Journal articles: 'Sewer design Mathematical models'

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Duque, Natalia, Daniel Duque, Andrés Aguilar, and Juan Saldarriaga. "Sewer Network Layout Selection and Hydraulic Design Using a Mathematical Optimization Framework." Water 12, no. 12 (November 27, 2020): 3337. http://dx.doi.org/10.3390/w12123337.

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This paper proposes an iterative mathematical optimization framework to solve the layout and hydraulic design problems of sewer networks. The layout selection model determines the flow rate and direction per pipe using mixed-integer programming, which results in a tree-like structured network. This network layout parametrizes a second model that determines hydraulic features including the diameter and the upstream and downstream invert elevations of pipes using a shortest path algorithm. These models are embedded in an iterative scheme that refines a cost function approximation for the first model upon learning the actual design cost from the second model. The framework was successfully tested on two sewer network benchmarks from the literature and a real sewer network located in Bogotá, Colombia, that is proposed as a new instance. For both benchmarks, the proposed methodology found a better solution with up to 42% cost reduction compared to the best methodologies reported in the literature. These are near-optimal solutions with respect to construction cost that satisfy all hydraulic and pipe connectivity constraints of a sewer system.

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Csicsaiová, R., J. Hrudka, I. Marko, and Š. Stanko. "Application of mathematical models in design and assessment of sewer network facilities." IOP Conference Series: Materials Science and Engineering 867 (October 9, 2020): 012005. http://dx.doi.org/10.1088/1757-899x/867/1/012005.

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Wittmanová, R., I. Makro, J. Hrudka, M. Šutús, and Š. Stanko. "Modelling of Stormwater runoff and Wastewater Flow in the Sewer Network." IOP Conference Series: Materials Science and Engineering 1252, no. 1 (September 1, 2022): 012068. http://dx.doi.org/10.1088/1757-899x/1252/1/012068.

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Abstract The purpose of mathematical modelling of sewer networks is mainly to assess the hydraulic capacity and monitor its behaviour under different conditions to predict the future state. Sewerage network models are also part of the design process. Their advantage is the possibility of simulating the future state of the network and the precipitation and runoff process in the context of climate change. With the help of simulations, it is possible to anticipate future conditions in urban catchments and thus effectively design new networks. The aim of this paper is to summarize mathematical simulation models that are used to model sewer networks.

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Gall, B., D. Averill, and D. Weatherbe. "Modelling, Design and Optimization of a Combined Sewer Overflow Treatment System." Water Quality Research Journal 32, no. 1 (February 1, 1997): 139–54. http://dx.doi.org/10.2166/wqrj.1997.010.

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Abstract A process modelling and simulation program is being developed as part of a pilot-scale study of satellite treatment options for the control of combined sewer overflows (CSOs). The initial objectives are (1) the development of mathematical models for satellite wastewater treatment processes; (2) the implementation of these models in a computer simulator; and 3) the application of these models to provide a preliminary design of a full-scale CSO treatment facility that will satisfy the local regulatory agency. Results to date show that the models and simulation algorithms constitute a useful planning level tool for investigating CSO control options. The results also indicate the direction of further model development work.

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Voronov, Yuri P. "DIGITAL TERRAIN MODELS IN SIBERIAN CITIES AND UTILITY NETWORKS DESIGN." Interexpo GEO-Siberia 3, no. 1 (May 21, 2021): 152–61. http://dx.doi.org/10.33764/2618-981x-2021-3-1-152-161.

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The article considers one of the important directions of innovative technologies in the urban economy, application of digital terrain models in the design, development and operation of utility networks. The author considers the five tasks of using the digital model sequentially: ) development of a digital terrain model, 2) allocation of watersheds and facies, 3) plotting contours (ridges) for all facies, 4) two-level modeling of surface runoff and storm sewer, 5) solving practical problems of determining silting zones and optimizing snow removal. The original principle proposed in the article is a multi-funnel model of surface runoff, in which each facies (local catchment) is replaced by an equivalent inclined funnel. This greatly simplifies the calculations, and also allows you to combine mathematical modeling with physical modeling.

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Head, P. C., D. H. Crawshaw, P. Dempsey, and C. J. Hutchings. "Bathing in the Rain - The Use of Mathematical Models for Storm Water Management to Achieve Bathing Water Quality (The Fylde Coast-NW England)." Water Science and Technology 25, no. 12 (June 1, 1992): 59–68. http://dx.doi.org/10.2166/wst.1992.0337.

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One of the major problems in trying to design wastewater treatment schemes to protect bathing water for coastal communities with combined sewerage systems, is to ensure that discharges of storm water do not prejudice compliance with the requirements of the EC Bathing Water Directive. In order to develop an appropriate storm water management strategy for the Fylde coast it was necessary to integrate a number of mathematical models simulating the hydraulic behaviour of the sewerage system and the dispersion of discharges in the receiving waters. From the sewerage system modelling it was apparent that frequent discharges of storm water to the bathing waters could only be avoided by the provision of considerable additional storage in the system. By means of a suitably calibrated simplified sewer model it was possible to investigate the volumes of storm water generated by a 15 year record of local rainfall when different amounts of extra storage and different pumping regimes were employed. The results from these investigations were used to determine the probable concentrations of faecal bacteria in the coastal waters for each of the 15 bathing seasons and determine the percentage of time for which faecal coliform concentrations exceeded the Bathing Water directive standards for the model grid cells representing the identified bathing waters. As a result of the extensive integrated modelling programme for the Fylde coast it has been possible to design a base flow and storm water management system which should maximize the flow passed forward for treatment whilst also ensuring that there is just sufficient storage to ensure protection of the towns from flooding and the compliance of the beaches with the Bathing Water Directive standards.

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Mietzel, T., K. Klepiszewski, and G. Weiss. "Development and verification of a general approach to describe the efficiency of vortex separators in combined sewer systems." Water Science and Technology 55, no. 4 (February 1, 2007): 165–73. http://dx.doi.org/10.2166/wst.2007.106.

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The water framework directive (CEC, 2000) asks for cost-effective measures for achieving good ecological conditions in receiving waters. Because of low operation costs and good pollutant removal efficiency, vortex separators (VS) are an attractive alternative to traditional stormwater tanks. The German design standard for CSO structures, ATV-A 128 (1992), demands long-term pollution load simulations. Today's simulation software, however, considers the removal processes in CSO structures either very rudimentarily or not at all. The higher pollutant removal efficiency of a structure like a VS cannot be taken into account. This might be one reason why VS are used still comparatively scarcely. A mathematical model describing the removal efficiency could increase the acceptance of VS. Several functions describing the removal efficiency have been derived from model tests or large-scale studies within the last few years. Within this paper, the data from three large-scale studies are used to verify the general applicability of one steady-state and one dynamic approach. The results show that the complex processes involved with CSO facilities and the large error related to monitoring make the validation of models a difficult task. Anyhow, especially the dynamic approach was applicable at all considered facilities.

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Telyatnikova, Anna, Sviatoslav Fedorov, Iurii Stolbikhin, and Elena Korneeva. "Prediction of hydrogen sulfide emission from an energy dissipation chamber and assessment of its distribution in the ambient air." E3S Web of Conferences 140 (2019): 06001. http://dx.doi.org/10.1051/e3sconf/201914006001.

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Wastewater transport in sewer networks contributes to the formation and emission of fetid and toxic sewage gases into the environment, one of which is hydrogen sulfide. The emission of gases can have a significant impact on the environment and health of maintenance workers and city residents. The object of the research is the study of the process of hydrogen sulfide emission in the energy dissipation chamber (EDC). The method of two-stage mathematical modeling in the program of finite element analysis ANSYS CFX is applied for the research. Two models have been created, the first one simulates the internal space of the EDC structure itself, and the second one simulates the EDC manhole and the volume of the surrounding air next to it. Mathematical dependences of hydrogen sulfide concentration change at three sections inside the structure are obtained for incoming wastewater flow velocities V = 1 m/s, 1.5 m/s and 2 m/s. The critical flow velocities at which the maximum single threshold limit value will exceed 1 m/s and the threshold limit value of the working area will exceed 1.52 m/s are determined. The methodology for solving the problem of assessing the impact of the EDC object on the environment is formed. The results of the study can be applied in the design of structures for a preliminary assessment and prediction of the impact of a wastewater facility, as well as the selection of the most favorable hydraulic regime.

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Abdulmazhidov, Kh A. "Dependence of the performance of the reclaiming sewer cleaner with rigid guides from interchangeable bucket tools capabilities." Vegetable crops of Russia, no. 6 (December 10, 2022): 125–29. http://dx.doi.org/10.18619/2072-9146-2022-6-125-129.

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Relevance. Cleaning of reclamation channels is a very relevant event. The need to clean the canals and maintain them in working condition becomes obvious during the flood period, when it is necessary to remove excess water. The paper presents mathematical models for determining the performance of the PP-303 canal cleaner, a feature of which is the rectilinear movement of the bucket on rigid guides along the bottom along the axis of the canal to be cleaned.Methods. The article is formed on the basis of experimental research methods. The research was carried out based on experimental and calculated data. A network of drainage canals of the drainage system was taken as the research object, and the working equipment of the canal cleaner was taken as the research subject. Performance, which is the amount of products produced by the machine per unit of time, can be of three types (theoretical, technical, and operational) and can be determined with consideration of the design parameters of the working equipment. During the operation of trench cutting machines, their performance directly depends on the main parameter, namely, the depth of the canal being built; in the case of canal cleaning with canal cleaners, this parameter cannot be considered as the main one. This is due to the fact that siltation and sediments accumulating on the bottom and slopes of the canals during the operation of the reclamation system are extremely unevenly distributed along the length of the canal. The highest concentration and amount of sediments and siltation is observed mainly at the mouth of the canals, the junctions of canals of different levels, and the junctions of the drainage with the drainage canal. In this case, the most significant parameter is the thickness of the chips removed from the bottom and slopes of the canal by the bucket.Results. The results of the research showed that the performance of the channel cleaner, as a batch machine, is influenced by the very design of the working equipment, the main element of which is a bucket capable of moving in a straight line along rigid guides at different speeds. With obvious high values of the performance of continuous channel cleaning machines, it can be concluded that the channel cleaner RR-303 showed high values of technical and operational characteristics, mainly due to the use of a trapezoidal profile bucket.

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Dean, Justin, Evan Goldberg, and Franziska Michor. "Designing optimal allocations for cancer screening using queuing network models." PLOS Computational Biology 18, no. 5 (May 27, 2022): e1010179. http://dx.doi.org/10.1371/journal.pcbi.1010179.

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Cancer is one of the leading causes of death, but mortality can be reduced by detecting tumors earlier so that treatment is initiated at a less aggressive stage. The tradeoff between costs associated with screening and its benefit makes the decision of whom to screen and when a challenge. To enable comparisons across screening strategies for any cancer type, we demonstrate a mathematical modeling platform based on the theory of queuing networks designed for quantifying the benefits of screening strategies. Our methodology can be used to design optimal screening protocols and to estimate their benefits for specific patient populations. Our method is amenable to exact analysis, thus circumventing the need for simulations, and is capable of exactly quantifying outcomes given variability in the age of diagnosis, rate of progression, and screening sensitivity and intervention outcomes. We demonstrate the power of this methodology by applying it to data from the Surveillance, Epidemiology and End Results (SEER) program. Our approach estimates the benefits that various novel screening programs would confer to different patient populations, thus enabling us to formulate an optimal screening allocation and quantify its potential effects for any cancer type and intervention.

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Plósz, Benedek Gy, Helge Liltved, and Harsha Ratnaweera. "Climate change impacts on activated sludge wastewater treatment: a case study from Norway." Water Science and Technology 60, no. 2 (July 1, 2009): 533–41. http://dx.doi.org/10.2166/wst.2009.386.

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We present an investigation on climate change effects on a wastewater treatment system that receive sewage collected in a combined sewer system in Oslo, Norway, during winter operation. Results obtained, by contrasting meteorological data with sewage data, show that wastewater treatment plant (WWTP) influent flow rates are significantly increased during temporary snow melting periods above a critical daily air mean temperature of approx. −1.5°C degree (TCrit) identified in the area. In order to assess melting patterns, the number of days above and below TCrit was assessed, and the annual number of melting periods was additionally evaluated using meteorological data obtained in the last decade. A striking thing about the daily air temperature pattern is that, despite the progressively warmer winter temperatures in the last decade, an increasing number of days with temperatures below −1.5°C could be observed. The frequency of melting periods is shown to increase in wintertime, and it is identified as an additional climate change related factor in the Oslo region. We demonstrate that these impacts can deteriorate the WWTP operation through progressively increasing the relative frequencies of very high influent flow rate and of the very low influent sewage temperature. Such climate change related effects on sewage treatment processes can be characterised as shock-conditions, i.e. significant changes in a system’s boundary conditions, occurring in a relatively short period of time. In the six year period examined, biological nitrogen removal and secondary clarification processes are shown to be significantly affected by the climate factors. A striking thing about using the state-of-the-art mathematical models of wastewater treatment processes in decision support systems is their inability of describing, and thus predicting the effects of such shock-loading events, as they have not been studied so far. Adaptation and optimisation of process models, also for use in design, optimisation as well as in real-time automation and process control schemes, are thus critical to meet the challenges of climatic changes in the future.

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Head, P. C., D. H. Crawshaw, and S. K. Rasaratnam. "Fylde Coast Bathing Water Improvements – Storm Water Management for Compliance with Bathing Water Directive." Water Science and Technology 22, no. 10-11 (October 1, 1990): 223–30. http://dx.doi.org/10.2166/wst.1990.0308.

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As part of the investigations to determine the most appropriate scheme to bring the Fylde Coast bathing waters up to the quality required by the EC Bathing Water Directive, mathematical models have been used to examine the hydraulic behaviour of the sewerage system and the subsequent dispersion of effluent in the receiving waters. The discharge characteristics of the existing sewerage systems were examined by means of an extensive WASSP model, validated by means of flow measurements gathered from critical points of the sewer network. This model was then used, in conjunction with a time series rainfall record for the area, to investigate the effect of the intensity and duration of rainfall events on the volume of storm sewage to be discharged. Because the area is drained by a combined system, the management of storm water is of utmost importance and the output of the WASSP model was used to determine the input to the coastal dispersion model for rainfall events. A preliminary examination of the possible sites for sewage treatment works and sea outfalls, for sewage and storm water, suggested four possible schemes involving either inland treatment, marine treatment or a combination of the two. All options required the discharge of storm water to the sea. Extensive dispersion modelling was carried out to examine the probable effects of various storm-water management strategies on bacterial concentrations in the receiving waters. From this it was apparent that storage of storm flows, with controlled discharge, at the state of tide when environmental impact would be minimal, was required to achieve compliance with the provisions of the Directive. By integrating the WASSP modelling of various base-flow and storm-water storage options with dispersion modelling, it was possible to establish appropriate design criteria.

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Rodríguez, J. P., S. Achleitner, M. Möderl, W. Rauch, Č. Maksimović, N. McIntyre, M. A. Díaz-Granados, and M. S. Rodríguez. "Sediment and pollutant load modelling using an integrated urban drainage modelling toolbox: an application of City Drain." Water Science and Technology 61, no. 9 (May 1, 2010): 2273–82. http://dx.doi.org/10.2166/wst.2010.139.

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Numerical and computational modelling of flow and pollutant dynamics in urban drainage systems is becoming more and more integral to planning and design. The main aim of integrated flow and pollutant models is to quantify the efficiency of different measures at reducing the amount of pollutants discharged into receiving water bodies and minimise the consequent negative water quality impact. The open source toolbox CITY DRAIN developed in the Matlab/Simulink© environment, which was designed for integrated modelling of urban drainage systems, is used in this work. The goal in this study was to implement and test computational routines for representing sediment and pollutant loads in order to evaluate catchment surface pollution. Tested models estimate the accumulation, erosion and transport of pollutants—aggregately—on urban surfaces and in sewers. The toolbox now includes mathematical formulations for accumulation of pollutants during dry weather period and their wash-off during rainfall events. The experimental data acquired in a previous research project carried out by the Environmental Engineering Research Centre (CIIA) at the Universidad de los Andes in Bogotá (Colombia) was used for the calibration of the models. Different numerical approaches were tested for their ability to calibrate to the sediment transport conditions. Initial results indicate, when there is more than one peak during the rainfall event duration, wash-off processes probably can be better represented using a model based on the flow instead of the rainfall intensity. Additionally, it was observed that using more detailed models (compared with an instantaneous approach) for representing pollutant accumulation do not necessarily lead to better results.

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Mourato, S., J. Matos, M. Almeida, and T. Hvitved-Jacobsen. "Modelling in-sewer pollutant degradation processes in the Costa do Estoril sewer system." Water Science and Technology 47, no. 4 (February 1, 2003): 93–100. http://dx.doi.org/10.2166/wst.2003.0229.

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Characteristics of wastewater vary during transportation through sewer systems as a result of a number of processes. Under aerobic conditions, in long sewer systems, the reduction of the BOD or COD may be similar to the reduction obtained in conventional primary settling tanks. The mathematical model that was developed is based on a number of different existing models: the ASM n. 1 and ASM n. 2 models, the AEROSEPT model and the WATS model. The model also includes a prediction of reaeration at falls. The module of the anoxic conditions was adapted from the ASM n. 2 model. This module is a first attempt to model the degradation of organic matter in sewer systems under anoxic conditions. The mathematical model was applied to the Costa do Estoril intercepting sewer, and the obtained results are discussed taken into account the experimental data that was collected during a three-month period. Average removals of dissolved COD over 20% have been obtained. In the paper special emphasis is given to the importance of the performance of the Costa do Estoril sewer system as a biological reactor.

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Marsalek, J., T. O. Barnwell, W. Geiger, M. Grottker, W. C. Huber, A. J. Saul, W. Schilling, and H. C. Torno. "Urban Drainage Systems: Design and Operation." Water Science and Technology 27, no. 12 (June 1, 1993): 31–70. http://dx.doi.org/10.2166/wst.1993.0291.

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Design and operation of urban drainage systems are addressed in the context of the urban water system comprising drainage, sewage treatment plants and receiving waters. The planning and design of storm sewers are reviewed with reference to planning objectives, design objectives, flows and pollutant loads, sewer system structures and urban runoff control and treatment. The discussion of combined sewers focuses on hydraulic design of combined sewer systems, including combined sewer overflow (CSO) structures, and the use of CSO structures and storage in control of CSOs. The section on operation of sewer systems focuses on real time control, its feasibility, planning, design, operation and applications. Sewer system planning and design are generally conducted using computer modelling tools and procedures which are reviewed in the last section. A brief listing of selected models focuses on internationally used models. Finally, it was concluded that further improvements in environmental and ecological protection of urban waters is feasible only by consideration of urban drainage systems in conjunctions with sewage treatment and water quality in the receiving waters.

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Kutzner, R., H. Brombach, and W. F. Geiger. "Sewer solids separation by sedimentation – the problem of modeling, validation and transferability." Water Science and Technology 55, no. 4 (February 1, 2007): 113–23. http://dx.doi.org/10.2166/wst.2007.101.

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Sedimentation of sewer solids in tanks, ponds and similar devices is the most relevant process for the treatment of stormwater and combined sewer overflows in urban collecting systems. In the past a lot of research work was done to develop deterministic models for the description of this separation process. But these modern models are not commonly accepted in Germany until today. Water Authorities are sceptical with regard to model validation and transferability. Within this paper it is checked whether this scepticism is reasonable. A framework-proposal for the validation of mathematical models with zero or one dimensional spatial resolution for particle separation processes for stormwater and combined sewer overflow treatment is presented. This proposal was applied to publications of repute on sewer solids separation by sedimentation. The result was that none of the investigated models described in literature passed the validation entirely. There is an urgent need for future research in sewer solids sedimentation and remobilization!

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Kalinin, Anatoliy Vladimirovich. "CALCULATION OF FRICTION LOSSES COEFFICIENT IN COMBINED SEWER PIPS." Urban construction and architecture 4, no. 1 (March 15, 2014): 58–61. http://dx.doi.org/10.17673/vestnik.2014.01.10.

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A result of experimental studies of coeffi cient of hydraulic friction on depending on the form of bott om microrelief is submitt ed. The comparative analysis of calculation of friction losses coeffi cient with the results of measurements made in the combined sewer pips in France is given. Further research in this area will improve the existing mathematical models of water movement in the storm sewer networks.

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Ayub, Nabende, Twaibu Semwogerere, and Richard O. Awichi. "Mathematical Modelling of Sewage Overflow Through Pipe-Manhole Drainage Sewer Systems Using CFD: A Case of Mbale City, Eastern Uganda." East African Journal of Engineering 2, no. 1 (November 23, 2020): 33–45. http://dx.doi.org/10.37284/eaje.2.1.239.

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The major objective of this study was to design a model to optimize sewage flow through pipe-manhole drainage systems using Computational Fluid Dynamics (CFD). Multi-phase flows like two-phase flow in transport pipes is a common occurrence in many industrial applications such as sewage, water, oil, gas transportation and power generation. Accurate prediction of fluid velocity and pressure drop is of utmost importance to ensure effective design and operation of fluid transport systems. Numerical simulations were performed at different pipe inclinations and fluid flow velocities. A two-dimensional pipe of 0.5 m in diameter and 20 m long was used with a Standard k−ε turbulence and the volume of fraction (VOF) free surface model to solve the turbulent mixture flow of air and water. The CFD approach is based on the Navier-Stokes equations. Results show that the flow pattern behaviour and numerical values of liquid velocities and pressure drop compare reasonably well. It is concluded that the most effective way to optimize a sewer network system in order to minimize the overflows through Pipe-manhole drainage system for Mbale Municipality conditions is by considering minimum and maximum sewer velocities in the range 0.67 ms−1 to 5.5 ms−1 respectively, sewer diameters, slope gradients for optimal sewer design and expanding the number of sewer network connections of household, municipal and industries.

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THOMPSON, G. "Mathematical Models and Engineering Design." Water and Environment Journal 7, no. 1 (February 1993): 18–23. http://dx.doi.org/10.1111/j.1747-6593.1993.tb00805.x.

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Kleijwegt, Rob A. "On the Prediction of Sediment Transport in Sewers with Deposits." Water Science and Technology 27, no. 5-6 (March 1, 1993): 69–80. http://dx.doi.org/10.2166/wst.1993.0487.

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There is a need for models to predict the negative effects of sewer deposits in order to improve design, maintenance and operation of sewerage systems. The lack of success of deterministic sewer sediment models in the past is caused by a lack of basic knowledge, which causes unknown uncertainties in the model's results. The basic knowledge about non-cohesive sediment transport has been studied with laboratory experiments. This has resulted in an understanding of the non-cohesive sewer sediment transport and the related subjects of bed shear stress, incipient motion, bed forms and flow resistance. This understanding can be used in the development of deterministic models for sewer systems. However, the next objective will be to develop probabilistic models.

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Verbanck, Michel A. "Assessment of sediment behaviour in a cunette-shaped sewer section." Water Science and Technology 33, no. 9 (April 1, 1996): 49–59. http://dx.doi.org/10.2166/wst.1996.0174.

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The accumulation of deposits in sewers causes widespread concerns of either operational or environmental nature. It is believed that a number of sediment-related nuisances can substantially be controlled in adapting the characteristics of sewer pipes as a function of local constraints and circumstances. In particular, key design parameters such as cross-section shape or hydraulic roughness of inner walls are currently selected basing more on empiricism and intuition than on full knowledge of the sediment transport driving processes. A valid track for optimization of these parameters is to run mathematical simulations of the sediment transport behaviour under varying design scenarios. This option, however, supposes that a robust mathematical procedure to compute sediment transport capacity in sewers is available, embracing all primary physical factors of influence. Starting from a theoretical description of shear turbulence suggested by Bagnold (1966), a suspension formula is developed dedicated to the specific sewer flow properties. Applying this formula to the case of a main sewer presenting a composite cross-section allows to illustrate how geometrical discontinuities influence sediment transport characteristics in real conduits.

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Alfaisal, Faisal M., and Larry W. Mays. "Optimization Models for Layout and Pipe Design for Storm Sewer Systems." Water Resources Management 35, no. 14 (September 29, 2021): 4841–54. http://dx.doi.org/10.1007/s11269-021-02958-5.

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Han, Li. "Mathematical Models for Logical Design Methodology." International Journal of Design Education 16, no. 1 (2021): 105–15. http://dx.doi.org/10.18848/2325-128x/cgp/v16i01/105-115.

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Han, Li. "Mathematical Models for Logical Design Methodology." International Journal of Design Education 16, no. 1 (2021): 105–15. http://dx.doi.org/10.18848/2325-128x/cgp/v16i01/105-115.

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Mukhacheva, Elita A., and Tatiana A. Panyukova. "Mathematical Models of Cutting Process Design." IFAC Proceedings Volumes 42, no. 4 (2009): 1085–90. http://dx.doi.org/10.3182/20090603-3-ru-2001.0338.

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Fronteau, C., W. Bauwens, and P. A. Vanrolleghem. "Integrated modelling: comparison of state variables, processes and parameters in sewer and wastewater treatment plant models." Water Science and Technology 36, no. 5 (September 1, 1997): 373–80. http://dx.doi.org/10.2166/wst.1997.0235.

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All the parts of an urban drainage system, i.e. the sewer system, the wastewater treatment plant (WWTP) and the river, should be integrated into one single model to assess the performance of the overall system and for the development of design and control strategies assisting in its sustainable and cost effective management. Existing models for the individual components of the system have to be merged in order to develop the integrated tool. One of the problems arising from this methodology is the incompatibility of state variables, processes and parameters used in the different modelling approaches. Optimisation of an urban drainage system, and of the wastewater treatment process in particular, requires a good knowledge of the wastewater composition. As important transformations take place between the emission from the household and the arrival at the treatment facility, sewer models should include these transformations in the sewer system. At present, however, research is still needed in order to increase our knowledge of these in-sewer processes. A comparison of the state variables, processes and parameters has been carried out in both sewer models (SMs) and activated sludge models (ASMs). An ASM approach is used for the description of reactions in sewer models. However, a difference is found in the expression for organic material (expressed in terms of BOD) and heterotrophic biomass is absent as a state variable, resulting in differences in processes and parameters. Reconciliation of both the models seems worthwhile and a preliminary solution is suggested in this paper.

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Hansen, O. B., C. Jacobsen, P. Harremoës, and P. Skat Nielsen. "Stormwater Loading of Greater Copenhagen Sewage Treatment Plants." Water Science and Technology 27, no. 5-6 (March 1, 1993): 49–59. http://dx.doi.org/10.2166/wst.1993.0485.

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The study presented in this paper deals with the computation of the increased hydraulic loading of the treatment plants in the Greater Copenhagen area due to the installation of more storage capacity in the combined sewer system in the future. A mathematical model is set up for the entire sewer catchment and predictions of future increased hydraulic loadings are made for various development scenarios. The computed inflow conditions are presented on a statistical form. The results show a significant increase in the hydraulic loading of the plants due to increased storage volume in the sewer system. The computed inflow statistics are used in the design of the treatment plants to ensure proper plant performance during prolonged periods with full hydraulic loading due to storm water.

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Mair, M., R. Sitzenfrei, M. Kleidorfer, M. Möderl, and W. Rauch. "GIS-based applications of sensitivity analysis for sewer models." Water Science and Technology 65, no. 7 (April 1, 2012): 1215–22. http://dx.doi.org/10.2166/wst.2012.954.

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Sensitivity analysis (SA) evaluates the impact of changes in model parameters on model predictions. Such an analysis is commonly used when developing or applying environmental models to improve the understanding of underlying system behaviours and the impact and interactions of model parameters. The novelty of this paper is a geo-referenced visualization of sensitivity indices for model parameters in a combined sewer model using geographic information system (GIS) software. The result is a collection of maps for each analysis, where sensitivity indices (calculated for model parameters of interest) are illustrated according to a predefined symbology. In this paper, four types of maps (an uncertainty map, calibration map, vulnerability map, and design map) are created for an example case study. This article highlights the advantages and limitations of GIS-based SA of sewer models. The conclusion shows that for all analyzed applications, GIS-based SA is useful for analyzing, discussing and interpreting the model parameter sensitivity and its spatial dimension. The method can lead to a comprehensive view of the sewer system.

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Stirrup, M., Z. Vitasovic, and E. Strand. "Real-Time Control of Combined Sewer Overflows in Hamilton-Wentworth Region." Water Quality Research Journal 32, no. 1 (February 1, 1997): 155–68. http://dx.doi.org/10.2166/wqrj.1997.011.

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Abstract The Regional Municipality of Hamilton-Wentworth operates and maintains a large combined sewer system in the Great Lakes basin. During dry weather and small storm events, two large interceptor sewers convey all sanitary and storm flows to the Woodward Avenue wastewater treatment plant. Larger rainfall events, specifically high intensity summer thunderstorms, generate flows which exceed the design capacity of the sanitary interceptors and result in combined sewer overflows to Hamilton Harbour and Cootes Paradise, which ultimately discharge to Lake Ontario. The Region is implementing a comprehensive program for reducing the pollution caused by these overflows. This program includes the construction of several off-line detention storage facilities and the implementation of a real-time control system for combined sewer overflow reduction. Real-time control will enable maximum utilization of the storage available within the combined sewer network and help reduce the frequency and volume of combined sewer overflows. New hydrologic and hydraulic simulation models have been specially developed for this project to help identify, test and implement optimal real-time control strategies. This paper discusses some of the more important aspects related to the design and implementation of the Region’s real-time control system, and focuses mainly on the development of these hydrologic and hydraulic simulation models.

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Primin, Oleg, Andrey Ten, and Daria Khudyakova. "Hydraulic calculations of storm sewer networks." E3S Web of Conferences 163 (2020): 03012. http://dx.doi.org/10.1051/e3sconf/202016303012.

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Surface run-off (SR) produced on the territory of cities and other settlement as a result of atmospheric precipitation is an intensive source of the technogenic pollution of environment, including the waterbodies. In accordance with the existing legislation of the Russian Federation, SR requires organized disposal and treatment according to the standards of regulatory documents. In this article we analyze the European document BS EN 752:2017 with regard to determining the flow-rates of surface (storm-water) run-off, and the calculations are made by the authors, which demonstrate that the application of foreign software products is impossible in Russia, due to the differences between the existing Russian regulatory and methodological documents and the European standards. Nevertheless, for the development of electronic models of hydraulic calculations for a storm-water drainage network, the mathematical relationship, which most adequately characterizes the type of surface run-off hydrograph most frequent for the territory of the Russian Federation as a result of atmospheric precipitation, was found. The relevant algorithm of the hydraulic calculation of storm-water drainage networks was also developed.

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Kalyakulin, S. Yu, E. V. Mitin, and S. P. Sul’din. "Classification of Mathematical Models for Process Design." Russian Engineering Research 41, no. 11 (November 2021): 1045–48. http://dx.doi.org/10.3103/s1068798x21110137.

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Staribratov, Ivaylo, and Nikol Manolova. "Application of Mathematical Models in Graphic Design." Mathematics and Informatics LXV, no. 1 (February 28, 2022): 72–81. http://dx.doi.org/10.53656/math2022-1-5-app.

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The article shares the practical experience in creating graphic design in the implementation of projects in the field of applied information technology. The creation of digital art is largely based on mathematical models and concepts that give a good perception of graphics, and it is scientifically justified. The STEAM approach is considered with the idea of the transdisciplinary level of integration between mathematics, graphic design and production practice in student education. For the development of projects like logo design, magazine cover and others, we use software specialized in the field of graphic design and computer graphics. For the realization of the considered projects, among which there are also awarded ones, we use CorelDRAW, Adobe InDesign and Desmos.

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Sonderman, David, and Philip G. Abrahamson. "Radiotherapy Treatment Design Using Mathematical Programming Models." Operations Research 33, no. 4 (August 1985): 705–25. http://dx.doi.org/10.1287/opre.33.4.705.

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Khan, Faisal I., and S. A. Abbasi. "Effective design of greenbelts using mathematical models." Journal of Hazardous Materials 81, no. 1-2 (January 2001): 33–65. http://dx.doi.org/10.1016/s0304-3894(00)00288-0.

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Goncharenko, Dmitriy, Ihor Shumakov, Olha Starkova, Alevtyna Aleinikova, and Revaz Mikautadze. "Methodological and computer-based support for choosing underground utility networks renovation method." MATEC Web of Conferences 230 (2018): 02010. http://dx.doi.org/10.1051/matecconf/201823002010.

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The article is devoted to the methodological and software tools for choosing organizational and technological solutions to maintain sewage collectors in an operable state to increase their service life. Such a tool must take into account a set of factors that affect the operation of sewer collectors and form a system, the implementation of which would improve the existing principles of monitoring the status of sewer collectors, identify effective organization and technological solutions of their renovation by taking into account factors that affect their safe operation, the facilities risk of accidents categories, conditions and parameters of works performance. For determining the optimal options for the renovation of the sewer collector using the developed mathematical and computer models, the results of problems solving were generalized: one-criterion optimization subject to the choice of one repair method; one-criterion optimization subject to the choice of different repair methods for the areas; multicriterion optimization.

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Ahyerre, M., G. Chebbo, B. Tassin, and E. Gaume. "Storm water quality modelling, an ambitious objective?" Water Science and Technology 37, no. 1 (January 1, 1998): 205–13. http://dx.doi.org/10.2166/wst.1998.0050.

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As a consequence of the awareness of the pollution impact of storm sewer overflows, managers need tools to evaluate and control stormwaters according to water quality criteria. After an experience of 25 years in storm water quality modelling, very few models are widely and regularly used. According to managers this is due to their cost and their low level of accuracy. The generation and the transport of the pollution in urban systems during a storm event are very complex because they concern many media and many space and time scales. Nevertheless, a typology of the existing models shows that this complexity has been inscribed into the models. This tendency towards complexity makes sewer quality models difficult to put into operation and three main difficulties can be underlined: doubtful mathematical formulation of processes, uncertainties on input and calibration data, difficulties and cost of calibration. Further research is needed to improve the modelling approach and basic knowledge, and we think that a clear distinction should be made between management tools and research models.

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Huang, Chung-Fu, Wei-Ting Chen, Chuan-Ksing Kao, Han-Jung Chang, Po-Min Kao, and Terng-Jou Wan. "Application of Fuzzy Multi-Objective Programming to Regional Sewer System Planning." Processes 11, no. 1 (January 6, 2023): 183. http://dx.doi.org/10.3390/pr11010183.

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Planning of sewer systems typically involves limitations and problems, regardless of whether traditional planning methods or optimization models are used. Such problems include non-quantifiability, fuzzy objectives, and uncertainties in decision-making variables which are commonly applied in the planning of any process. Particularly, uncertainties have prevented the inclusion of these variables in models. Consequently, the theoretical optional solution of the mathematical models is not the true optimum solution to practical problems. In this study, to solve the above problems for regional sewer system planning, multi-objective programming (MOP), nonlinear programming, mixed-integer programming, and compromise fuzzy programming were used. The objectives of this study were two-fold: (1) determination of the necessary decision-making variables or parameters, such as the optimum number of plants, piping layout, size of the plant, and extent of treatment; (2) establishment of a framework and methodology for optimal planning for designing a regional sewer system, matching demanded targets with the lowest cost, which would achieve the aim of lower space and energy requirements as well as consumption and high treatment efficiency for the purpose of meeting effluent standards. The findings of this study revealed that individual regional sewage treatment plants could be merged to form a centralized system. Land acquisition was difficult; thus, reducing the number of plants was required. Therefore, the compromise-fuzzy-based MOP method could effectively be used to build a regional sewer system plan, and the amount of in-plant establishment reached its maximized value with a minimized cost.

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Jung, Daniel, Laetitia Hatrait, Julien Gouello, Arnaud Ponthieux, Vincent Parez, and Christophe Renner. "Emission of hydrogen sulfide (H2S) at a waterfall in a sewer: study of main factors affecting H2S emission and modeling approaches." Water Science and Technology 76, no. 10 (August 4, 2017): 2753–63. http://dx.doi.org/10.2166/wst.2017.428.

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Abstract Hydrogen sulfide (H2S) represents one of the main odorant gases emitted from sewer networks. A mathematical model can be a fast and low-cost tool for estimating its emission. This study investigates two approaches to modeling H2S gas transfer at a waterfall in a discharge manhole. The first approach is based on an adaptation of oxygen models for H2S emission at a waterfall and the second consists of a new model. An experimental set-up and a statistical data analysis allowed the main factors affecting H2S emission to be studied. A new model of the emission kinetics was developed using linear regression and taking into account H2S liquid concentration, waterfall height and fluid velocity at the outlet pipe of a rising main. Its prediction interval was estimated by the residual standard deviation (15.6%) up to a rate of 2.3 g H2S·h−1. Finally, data coming from four sampling campaigns on sewer networks were used to perform simulations and compare predictions of all developed models.

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Safari, Mir Jafar Sadegh, Akbar Shirzad, and Mirali Mohammadi. "Sediment transport modeling in deposited bed sewers: unified form of May's equations using the particle swarm optimization algorithm." Water Science and Technology 76, no. 4 (May 18, 2017): 992–1000. http://dx.doi.org/10.2166/wst.2017.267.

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May proposed two dimensionless parameters of transport (η) and mobility (Fs) for self-cleansing design of sewers with deposited bed condition. The relationships between those two parameters were introduced in conditional form for specific ranges of Fs, which makes it difficult to use as a practical tool for sewer design. In this study, using the same experimental data used by May and employing the particle swarm optimization algorithm, a unified equation is recommended based on η and Fs. The developed model is compared with original May relationships as well as corresponding models available in the literature. A large amount of data taken from the literature is used for the models' evaluation. The results demonstrate that the developed model in this study is superior to May and other existing models in the literature. Due to the fact that in May's dimensionless parameters more effective variables in the sediment transport process in sewers with deposited bed condition are considered, it is concluded that the revised May equation proposed in this study is a reliable model for sewer design.

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Michelbach, S., G. Weiß, and H. Brombach. "CSO-MASTERPLAN FOR THE CITY OF WALDENBURG, GERMANY." Water Science and Technology 30, no. 1 (July 1, 1994): 43–52. http://dx.doi.org/10.2166/wst.1994.0005.

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The small town of Waldenburg in South Germany planned to continue the implementation of stormwater treatment. The CSO-Masterplan dated from the year 1976. Meanwhile, new guidelines were issued and new technologies became available, like mathematical sewer models. Since the ecological impact of stormwater treatment is today much more accounted for, it was decided to revise the CSO-Masterplan. The goal was to find a solution with minimized ecological impact at low costs. This urban hydrological study featured some unusual approaches. First, the present state of city, sewer system, treatment plant and receiving waters was analyzed in an interdisciplinary field study. Using the quantity-quality sewer model ASMI, the annual pollutant loads for various planning alternatives were calculated. This allowed statements about the environmental impact of each alternative, taking into account the sensitivity of the receiving waters known from the biological field study. The proposed final alternative saved nearly 1 million DM at a much lower impact on the environment compared with the original planning, showing that it is possible to cope equally with ecological and economical requirements.

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Huber, Franz, Georg Neugebauer, Thomas Ertl, and Florian Kretschmer. "Suitability Pre-Assessment of in-Sewer Heat Recovery Sites Combining Energy and Wastewater Perspectives." Energies 13, no. 24 (December 17, 2020): 6680. http://dx.doi.org/10.3390/en13246680.

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In many countries around the world heating (and cooling) has been and will remain the biggest energy sector, but it is still widely dominated by fossil energy sources today. Wastewater as a source of renewable energy contains large amounts of heat and due to its place-bound localization in urban sewer systems it is usually also situated in very close distance to potential heat consumers. However, one has to keep in mind that heat extraction from wastewater might have undesired impacts on temperature-sensitive treatment processes in the related wastewater treatment plant (WWTP). To assess the potential impact of in-sewer heat recovery on inflow temperature, two different approaches are available today: a simple (but less significant) alligation alternate, or very accurate (but less practical) mathematical models. To close the gap between practicability and significance this article introduces a novel approach to pre-assess the suitability of in-sewer heat recovery sites based on little and easily available data considering energy- and wastewater-related perspectives. A case study application demonstrates the informative value and general usability of the approach. Consequently, the proposed procedure can provide guidance and a template for related investigations at any place in a conventional (combined or separated) sewer system.

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Capodaglio, Andrea G. "INTEGRAL CONTROL REQUIREMENTS FOR SEWERAGE SYSTEMS." Water Science and Technology 30, no. 1 (July 1, 1994): 131–38. http://dx.doi.org/10.2166/wst.1994.0014.

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Sewerage systems and sewage treatment plants are often planned, designed and operated as totally separate entities. As a result, sewage treatment efficiency is subject to considerable variability, depending both on general hydrologic conditions in the urban watershed (wet versus dry periods), and on specific “instantaneous” operating conditions. It has been postulated that the integration of design and operation in urban drainage and wastewater treatment could allow minimization of the harmful effects of discharges from treatment plants, combined sewer overflows and surface runoff. This “ideal condition” can be achieved through the introduction of so-called “Real-Time Control” technology in sewerage collection and treatment operations. This paper examines the requirements of a hypothetical integrated sewer flow and sewage treatment model, the mathematical tools used to design and operate Real-Time Control systems, and the issues emerging from an integration of the conveyance and disposal aspects of the sewerage cycle.

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Lomeli, Luis Martinez, Abdon Iniguez, Prasanthi Tata, Nilamani Jena, Zhong-Ying Liu, Richard Van Etten, Arthur D. Lander, Babak Shahbaba, John S. Lowengrub, and Vladimir N. Minin. "Optimal experimental design for mathematical models of haematopoiesis." Journal of The Royal Society Interface 18, no. 174 (January 2021): 20200729. http://dx.doi.org/10.1098/rsif.2020.0729.

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The haematopoietic system has a highly regulated and complex structure in which cells are organized to successfully create and maintain new blood cells. It is known that feedback regulation is crucial to tightly control this system, but the specific mechanisms by which control is exerted are not completely understood. In this work, we aim to uncover the underlying mechanisms in haematopoiesis by conducting perturbation experiments, where animal subjects are exposed to an external agent in order to observe the system response and evolution. We have developed a novel Bayesian hierarchical framework for optimal design of perturbation experiments and proper analysis of the data collected. We use a deterministic model that accounts for feedback and feedforward regulation on cell division rates and self-renewal probabilities. A significant obstacle is that the experimental data are not longitudinal, rather each data point corresponds to a different animal. We overcome this difficulty by modelling the unobserved cellular levels as latent variables. We then use principles of Bayesian experimental design to optimally distribute time points at which the haematopoietic cells are quantified. We evaluate our approach using synthetic and real experimental data and show that an optimal design can lead to better estimates of model parameters.

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LaGrange, John D., and Michael L. Ratliff. "Curriculum spaces and mathematical models for curriculum design." Journal of Mathematical Psychology 102 (June 2021): 102523. http://dx.doi.org/10.1016/j.jmp.2021.102523.

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Dubas, Frédéric, and Kamel Boughrara. "Mathematical Models for the Design of Electrical Machines." Mathematical and Computational Applications 25, no. 4 (December 9, 2020): 77. http://dx.doi.org/10.3390/mca25040077.

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Williams, Justin C., Charles S. ReVelle, and Simon A. Levin. "Using mathematical optimization models to design nature reserves." Frontiers in Ecology and the Environment 2, no. 2 (March 2004): 98–105. http://dx.doi.org/10.1890/1540-9295(2004)002[0098:umomtd]2.0.co;2.

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YOO, D., BA OCNNOR, and DM MCDOWELL. "MATHEMATICAL MODELS OF WAVE CLIMATE FOR PORT DESIGN." Proceedings of the Institution of Civil Engineers 86, no. 3 (June 1989): 513–30. http://dx.doi.org/10.1680/iicep.1989.1973.

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Xu, Yiwen, Hritom Das, Yifu Gong, and Na Gong. "On Mathematical Models of Optimal Video Memory Design." IEEE Transactions on Circuits and Systems for Video Technology 30, no. 1 (January 2020): 256–66. http://dx.doi.org/10.1109/tcsvt.2018.2890383.

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Kawase, Y., and M. Moo-Young. "Mathematical models for design of bioreactors: Applications of." Chemical Engineering Journal 43, no. 1 (February 1990): B19—B41. http://dx.doi.org/10.1016/0300-9467(90)80048-h.

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Roels, Joop A. "Mathematical models and the design of biochemical reactors." Journal of Chemical Technology and Biotechnology 32, no. 1 (April 24, 2007): 59–72. http://dx.doi.org/10.1002/jctb.5030320110.

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Journal articles on the topic 'Sewer design Mathematical models'

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