms on copper plumbing pipes is well established. Biofilms have been implicated in the corrosion of copper plumbing, Known as cuprosolvency, which results in increases in soluble copper concentrations in drinking water supplies.This has significant implications for public health as the consumption of copper in water at levels exceeding 2mg/mL can cause adverse gastrointestinal symptoms in humans. This study investigated the capacity of Agrobacterium radiobacter EPS-916 to uptake copper from aqueous solutions of copper sulfate, and its skill to form biofilms in a copper plumbing. On the other hand our work want to show how biofilm bacteria isolated from domestic copper plumbing contributed to cuprosolvency and by scanning electron microscopy we can see the biofilm formation in copper surfaces.

Thèse (M.ATDR)--Université Laval, 2006. / Bibliogr.: f. 84-88. Publié aussi en version électronique dans la Collection Mémoires et thèses électroniques.

El documento digital no refiere asesor / Aborda el análisis de datos de volumen, caudal y presión de agua potable del sector 18 ubicado en el distrito de San Borja con la finalidad de lograr la reducción de la tasa de agua no facturada (ANF) en el sector, puesto que las pérdidas de agua potable en las redes de distribución y conexiones son elevadas lo cual conlleva a pérdidas económicas a la empresa prestadora de servicio. Para ello la elección del sector bajo análisis se realizó de acuerdo a su alta tasa de ANF, al alto nivel de micromedición a través de medidores domésticos y a que es un área monitoreada por el Sistema SCADA (Supervisory Control And Data Acquisition) de la empresa. A continuación se evaluó el nivel de micromedición del sector comparando la cantidad de conexiones con lectura de consumo respecto del total de conexiones determinándose que si se incrementa la cantidad de conexiones leídas se reduce el agua no facturada. Se evaluaron las pérdidas de agua potable en las redes de distribución por fugas o conexiones clandestinas comparando los volúmenes de agua entregada a la red y los volúmenes de agua consumidos en el sector, encontrándose la existencia de un gran volumen de agua pérdida predominantemente por fugas de las redes. Asimismo, se constató que una sobreelevación en el valor de la presión en el ingreso del sector conlleva a una mayor pérdida de volumen de agua. En conclusión se determinó que un adecuado control en las mediciones de las conexiones domiciliarias, pérdidas de volumen por fugas se puede lograr una reducción de la tasa de ANF. / Trabajo de suficiencia profesional