Download or read book Network Water Quality Modeling with Stochastic Water Demands and Mass Dispersion written by and published by . This book was released on 2006 with total page 186 pages. Available in PDF, EPUB and Kindle. Book excerpt: A new computer model, ADRNET, is developed to predict the spatial and temporal distribution of disinfectant in a pipe network, considering stochastic water demands and unsteady mass dispersion. An Eulerian-Lagrangian scheme is combined with a numerical Green's Function technique to solve the advection-dispersion-reaction equation efficiently in network conditions. In a comparison with the industry standard advection-reaction water quality model (EPANET), ADRNET exhibits better agreement with field observations at locations where laminar flow is prevalent. Implementation of the ADRNET model is preceded by three ancillary studies. The first study investigates the effect of temporal averaging on stochastic pipe flows to identify the appropriate time scales for water quality modeling of distribution networks. For this purpose, a non-homogeneous Poison Rectangular Pulse (PRP) process is utilized to simulate high resolution residential water demands in a distribution network. Two water demand models are successfully established to demonstrate variability and frequency of regimes for PRP flows as function of time scale. The results show that the variance of time-averaged PRP random flows is inversely proportional to the time scale; the frequency of flow regimes depends on both the time scale and the mean of the random flows. The second study investigates the conditions under which mass dispersion is important in pipe networks through comparison of numerical simulations with and without dispersive transport. The results show that mass dispersion is always important in laminar flow zones, and the importance of dispersion increases with increasing pipe diameter but decreases with increasing of reaction rate coefficient. Finally, the effect of temporal scale on unsteady dispersion is studied through both theoretical analyses with periodic binary flow pulses and numerical simulation with PRP random laminar flows. For small diameter tubes, unsteady dispersion decreases with increasing time scale in unsteady laminar flows. For an actual network pipe, however, the time scale has little effect on unsteady dispersion in completely laminar flows.

Download or read book Stochastic Water Demand Modelling written by Mirjam Blokker and published by IWA Publishing. This book was released on 2011-09-19 with total page 181 pages. Available in PDF, EPUB and Kindle. Book excerpt: Water quality processes in the drinking water distribution network are strongly influenced by the flow velocity and residence time of the water in the network. In order to understand how the water quality changes in the drinking water distribution network, a good understanding of hydraulics is required. Specifically in the periphery of the network, where customers are connected, the hydraulics can change rapidly. During the night time the water is almost stagnant and the residence time increases. In the morning, when everybody gets up and flushes the toilet and takes a shower, high flow velocities can occur. During the remainder of the day flow velocities are low. The stochastic endues model SIMDEUM was developed to simulate water use on a small time scale (1 s) and small spatial scale (per fixture). SIMDEUM enables a good model of flow velocities, residence times and the connected water quality processes in the water distribution network. Stochastic Water Demand Modelling: Hydraulics in Water Distribution Networks describes the requirements of hydraulics in water quality modelling and provides insight into the development of detailed residential and non-residential water demand models. The book illustrates the use of detailed demand models in water quality models with respect to the variation in residence times and the relation with particle accumulation and resuspension. The models are compared to measurements in several real drinking water distribution networks.

Download or read book A Full scale Simulation Study of Stochastic Water Demands on Distribution System Transport written by Xueyao Yang and published by . This book was released on 2010 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt: Typical network modeling in distribution system analysis assumes the water demands are known and constant over 1 hour. However, as utilities move towards "all-pipe" network models, continuing to ignore the stochastic water demands may not adequately account for the impacts of demand variability on the underlying transport and water quality characteristics. The objective of this research is to evaluate the potential impacts of different levels of temporal aggregation of water demands on the underlying hydraulic, transport, and water quality simulations for both a small network and a large "all-pipe" network system. A non-homogeneous Poisson Rectangular Pulse model was used to generate stochastic water demands aggregated at 1-min, 10-min, and 1-hr time steps, and linked with EPANET to perform hydraulic and water quality simulations. The impacts of the three temporal aggregations of water demands were evaluated with respect to: 1) hydraulics by evaluating pressure and flow rate variability; 2) transport and water quality characteristics using "conservative chemical intrusion" events and evaluating transport times and cumulative mass. Additional studies were performed to interpret the chemical analysis within a risk analysis framework, and investigated the impact of temporal aggregation with different injection durations. For a small skeletonized network, results showed for main trunk lines, the demand variability had little influence on the flow rate, chemical concentration, and risk assessment. However, as dead end nodes or pipes were analyzed, there was an increase in the flow rate variability with decreasing temporal aggregation that impacted the chemical concentration time series and risk assessment by altering the travel paths and times. For the large "all-pipe" network model, the results illustrated a greater frequency in flow reversals as well as meaningful differences in the initial arrival time and half-mass arrival time of chemical with decreasing temporal aggregation scales. Upon analyzing the Monte Carlo ensemble of results, the majority of nodes that resulted in meaningful initial chemical arrival time differences tended to be located at the edges of the network. With respect to the half-mass arrival time, a spatial analysis indicated there were a number of nodes within a blending region that had meaningful differences within a majority of the Monte Carlo realizations. Finally, a comparison of the stochastic water demand simulations to the original deterministic simulation indicated that the intra-hour variability resulting from the stochastic demands was more important than the variability resulting from the temporal aggregation scale. The results associated with a risk assessment also showed meaningful differences in the time until 1% and 50% of the population at a node infected by a toxic chemical between the shorter temporal aggregation scales and the 1-hr case. The impacts of injection duration illustrated the injection duration had little impact on the initial chemical arrival time. However, decreasing the injection duration had greater impacts on the differences of half-mass chemical arrival time and cumulative mass between the 10-min and 1-hr aggregation cases. These results indicate that there are portions of a distribution system where the typical network modeling assumptions may not be appropriate to adequately represent localized transport.

Download or read book Integrating Water Systems written by Joby Boxall and published by CRC Press. This book was released on 2009-07-24 with total page 834 pages. Available in PDF, EPUB and Kindle. Book excerpt: A collection of articles by leading international experts on modeling and control of potable water distribution and sewerage collection systems, focusing on advances in sensors, instrumentation and communications technologies; assessment of sensor reliability, accuracy and fitness; data management including SCADA and GIS; system

Download or read book Sustainable Water Technologies written by Daniel H. Chen and published by CRC Press. This book was released on 2016-10-14 with total page 333 pages. Available in PDF, EPUB and Kindle. Book excerpt: Development of advanced technologies is a critical component in overcoming the looming water crisis. Stressing emerging technologies and strategies that facilitate water sustainability for future generations, the second volume in the two-volume set Sustainable Water Management and Technologies provides current and forthcoming technologies research, development, and applications to help ensure availability of water for all. The book emphasizes emerging nanotechnology, biotechnology, and information technology?applications as well as sustainable processes and products to protect the environment and human health, save water and energy, and minimize material use. It also discusses such topics as groundwater transport, protection, and remediation, industrial and wastewater treatment, reuse, and disposal, membrane technology for water purification and desalination, treatment and disposal in unconventional oil and gas development, biodegradation, and bioremediation for soil and water. ? Stresses emerging technologies and strategies that facilitate water sustainability. Covers a wide array of topics including drinking water, wastewater, and groundwater treatment, protection, and remediation. Discusses oil and gas drilling impacts and pollution prevention, membrane technology for water desalination and purification, biodegradation, and bioremediation for soil and water. Details emerging nanotechnology, biotechnology, and information technology applications, as well as sustainable processes and products.

Download or read book Water Management Challenges in Global Change written by B. Ulanicki and published by CRC Press. This book was released on 2020-11-25 with total page 705 pages. Available in PDF, EPUB and Kindle. Book excerpt: Water Management Challenges in Global Change contains the proceedings of the 9th Computing and Control for the Water Industry (CCWI2007) and the Sustainable Urban Water Management (SUWM2007) conferences. The rationale behind these conferences is to improve the management of urban water systems through the development of computerbased methods. Issues such as economic globalisation, climate changes and water shortages call for a new approach to water systems management, which addresses the relevant technical, social and economic aspects. This collection represents the views of academic and industrial experts from a number of countries, who provide technical solutions to current water management problems and present a vision for addressing the global questions. The themes underlying many of the contributions include energy and material savings, water savings and the integration of different aspects of water management. The papers are grouped into three themes covering water distribution systems, sustainable urban water management and modelling of wastewater treatment plants. The water distribution topics cover asset and information management, planning, monitoring and control, hydraulic modelling of steady state and transients, water quality and treatment, demand and leakage management, optimisation, design and decision support systems, as well as reliability and security of water distribution systems. The sustainable urban water management topics include urban drainage systems, water reuse, social aspects of water management and also selected facets of water resources and irrigation. Computer control of wastewater treatment plants has been seen as less advanced than that of clean water systems. To address this imbalance, this book presents a number of modelling techniques developed specifically for these plants. Water Management Challenges in Global Change will prove to be invaluable to water and environmental engineering researchers and academics; managers, engineers and planners; and postgraduate students.

Download or read book Numerical Modelling of Hydrodynamics for Water Resources written by Pilar Garcia Navarro and published by CRC Press. This book was released on 2007-09-17 with total page 402 pages. Available in PDF, EPUB and Kindle. Book excerpt: Overland flow modelling has been an active field of research for some years, but developments in numerical methods and computational resources have recently accelerated progress, producing models for different geometries and types of flows, such as simulations of canal and river networks. Flow in canals has traditionally been described using

Download or read book Stochastic Modeling for Water Quality Management written by Richard G. Krutchkoff and published by . This book was released on 1971 with total page 416 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Water Quality Modeling written by Mervin D. Palmer and published by World Bank Publications. This book was released on 2001-01-01 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt: Annotation This book provides a broad based understanding of the water quality prediction process and evaluates the merits and cost effectiveness in using water quality models under field conditions.

Download or read book Surface Water Quality Modeling written by Steven C. Chapra and published by Waveland Press. This book was released on 2008-12-17 with total page 865 pages. Available in PDF, EPUB and Kindle. Book excerpt: National and international interest in finding rational and economical approaches to water-quality management is at an all-time high. Insightful application of mathematical models, attention to their underlying assumptions, and practical sampling and statistical tools are essential to maximize a successful approach to water-quality modeling. Chapra has organized this user-friendly text in a lecture format to engage students who want to assimilate information in manageable units. Comical examples and literary quotes interspersed throughout the text motivate readers to view the material in the proper context. Coverage includes the necessary issues of surface water modeling, such as reaction kinetics, mixed versus nonmixed systems, and a variety of possible contaminants and indicators; environments commonly encountered in water-quality modeling; model calibration, verification, and sensitivity analysis; and major water-quality-modeling problems. Most formulations and techniques are accompanied by an explanation of their origin and/or theoretical basis. Although the book points toward numerical, computer-oriented applications, strong use is made of analytical solutions. In addition, the text includes extensive worked examples that relate theory to applications and illustrate the mechanics and subtleties of the computations.

Download or read book Water Quality Modelling for Rivers and Streams written by Marcello Benedini and published by Springer Science & Business Media. This book was released on 2013-02-11 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt: The main objective of the Water Framework Directive in the European countries is to achieve a “good status” of all the water bodies, in the integrated management of river basins. In order to assess the impact of improvement measures, water quality models are necessary. During the previous decades the progress in computer technology and computational methods has supported the development of advanced mathematical models for pollutant transport in rivers and streams. This book is intended to provide the fundamental knowledge needed for a deeper understanding of these models and the development of new ones, which will fulfil future quality requirements in water resources management. This book focuses on the fundamentals of computational techniques required in water quality modelling. Advection, dispersion and concentrated sources or sinks of contaminants lead to the formulation of the fundamental differential equation of pollutant transport. Its integration, according to appropriate initial and boundary conditions and with the knowledge of the velocity field, allows for pollutant behaviour to be assessed in the entire water body. An analytical integration is convenient only in one-dimensional approach with considerable simplification. Integration in the numerical field is useful for taking into account particular aspects of water body and pollutants. To ensure their reliability, the models require accurate calibration and validation, based on proper data, taken from direct measurements. In addition, sensitivity and uncertainty analysis are also of utmost importance. All the above items are discussed in detail in the 21 chapters of the book, which is written in a didactic form for professionals and students.

Download or read book Stochastic Modeling for Water Quality Management written by Stochastics Incorporated (Blacksburg, Va.) and published by . This book was released on 1971 with total page 395 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Design of Networks for Monitoring Water Quality written by Thomas Gayler Sanders and published by Water Resources Publication. This book was released on 1983 with total page 350 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Water Quality Modeling for Wasteload Allocations and TMDLs written by Wu-Seng Lung and published by John Wiley & Sons. This book was released on 2001-04-30 with total page 354 pages. Available in PDF, EPUB and Kindle. Book excerpt: Complete, practical coverage of pollution control regulations and water quality modeling Water Quality Modeling for Wasteload Allocations and TMDLs provides practical guidance for engineers charged with determining the volume and character of wastewater that a body of water can receive without suffering environmental damage. Following the discussion on water pollution control regulations and their relationships to water quality modeling and wasteload allocation for determining the total maximum daily load (TMDL), the first half of the book focuses on quantifying the model coefficients to characterize physical, chemical, and biological processes of a variety of water quality problems. The remainder of the book guides engineers in the application of EPA-developed models for regulatory use. Presenting numerous case studies and a substantial amount of data, this comprehensive guide: * Covers practical applications of wasteload allocation * Provides guidance to develop technical information for obtaining National Pollution Discharge Elimination System (NPDES) permits * Demonstrates the application of STREAM, QUAL2E, WASP, and HAR03 Water Quality Modeling for Wasteload Allocations and TMDLs is an essential resource for state and federal water quality agencies, consulting engineering firms, publicly owned treatment works, environmental biologists and chemists, and public health officials involved with pollution control.

Download or read book Dissertation Abstracts International written by and published by . This book was released on 2006 with total page 774 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Predictive Models for Water Quality in Distribution Systems written by J. Clement and published by American Water Works Association. This book was released on 2005-04-30 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt: There are two groups of specialists involved in the development and application of water quality models, each of which have a different perspective on the use of models: Academics and scientists - chemistry specialists and microbiologists who develop the models. Practitioners - modelers and distribution engineers who use them to solve problems. There are limitations and constraints in the characterization of the underlying processes and the practical application of models to distribution networks, which require further research. The objectives of the research were to characterize the current state of predictive distribution system water quality models and to identify critical research needs for their improvement. The project reviewed both the development and application of models. The report is intended to both steer future research and to act as a general reference on water quality modeling. The report combines a literature review with the practical experience of the project team. The content of a draft report was discussed at an international workshop attended by academics, engineers, scientists, and hydraulic modelers with the objective of agreeing on specific research needs necessary to improve predictive modeling for water quality in distribution systems. The conclusions of the report are derived from the workshop and form the basis of 11 specific research briefs that have been submitted to AwwaRF for consideration of funding. Researchers often focus on modeling the individual processes that control water quality rather than fully modeling water quality throughout distribution systems. For these "process models" to be applied to real distribution networks, they need to be extended to take in account the physical characteristics of the system?the special and temporal variations in flow, velocity and water age, and the effects of mixing water that has traveled along different flow paths.

Download or read book Water Resource Systems Planning and Management written by Daniel P. Loucks and published by Springer. This book was released on 2017-03-02 with total page 635 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is open access under a CC BY-NC 4.0 license. This revised, updated textbook presents a systems approach to the planning, management, and operation of water resources infrastructure in the environment. Previously published in 2005 by UNESCO and Deltares (Delft Hydraulics at the time), this new edition, written again with contributions from Jery R. Stedinger, Jozef P. M. Dijkman, and Monique T. Villars, is aimed equally at students and professionals. It introduces readers to the concept of viewing issues involving water resources as a system of multiple interacting components and scales. It offers guidelines for initiating and carrying out water resource system planning and management projects. It introduces alternative optimization, simulation, and statistical methods useful for project identification, design, siting, operation and evaluation and for studying post-planning issues. The authors cover both basin-wide and urban water issues and present ways of identifying and evaluating alternatives for addressing multiple-purpose and multi-objective water quantity and quality management challenges. Reinforced with cases studies, exercises, and media supplements throughout, the text is ideal for upper-level undergraduate and graduate courses in water resource planning and management as well as for practicing planners and engineers in the field.