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A proposta do modelo computacional (DIMREDE) para dimensionamento de redes coletoras de esgotos sanitários de grande porte, a partir de um traçado conhecido, fundamenta-se na sua importância sanitária e ambiental, e na necessidade de minimizar os custos totais de tais sistemas. O modelo é destinado a microcomputadores, atendendo, portanto, aos requisitos de portabilidade. As redes de esgoto são projetadas para o regime de escoamento livre, embora em alguns casos, seja necessária a introdução de estações elevatórias em determinados pontos do sistema. O modelo prevê a incorporação dessas elevatórias, quando necessário, adicionando os respectivos custos no cômputo dos custos totais. As funções de custos utilizadas são baseadas em dados de redes executadas por companhias de saneamento do país. O DIMREDE permite também que, a equação governante da hidráulica de Hazen-Williams modificada, seja empregada. Trata-se de uma expressão que contempla fatores como a lâmina e velocidade de escoamento, diâmetro, declividade, material empregado no revestimento do conduto e viscosidade do fluido, na determinação do coeficiente de rugosidade, apresentando, desta forma, resultados mais condizentes com a realidade. / A computational model (DIMREDE) is proposed for design of large sewer networks whose layouts whose layouts are defined, based on their sanitary and environmental importance, as well as the costs minimization. The model is designed for microcomputers satisfying the portability criterion. In spite of the sewer networks being designed under free flow, many times the introduction of pump stations in such systems is necessary. The model evaluates costs of pump stations as part of the total cost function in terms of sewer networks already implemented by sanitation companies in Brazil. The DIMREDE program employs the modified Hazen-Williams equation for the system hydraulics, admiting that factors like depth, velocity, diameter, slope, lining material and fluid viscosity be considered in the determination of the coefficient of roughness, for obtaining more realistic results.

A proposta do modelo computacional (DIMREDE) para dimensionamento de redes coletoras de esgotos sanitários de grande porte, a partir de um traçado conhecido, fundamenta-se na sua importância sanitária e ambiental, e na necessidade de minimizar os custos totais de tais sistemas. O modelo é destinado a microcomputadores, atendendo, portanto, aos requisitos de portabilidade. As redes de esgoto são projetadas para o regime de escoamento livre, embora em alguns casos, seja necessária a introdução de estações elevatórias em determinados pontos do sistema. O modelo prevê a incorporação dessas elevatórias, quando necessário, adicionando os respectivos custos no cômputo dos custos totais. As funções de custos utilizadas são baseadas em dados de redes executadas por companhias de saneamento do país. O DIMREDE permite também que, a equação governante da hidráulica de Hazen-Williams modificada, seja empregada. Trata-se de uma expressão que contempla fatores como a lâmina e velocidade de escoamento, diâmetro, declividade, material empregado no revestimento do conduto e viscosidade do fluido, na determinação do coeficiente de rugosidade, apresentando, desta forma, resultados mais condizentes com a realidade. / A computational model (DIMREDE) is proposed for design of large sewer networks whose layouts whose layouts are defined, based on their sanitary and environmental importance, as well as the costs minimization. The model is designed for microcomputers satisfying the portability criterion. In spite of the sewer networks being designed under free flow, many times the introduction of pump stations in such systems is necessary. The model evaluates costs of pump stations as part of the total cost function in terms of sewer networks already implemented by sanitation companies in Brazil. The DIMREDE program employs the modified Hazen-Williams equation for the system hydraulics, admiting that factors like depth, velocity, diameter, slope, lining material and fluid viscosity be considered in the determination of the coefficient of roughness, for obtaining more realistic results.

Apresenta-se um estudo de caso realizado nas cidades de São Carlos e Araraquara, Estado de São Paulo, em que são analisados problemas nos pavimentos associados aos serviços de manutenção da infra-estrutura de água e esgoto, tanto em nível de rede como em nível de projeto. Investiga-se a possibilidade de compatibilização da gerência de pavimentos com a gerência de outras infra-estruturas e analisam-se as normas dos serviços, os métodos de execução efetivamente utilizados e os procedimentos de controle e garantia da qualidade. Os resultados mostram a necessidade de implementação de sistemas racionais de gerenciamento de infra-estruturas pelas prefeituras e concessionárias de serviços públicos e o desenvolvimento de regulamentações, manuais e guias para restauração dos pavimentos após os serviços de manutenção das redes, com um controle mais rigoroso dos procedimentos técnicos. / It is presented a case study performed in the cities of Sao Carlos and Araraquara, state of Sao Paulo, Brazil. It analyses pavement problems associated to the maintenance of water and sewer infrastructure networks at both network and project levels. It investigates the possibilities of integration of the pavement management to the management of other infrastructures and it analyses the service regulations, the construction methods effectively used and the quality control/quality assurance (QC/QA) procedures. The results show the necessity of the implementation of a rational infrastructure management system by the cities and urban agencies, and the development of regulations, manuals and guidelines for pavement restoration after the maintenance of water and sewer networks, which will allow a more effective enforcement of the technical standards.

Apresenta-se um estudo de caso realizado nas cidades de São Carlos e Araraquara, Estado de São Paulo, em que são analisados problemas nos pavimentos associados aos serviços de manutenção da infra-estrutura de água e esgoto, tanto em nível de rede como em nível de projeto. Investiga-se a possibilidade de compatibilização da gerência de pavimentos com a gerência de outras infra-estruturas e analisam-se as normas dos serviços, os métodos de execução efetivamente utilizados e os procedimentos de controle e garantia da qualidade. Os resultados mostram a necessidade de implementação de sistemas racionais de gerenciamento de infra-estruturas pelas prefeituras e concessionárias de serviços públicos e o desenvolvimento de regulamentações, manuais e guias para restauração dos pavimentos após os serviços de manutenção das redes, com um controle mais rigoroso dos procedimentos técnicos. / It is presented a case study performed in the cities of Sao Carlos and Araraquara, state of Sao Paulo, Brazil. It analyses pavement problems associated to the maintenance of water and sewer infrastructure networks at both network and project levels. It investigates the possibilities of integration of the pavement management to the management of other infrastructures and it analyses the service regulations, the construction methods effectively used and the quality control/quality assurance (QC/QA) procedures. The results show the necessity of the implementation of a rational infrastructure management system by the cities and urban agencies, and the development of regulations, manuals and guidelines for pavement restoration after the maintenance of water and sewer networks, which will allow a more effective enforcement of the technical standards.

La nécessité de rénover les réseaux d'assainissement des grandes villes et les besoins de construire de nouvelles structures conduisent les gestionnaires de réseaux d'assainissement et les fabricants de canalisation à rechercher des solutions pour obtenir des installations d'assainissement durables. Parmi les détériorations rencontrées dans ces structures, 9% peuvent être attribués à la biodétérioration des matériaux cimentaires. Cette étude a deux objectifs principaux. Le premier est de développer un essai accéléré reproductible en laboratoire et qui donne des résultats proches de ceux obtenus sur site. Le second est d'étudier la biodétérioration des matériaux cimentaires pour mieux comprendre les mécanismes et plus spécifiquement la différence de comportement entre les matériaux à base de ciment d'aluminate de calcium (CAC) et de ciment Portland ordinaire (OPC). Dans ce cadre, différentes formulations cimentaires ont été exposées in situ afin de déterminer les paramètres influant sur la biodétérioration. En parallèle, des expériences en laboratoire ont été réalisées pour mieux comprendre chaque étape du mécanisme de biodétérioration. Les résultats des expositions sur site montrent que les matériaux à base de CAC ont une durabilité plus importante que les autres formulations cimentaires. Les études réalisées en laboratoire permettent d'attribuer ces meilleures performances à la teneur en aluminium qui inhibe la croissance des microorganismes tout en protégeant la matrice grâce à la précipitation d'une couche d'alumine hydratée dans la porosité et à la surface de ces matériaux et qui maintient le pH à 3,5-4. La chimie de surface a également un rôle important en favorisant ou non l'oxydation abiotique de l'H2S. Les résultats des expositions sur site et des différents essais de laboratoire ont été utilisés pour développer un essai accéléré donnant des résultats prometteurs / The need for renovation of sewer networks in major cities and the necessity to build new structures lead managers of sewer pipe and manufacturers to seek for solutions for sustainable sanitation. 9% of damages encountered in these structures can be attributed to the biodeterioration of cementitious materials. This study has two main objectives. The first one is to develop an accelerated reproducible laboratory test that gives results similar to those obtained on site. The second is to study the biodeterioration of cementitious materials in order to better understand mechanisms and more especially the difference in behavior between materials based on calcium aluminate cement (CAC) and ordinary Portland cement (OPC). Within this framework, different cement formulations were exposed in situ to identify the parameters influencing biodeterioration. Meanwhile, laboratory experiments were conducted to better understand each step of the mechanism of biodeterioration. Results of on site exposition show that materials based on CAC have a greater durability than other cement formulations. Laboratory studies assign these best performances to the aluminum content which inhibits the growth of microorganisms while protecting the matrix by precipitation of a hydrated alumina layer in the porosity and on the surface of these materials. This layer maintains the pH at 3.5-4. Surface chemistry was shown to play an important role in catalizing abiotic oxidation of H2S. The results of on-site exhibitions and various laboratory tests were used to develop an accelerated test giving promising results

Une part importante de la détérioration des réseaux d’assainissement en matériau cimentaire est d’origine biologique. Dans ce contexte, les matériaux à base de ciment alumineux ont montré une meilleure durabilité que ceux à base de ciment Portland ordinaire, couramment utilisés. Les hypothèses de la littérature qui expliqueraient cette meilleure résistance sont centré sur l’aluminium (présent à plus de 50% dans les ciments alumineux pour seulement 5% dans les ciments Portland). L’objectif de cette thèse est de caractériser et hiérarchiser les mécanismes de résistance des matériaux cimentaires lors de la biodétérioration. Cela permettra de comprendre le rôle de l’aluminium dans les interactions entre les microorganismes et les matériaux cimentaires. Après des études en réacteur et des tests de biodétérioration de pâte de ciments en laboratoire, il semblerait que la principale cause de résistance est due à la réactivité des matrices cimentaires plus qu’à un effet inhibiteur de l’aluminium ou du matériau sur les microorganismes. / An important part of the deterioration observed in concrete sewer networks is due to biological activity. In this context, calcium aluminate cement (CAC) based material has shown a better durability than ordinary Portland cement, usually used in such context. In literature, hypothesis explaining the better resistance are focused on aluminium. The aim of the project is to characterize the role of aluminium in the interactions between cementitious material and microorganisms. Reactor study and Lab scale aggressive biodeterioration protocol of cementitious material revealed that the better resistance of CAC is due to their lower reactivity and not to a bacteriostatic effect of the material on the microorganisms.

Thesis (MPA.) -- University of Limpopo, 2019 / Polokwane Municipality is currently experiencing water shortages, which is affecting households and industries’ which is used to remove faeces and transport them to the sewage plant through sewer networks, as the system is waterborne. This research study aims at determining the status of faecal sludge management with the aim of developing a faecal sludge management projection plan for the City of Polokwane. The plan will enable the city to understand the current and future levels of faecal sludge production and it will also highlight the water demand for faecal sludge disposal. As a result of this plan, the appropriate systems, which can be used for faecal sludge production, can be managed better and there will be relief in the current non-coping sewage plants in the municipality. The sewage plants are not coping with the amount of faecal sludge due to the growing population and the fact that the infrastructure was built before South Africa’s 1994 democratic dispensation. The empirical enquiry was conducted through the use of the interview guide and the purposive sampling strategy in order to obtain an in-depth context of the subject being studied. The study has noted that the Seshego and Polokwane Sewage Plants are receiving more sewage than they were built for. The only plant that is still within its capacity is the Mankweng Sewage Plant. Currently, the municipality does not have alternative plan to re-use water in the yards. It is also not planning to develop any other form of faecal sludge management to transport faeces from the toilets to the sewage plants despite the use of clean water. It is questionable as to whether the cleaned water or effluent released from the sewage to the environment meet the required standards. In Polokwane, the released effluent does not go back to the people directly but it is used to recharge 37 boreholes, which are used to supply water to the people. The other challenge in Polokwane Municipality, especially in Mankweng, is the petrol stations, hospitals, and abattoirs whose effluents are creating a problem to the water treatment plants. Therefore, there is a need to have a pre-treatment plants for hospitals and filling stations. Key Words: Sanitation, faeces, faecal sludge, sewage plants and water borne.