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Integrated simulation and optimum control of the urban wastewater systemSchuetze, Manfred Richard January 1998 (has links)
No description available.
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Bedömningsgrunder och reningskrav för avloppsreningsverk, 25-2000 pe, i Laholms kommunAbrahamsson, Anna, Ljunggren, Mona January 2008 (has links)
<p>The aim of this project was to look into ten small sewer systems in the municipality of Laholm, in Sweden, in order to work out common assessment grounds for them. The sizes of the systems for purification of wastewater were within the range of 25 to 2000 population equivalents. Our method was to study literature, the laws and regulations applicable and the files at the municipality. The conclusion is that every sewer system is different and every situation is unique. We concluded that based on laws and assessment grounds sewer systems equal in size and pollution load ought to have similar demands attached to them. Four of the sewer systems are in need of adjustments or renovations. One sewer system in particular, Hishult, needs large-scale adjustments and improvements to live up to the demands attached to it. This sewer system is where we think the focus from the municipality ought to be the strongest, based on the result from this review. It requires most effort, time and money, to get it running with least amount of environmental impact. We also suggested levels for degree of purification for all of the sewer systems. As a common ground we set the demands equal to the ones for private sewer systems. The demand for purification of phosphorus was adjusted to if the system was equipped with chemical precipitation or not. Subsurface filters are left without measures. The focus of demands on systems of that kind is set to new construction or full scale restoration.</p>
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Bedömningsgrunder och reningskrav för avloppsreningsverk, 25-2000 pe, i Laholms kommunAbrahamsson, Anna, Ljunggren, Mona January 2008 (has links)
The aim of this project was to look into ten small sewer systems in the municipality of Laholm, in Sweden, in order to work out common assessment grounds for them. The sizes of the systems for purification of wastewater were within the range of 25 to 2000 population equivalents. Our method was to study literature, the laws and regulations applicable and the files at the municipality. The conclusion is that every sewer system is different and every situation is unique. We concluded that based on laws and assessment grounds sewer systems equal in size and pollution load ought to have similar demands attached to them. Four of the sewer systems are in need of adjustments or renovations. One sewer system in particular, Hishult, needs large-scale adjustments and improvements to live up to the demands attached to it. This sewer system is where we think the focus from the municipality ought to be the strongest, based on the result from this review. It requires most effort, time and money, to get it running with least amount of environmental impact. We also suggested levels for degree of purification for all of the sewer systems. As a common ground we set the demands equal to the ones for private sewer systems. The demand for purification of phosphorus was adjusted to if the system was equipped with chemical precipitation or not. Subsurface filters are left without measures. The focus of demands on systems of that kind is set to new construction or full scale restoration.
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A multi-objective approach to incorporate indirect costs into optimisation models of waterborne sewer systemsBester, Albertus J. 03 1900 (has links)
Thesis (MScEng (Civil Engineering))--University of Stellenbosch, 2011. / ENGLISH ABSTRACT: Waterborne sewage system design and expansion objectives are often focused on
minimising initial investment while increasing system capacity and meeting
hydraulic requirements. Although these objectives make good sense in the short
term, the solutions obtained might not represent the optimal cost-effective
solution to the complete useful life of the system. Maintenance and operation of
any system can have a significant impact on the life-cycle cost. The costing
process needs to be better understood, which include maintenance and operation
criteria in the design of a sewer system. Together with increasing public
awareness regarding global warming and environmental degradation,
environmental impact, or carbon cost, is also an important factor in decisionmaking
for municipal authorities. This results in a multiplicity of different
objectives, which can complicate the decisions faced by waterborne sewage
utilities.
Human settlement and migration is seen as the starting point of expansion
problems. An investigation was conducted into the current growth prediction
models for municipal areas in order to determine their impact on future planning
and to assess similarities between the models available. This information was used
as a platform to develop a new method incorporating indirect costs into models
for planning waterborne sewage systems.
The need to balance competing objectives such as minimum cost, optimal
reliability, and minimum environmental impact was identified. Different models
were developed to define the necessary criteria, thus minimising initial
investment, operating cost and environmental impact, while meeting hydraulic
constraints. A non-dominated sorting genetic algorithm (NSGA-II) was applied to
certain waterborne sewage system (WSS) scenarios that simulated the
evolutionary processes of genetic selection, crossover, and mutation to find a
number of suitable solutions that balance all of the given objectives. Stakeholders
could in future apply optimisation results derived in this thesis in the decision making process to find a solution that best fits their concerns and priorities.
Different models for each of the above-mentioned objectives were installed into a
multi-objective NSGA and applied to a hypothetical baseline sewer system
problem. The results show that the triple-objective optimisation approach supplies
the best solution to the problem. This approach is currently not applied in practice
due to its inherent complexities. However, in the future this approach may become
the norm. / AFRIKAANSE OPSOMMING: Spoelafvoering rioolstelsel ontwerp en uitbreiding doelwitte is dikwels gefokus op
die vermindering van aanvanklike belegging, terwyl dit die verhoging van stelsel
kapasiteit insluit en ook voldoen aan hidrouliese vereistes. Alhoewel hierdie
doelwitte goeie sin maak in die kort termyn, sal die oplossings verkry dikwels nie
die optimale koste-effektiewe oplossing van die volledige nuttige lewensduur van
die stelsel verteenwoordig nie. Bedryf en instandhouding van 'n stelsel kan 'n
beduidende impak op die lewensiklus-koste hê, en die kostebepalings proses moet
beter verstaan word en die nodige kriteria ingesluit word in die ontwerp van 'n
rioolstelsel. Saam met 'n toenemende openbare bewustheid oor aardverwarming
en die agteruitgang van die omgewing, is omgewingsimpak, of koolstof koste, 'n
belangrike faktor in besluitneming vir munisipale owerhede. As gevolg hiervan,
kan die diversiteit van die verskillende doelwitte die besluite wat munisipale
besluitnemers in die gesig staar verder bemoeilik.
Menslike vestiging en migrasie is gesien as die beginpunt van die uitbreiding
probleem. 'n Ondersoek na die huidige groeivoorspelling modelle vir munisipale
gebiede is van stapel gestuur om hul impak op die toekomstige beplanning te
bepaal, en ook om die ooreenkomstes tussen die modelle wat beskikbaar is te
asesseer. Hierdie inligting is gebruik as 'n platform om ‘n nuwe metode te
ontwikkel wat indirekte kostes inkorporeer in die modelle vir die beplanning van
spoelafvoer rioolstelsels.
Die behoefte is geïdentifiseer om meedingende doelwitte soos minimale
aanvanklike koste, optimale betroubaarheid en minimum invloed op die
omgewing te balanseer. Verskillende modelle is ontwikkel om die bogenoemde
kriteria te definiëer, in die strewe na die minimaliseering van aanvanklike
belegging, bedryfskoste en omgewingsimpak, terwyl onderhewig aan hidrouliese
beperkinge. ‘n Nie-gedomineerde sorteering genetiese algoritme (NSGA-II),
istoegepas op sekere spoelafvoering rioolstelsel moontlikhede wat gesimuleerde
evolusionêre prosesse van genetiese seleksie, oorplasing, en mutasie gebruik om 'n aantal gepaste oplossings te balanseer met inagname van al die gegewe
doelwitte. Belanghebbendes kan in die toekoms gebruik maak van die resultate
afgelei in hierdie tesis in besluitnemings prosesse om die bes-passende oplossing
vir hul bekommernisse en prioriteite te vind. Verskillende modelle vir elk van die
bogenoemde doelwitte is geïnstalleer in die nie-gedomineerde sorteering genetiese
algoritme en toegepas op 'n hipotetiese basislyn rioolstelsel probleem. Die
resultate toon dat die drie-objektief optimalisering benadering die beste oplossing
vir die probleem lewer. Hierdie benadering word tans nie in die praktyk toegepas
nie, as gevolg van sy inherente kompleksiteite. Desnieteenstaande, kan hierdie
benadering in die toekoms die norm word.
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Savitakio ir vakuuminio nuotakyno palyginamoji analizė / Gravity and vacuum sewer system comparison analysisNavickas, Marius 14 January 2009 (has links)
Magistro studijų baigiamasis darbas, 58 puslapiai, 46 paveikslai, 10 lentelės, 32 literatūros šaltiniai, 9 lietuvių kalba ir 23 už sienio kalba Tyrimo objektas – Vakuuminis ir savitakinis nuotakynas. Darbo tikslas – atlikti vakuuminio ir savitakinio nuotakyno palyginamąją analizę. Uždaviniai: 1. Išanalizuoti sistemų privalumus ir trūkumus; 2. Suprojektuoti savitakinį ir vakuuminį tinklą pasirinktai gyvenvietei; 3. Atlikti suprojektuotų tinklų ekonominė analizė Tyrimo metodai – lietuvių ir už sienio mokslinės literatūros lyginamoji analizė, scheminio vaizdavimo metodas, projektavimas. Išstudijavus Lietuvių ir užsienio literatūrą apie vakuuminį bei savitakinį nuotakyną, apžvelgta dabartinė nuotakynų būklė Lietuvoje, atlikta palyginamoji analizė, nustatyti pagrindiniai sistemų privalumai bei trūkumai, apžvelgtos vakuuminės sistemos pritaikymo sritys. Vilniaus raj. Sakališkių gyvenvietei suprojektuoto vakuuminio bei savitakinio tinklo analizė parodė, kad vakuuminio nuotakyno statybos kaštai yra beveik dvigubai mažesni negu savitakinio. Atlikta analizė parodė, kad vakuuminiai nuotakynai yra perspektyvūs tam tikromis sąlygomis, tačiau Lietuvoje nepagristai nenaudojami. Vakuuminiai nuotakynai yra nepakeičiami projektuojant lygiose, retai apgyvendintose kaimiškose vietovėse. Priimant sprendimą dėl gyvenvietės nuotekų sistemos pasirinkimo, turi būti atliktas bent dviejų skirtingų sistemų variantų palyginimas. / Master degree final work consists of 58 pages, 46 pictures, 10 tables and 32 literatures. Test object – Vacuum and gravity system. Work purpose is to perform vacuum and gravity sewer system’s comparison analysis. Main tasks: 1. Analyze systems advantages and disadvantages; 2. Project gravity and vacuum systems for chosen village; 3. Perform economical analysis for projected systems; Test methods are Lithuanian and foreign scientific literatures comparison analysis, schematic representation method, planning. Overviewed Lithuanian and foreign scientific literature about vacuum and gravity sewer system was overlooked now days sewer situation in Lithuania, completed systems comparison analysis, identified the main systems advantages and disadvantages, overlooked vacuum sewer systems appliances areas, for Sakaliskes village was projected vacuum and gravity systems. Accomplished analysis showed that vacuum sewers are perspective under certain conditions, but in Lithuania interfere unused. Vacuum sewers are unchangeable in flat territories and in rural areas. Before project starts, there should be completed comparison of vacuum, gravity and pressure sever systems.
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Materiais de tubulações utilizadas em sistemas de coleta e transporte de esgotos sanitários: estudo de caso da área norte de São Paulo. / Pipes materials used in sanitary sewer systems: case study of the northern area of São Paulo.Bevilacqua, Nelson 06 October 2006 (has links)
Este trabalho descreve os diversos materiais que podem ser utilizados nas tubulações de sistemas de esgotos sanitários, apresenta suas principais características, a hidráulica das tubulações, principais fabricantes, aspectos construtivos, operação e manutenção e comentam-se as normas técnicas referentes a esses materiais. Os dados apresentados foram obtidos através de pesquisa na área norte de São Paulo cujo sistema é operado pela Sabesp, consultando-se as unidades funcionais de projeto, apoio técnico, operação, manutenção e obras da Sabesp. Destaca-se a preferência pelo uso das tubulações de PVC para a implantação e manutenção das ligações prediais e redes coletoras devido às vantagens de sua aplicação, tais como: facilidade de transporte e manuseio, maior produtividade, menos problemas operacionais, praticidade e segurança. Para coletores de maiores diâmetros e interceptores há preferência pelos tubos de PRFV, PVC e PEAD e pelo sistema de tubo de concreto cravado. Na escolha do melhor material a ser utilizado, deve-se considerar além das características dos esgotos, a resistência, a disponibilidade, a facilidade de transporte, e custos desse material . Deve-se, também se levar em conta, o método aplicado na construção e as condições locais da obra. Como principais conclusões, destaca-se a viabilidade econômica da utilização do PVC em relação ao tubo cerâmico nas obras de redes e ligações, e a tendência da utilização de PRFV e PEAD na implantação de novos coletores com diâmetro de 300 a 500mm. Recomenda-se a utilização de juntas elásticas nas tubulações cerâmicas e a especificação do tipo de material precedida de estudos amplos de viabilidade que considerem a sua vida útil, praticidade de aplicação, custos, aspectos ambientais, operação, manutenção, segurança e rapidez na implantação da obra. / This dissertation describes the various materials used in sanitary sewer systems, presents their main characteristics, pipeline hydraulics and manufacturers. It also features construction, operational and maintenance aspects for the different materials as well as the technical regulations concerning these materials. Data were collected in the Northern area of São Paulo, whose sewer system is operated by Sabesp, through research in the following functional units: project, technical support, operations, maintenance and construction. This study highlights the operation area\'s preference for PVC pipes for building and maintenance of sewage connections and sewers because its advantages such as: ease of transportation and handling, greater productivity, less operational problems, practicity and safety. For large diameter trunk sewers and interceptors, FRP (Fiberglass reinforced plastic), PVC (Polyvinyl chloride) and PE (Polyethylene) pipes and Jacking Pipe system are usually the choice. In the selection of the best material, one should consider the wastewater characteristics and the material resistance, availability, ease of transportation and cost. The construction methods and local conditions should also be taken into account in this process. In conclusion, this study stresses the economical viability of PVC pipes over ceramical pipes in sewers and connections, the tendency to use FRP and PE in new 300 - to 500- mm- diameter trunk sewers and recommendation for the use of elastic joints with ceramical pipes. Lastly, the specification of the type of material to be used should be preceded by broad viability studies that consider its required life, practicity, cost, environmental aspects, operational and maintenance aspects and safety in the building process.
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Elaboración de concreto antibacterial mediante ensayos de laboratorio con el fin de evaluar la durabilidad y reducir costos de mantenimiento en estructuras de sistemas de alcantarillado en Lima Metropolitana / Antibacterial concrete production through laboratory tests in order to evaluate durability and reduce maintenance costs applied in sewer systems structures in Lima MetropolitanaUmeres Acurio, Mavi Alejandra, Chavez Perea, Mauricio Enrique 23 July 2019 (has links)
La corrosión del concreto es uno de los principales problemas de deterioro y pérdida de funcionalidad que puede llevar al colapso parcial o total de una estructura. En los sistemas de alcantarillado existe un proceso denominado Corrosión Microbiana Inducida, el cual es causado por la acción del consorcio de bacterias presentes en las aguas residuales, las mismas que generan ácido sulfúrico como parte de su metabolismo.
El trabajo experimental desarrollado comienza con la preparación y muestreo de un diseño de concreto patrón y tres de concreto antibacterial con diferente dosificación de Aditivo Antimicrobial, los cuales fueron evaluados por un ensayo microbiológico. En esta etapa se determinó la dosis de aditivo con la que se realizarán nuevos diseños.
Como alternativa de solución frente al ataque de ácido sulfúrico se realizó en laboratorio la preparación y muestreo de seis diseños de concreto, para los cuales se establece algunas variables de estudio: relación agua/cemento y porcentaje de adición mineral Filler Calizo. Las propiedades del concreto se evaluaron mediante ensayos en estado endurecido. Asimismo, se determinó la resistencia del concreto frente a concentraciones de 3%, 5% y 7% de ácido sulfúrico; el rendimiento se evaluó mediante la pérdida de peso.
Finalmente, se realizó una evaluación económica en base a un proyecto de Saneamiento, en el cual se determinó el presupuesto para la construcción de buzones considerando los costos del concreto patrón y antibacterial elegido. Para determinar la rentabilidad económica se consideró los costos por mantenimiento para un periodo de análisis de 20 años. / The experimental work developed begins with the preparation and sampling of a single concrete pattern design and three antibacterial concrete designs with different dosage of Antimicrobial Additive, which are evaluated through a microbiological test. This consists in the exposure of the concrete samples at the consortium of bacteria present in a wastewater treatment plant. The effectiveness of the additive under study was determined by a visual analysis of the coloration, pH variation and then compared to the results of the concrete pattern design.
As an alternative solution for sulfuric acid attack, the preparation, sampling and control of six concrete designs was carried out in laboratory, for which some study variables were established: the water / cement ratio and the mineral addition percentage of Filler Limestone. The durability of the concrete was evaluated by hardened destructive and non-destructive tests. Likewise, the resistance of the concrete was determined against concentrations of 3%, 5% and 7% of sulfuric acid, for an exposure time of 4 and 8 weeks and analyzed by the weight loss.
Finally, an economic evaluation was carried out based on a sanitary project, in which the budget for the construction of mailboxes was determined considering the costs of the standard and antibacterial concrete previously chosen. To determine the benefit, a schedule was established with the items of preventive and corrective maintenance according to the frequency and necessity of each design. The results were presented through a flow of expenditures for a period of analysis of 20 years. / Tesis
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Materiais de tubulações utilizadas em sistemas de coleta e transporte de esgotos sanitários: estudo de caso da área norte de São Paulo. / Pipes materials used in sanitary sewer systems: case study of the northern area of São Paulo.Nelson Bevilacqua 06 October 2006 (has links)
Este trabalho descreve os diversos materiais que podem ser utilizados nas tubulações de sistemas de esgotos sanitários, apresenta suas principais características, a hidráulica das tubulações, principais fabricantes, aspectos construtivos, operação e manutenção e comentam-se as normas técnicas referentes a esses materiais. Os dados apresentados foram obtidos através de pesquisa na área norte de São Paulo cujo sistema é operado pela Sabesp, consultando-se as unidades funcionais de projeto, apoio técnico, operação, manutenção e obras da Sabesp. Destaca-se a preferência pelo uso das tubulações de PVC para a implantação e manutenção das ligações prediais e redes coletoras devido às vantagens de sua aplicação, tais como: facilidade de transporte e manuseio, maior produtividade, menos problemas operacionais, praticidade e segurança. Para coletores de maiores diâmetros e interceptores há preferência pelos tubos de PRFV, PVC e PEAD e pelo sistema de tubo de concreto cravado. Na escolha do melhor material a ser utilizado, deve-se considerar além das características dos esgotos, a resistência, a disponibilidade, a facilidade de transporte, e custos desse material . Deve-se, também se levar em conta, o método aplicado na construção e as condições locais da obra. Como principais conclusões, destaca-se a viabilidade econômica da utilização do PVC em relação ao tubo cerâmico nas obras de redes e ligações, e a tendência da utilização de PRFV e PEAD na implantação de novos coletores com diâmetro de 300 a 500mm. Recomenda-se a utilização de juntas elásticas nas tubulações cerâmicas e a especificação do tipo de material precedida de estudos amplos de viabilidade que considerem a sua vida útil, praticidade de aplicação, custos, aspectos ambientais, operação, manutenção, segurança e rapidez na implantação da obra. / This dissertation describes the various materials used in sanitary sewer systems, presents their main characteristics, pipeline hydraulics and manufacturers. It also features construction, operational and maintenance aspects for the different materials as well as the technical regulations concerning these materials. Data were collected in the Northern area of São Paulo, whose sewer system is operated by Sabesp, through research in the following functional units: project, technical support, operations, maintenance and construction. This study highlights the operation area\'s preference for PVC pipes for building and maintenance of sewage connections and sewers because its advantages such as: ease of transportation and handling, greater productivity, less operational problems, practicity and safety. For large diameter trunk sewers and interceptors, FRP (Fiberglass reinforced plastic), PVC (Polyvinyl chloride) and PE (Polyethylene) pipes and Jacking Pipe system are usually the choice. In the selection of the best material, one should consider the wastewater characteristics and the material resistance, availability, ease of transportation and cost. The construction methods and local conditions should also be taken into account in this process. In conclusion, this study stresses the economical viability of PVC pipes over ceramical pipes in sewers and connections, the tendency to use FRP and PE in new 300 - to 500- mm- diameter trunk sewers and recommendation for the use of elastic joints with ceramical pipes. Lastly, the specification of the type of material to be used should be preceded by broad viability studies that consider its required life, practicity, cost, environmental aspects, operational and maintenance aspects and safety in the building process.
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Leveraging Big Data and Deep Learning for Economical Condition Assessment of Wastewater PipelinesSrinath Shiv Kumar (8782508) 30 April 2020 (has links)
<p>Sewer pipelines are an essential
component of wastewater infrastructure and serve as the primary means for
transporting wastewater to treatment plants. In the face of increasing demands
and declining budgets, municipalities across the US face unprecedented
challenges in maintaining current service levels of the 800,000 miles of public
sewer pipes. Inadequate maintenance of sewer pipes leads to inflow and
infiltration, sanitary sewer overflows, and sinkholes, which threaten human
health and are expensive to correct. Accurate condition information from sewers
is essential for planning maintenance, repair, and rehabilitation activities
and ensuring the longevity of sewer systems. Currently, this information is
obtained through visual closed-circuit television (CCTV) inspections and
deterioration modeling of sewer pipelines. CCTV inspection facilitates the
identification of defects in pipe walls whereas deterioration modeling
estimates the remaining service life of pipes based on their current condition.
However, both methods have drawbacks that limit their effective usage for sewer
condition assessment. For instance, CCTV inspections tend to be labor
intensive, costly, and time consuming, with the accuracy of collected data
depending on the operator’s experience and skill level. Current deterioration
modeling approaches are unable to incorporate spatial information about pipe
deterioration, such as the relative locations, densities, and clustering of
defects, which play a crucial role in pipe failure. This study attempts to
leverage recent advances in deep learning and data mining to address these
limitations of CCTV inspection and deterioration modeling and consists of three
objectives. </p>
<p> </p>
<p>The first objective of this study seeks to develop
algorithms for automated defect interpretation, to improve the speed and
consistency of sewer CCTV inspections. The development, calibration, and
testing of the algorithms in this study followed an iterative approach that
began with the development of a defect classification system using a 5-layer
convolutional neural network (CNN) and evolved into a two-step defect
classification and localization framework, which combines a the ResNet34 CNN
and Faster R-CNN object detection model. This study also demonstrates the use
of a feature visualization technique, called class activation mapping (CAM), as
a diagnostic tool to improve the accuracy of CNNs in defect classification
tasks—thereby representing a crucial first step in using CNN interpretation
techniques to develop improved models for sewer defect identification. </p>
<p> </p>
<p>Extending upon the development of automated defect
interpretation algorithms, the second objective of this study attempts to
facilitate autonomous navigation of sewer CCTV robots. To overcome Global
Positioning System (GPS) signal unavailability inside underground pipes, this
study developed a vision-based algorithm that combines deep learning-based
object detection with optical flow for estimating the orientation of sewer CCTV
cameras. This algorithm can enable inspection robots to estimate their
trajectories and make corrective actions while autonomously traversing pipes.
Hence, considered together, the first two objectives of this study pave the way for future
inspection technologies that combine automated defect interpretation with
autonomous navigation of sewer CCTV robots.</p>
<p> </p>
<p>The third and final objective of this study seeks to develop
a novel methodology that incorporates spatial information about defects (such
as their locations, densities, and co-occurrence characteristics) when
assessing sewer deterioration. A methodology called Defect Cluster Analysis
(DCA) was developed in order to mine sewer inspection reports and identify pipe
segments that contain clusters of defects (i.e., multiple defects in
proximity). Additionally, an approach to mine co-occurrence characteristics
among defects is also introduced (i.e., identification of defects which occur
frequently together). Together the two approaches (i.e., DCA and co-occurrence
mining) address a key limitation of existing deterioration modeling approaches
(i.e., the lack of consideration to spatial information about defects)—thereby
leading to the generation of new insights into pipeline rehabilitation
decision-making. </p>
<p> </p>
<p>The algorithms and approaches presented in this dissertation
have the potential to improve the speed, accuracy, and consistency of assessing
sewer pipeline deterioration, leading to better prioritization strategies for
maintenance, repair, and rehabilitation. The automated defect interpretation
algorithms proposed in this study can be used to assign the subjective and
error-prone task of defect identification to computer processes, thereby
enabling human operators to focus on decision-making aspects, such as deciding
whether to repair or rehabilitate a pipe. Automated interpretation of sewer
CCTV videos could also facilitate re-evaluation of historical sewer inspection
videos, which would be infeasible if performed manually. The information
gleaned from re-evaluating these videos could generate insights into pipe
deterioration, leading to improved deterioration models. The algorithms for
autonomous navigation could enable the development of completely autonomous
inspection platforms that utilize unmanned aerial vehicles (UAVs) or similar
technologies to facilitate rapid assessment of sewers. Furthermore, these
technologies could be integrated into wireless sensor networks, paving the way
for real-time condition monitoring of sewer infrastructure. The DCA approach
could be used as a diagnostic tool to identify specific sections in a pipeline
system that have a high propensity for failure due to the existence of multiple
defects in proximity. When combined with contextual information (e.g., soil
properties, water table levels, and presence of large trees), DCA could provide
insights about the likelihood of void formation due to sand infiltration. The
DCA approach could also be used to periodically determine how the distribution
of defects and their clustering progresses with time and when examined
alongside contextual data (e.g., soil properties, water table levels, presence
of trees) could reveal trends in pipeline deterioration. </p>
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Analyse du transport solide en réseau d’assainissement unitaire par temps de pluie : exploitation de données acquises par les observatoires français en hydrologie urbaine / Analysis of solid transport in combined sewer network during wet weather : exploitation of data acquired by the French observatories in urban hydrologyHannouche, Ali 23 November 2012 (has links)
Cette thèse valorise les données de mesure en continu de pluie de débit et de turbidité, ainsi que les bases de donnée de résultat d'analyse et les connaissances acquises dans le cadre des trois observatoires français en hydrologie urbaine, OPUR-Paris, OTHU-Lyon et ONEVU Nantes, pour valider et améliorer les connaissances sur les flux et les sources de particules vectrices de contaminants, en réseaux d'assainissement unitaire. Les données provenant de 6 sites expérimentaux drainés par un réseau d'assainissement unitaire ont été exploitées : Marais, Quais et Clichy à Paris, Cordon Bleu et Saint-Mihiel à Nantes et Écully à Lyon, avec sur chaque site des bases de données de longue durée qui ont permis des études statistiques sur des échantillons de plusieurs dizaines d'événements pluvieux et de journées de temps sec. Cette thèse a permis : 1- d'évaluer la représentativité de la turbidité pour analyser du transport solide en réseau ; 2- d'analyser et de modéliser statistiquement les concentrations et les masses de particules à l'échelle événementielle ; 3- d'étudier la dynamique des flux et des concentrations à l'échelle intra-événementielle. Les résultats obtenus indiquent d'une part, que la turbidité permet de décrire les dynamiques intra-événementielles des flux et des concentrations à condition d'exprimer ceux-ci sous forme relative, normalisée par les valeurs moyennes événementielles. En revanche, ces valeurs événementielles sont attachées par des erreurs systématiques non négligeables induites par les variations inter-événementielles de la relation MES-Turbidité (intervalle de confiance de l'ordre de 30% de la moyenne). Ils confirment d'autre part que la contribution des dépôts aux flux de temps de pluie est importante mais variable (entre 20 et 80% de la masse à l'exutoire selon l'événement), y compris sur un site réputé exempt de dépôts (grossiers). Autrement dit, les problématiques d'ensablement et de pollution de temps de pluie ne sont pas nécessairement liées. L'autre contribution majeure est celle des eaux usées « de temps sec ». De plus, ils nous ont permis de progresser dans la compréhension des phénomènes de décalage temporel entre hydrogramme et pollutogramme et d'effet piston / This thesis exploits continuous measurement of rainfall, discharge and turbidity data and the knowledge acquired by three French observatories in urban hydrology, OPUR-Paris, OTHU Lyon and ONEVU-Nantes, to validate and improve knowledge on suspended solids discharges and sources of particles, which are major vectors of contaminants in combined sewer systems. Data from six experimental sites served by a combined sewer system were used: Marais, Quais and Clichy in Paris, Cordon Bleu and Saint-Mihiel in Nantes and Ecully in Lyon. At each site, a long duration databases enabled statistical studies on samples of several tens of rainfall events and dry weather days. This thesis allowed: 1-to assess the representativeness of turbidity to analyze sediments transport in network; 2-to analyze and model concentrations and masses of particles at the scale of rain events; 3-to study the dynamics of fluxes and concentrations at intra-event scale. Results show that turbidity can describe the dynamics of intra-event fluxes and concentrations provided these are expressed in a relative form, normalized by the event mean values. However, these mean values are attached by significant systematic errors induced by variations of the inter-event TSS-turbidity relationship (95% confidence interval about 30% of average). The contribution of sewer deposits to wet weather suspended solids discharges is important but variable (between 20 and 80% of the mass at the outlet depending on the event), including for a site allegedly free of (coarse) sewer deposits. In other words, the problems of silting and contribution from deposits to wet weather pollution are not necessarily related. The other major contribution is from “dry weather” wastewater. In addition, they we made some progress in understanding the lag-time phenomena between hydrograph and pollutograph and the piston effect
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