scholarly journals Study of the effect of pipe materials and mixing phenomenon on trihalomethanes formation and diffusion in a laboratory-scale water distribution network

2017 ◽  
Vol 18 (1) ◽  
pp. 183-192 ◽  
Author(s):  
Rojacques Mompremier ◽  
Óscar Arturo Fuentes Mariles ◽  
Kebreab Ghebremichael ◽  
Ana Elisa Silva Martínez ◽  
José Elías Becerril Bravo
Keyword(s):  
Residence Time ◽  
Water Distribution ◽  
Distribution Network ◽  
Water Distribution Network ◽  
Laboratory Scale ◽  
Pipe Material ◽  
Sampling Locations ◽  
The Impact ◽  
And Diffusion ◽  
Pipe Materials

Abstract The objective of this study was to evaluate the factors that affect the formation and diffusion of disinfection by-products, especially trihalomethanes (THM), in a laboratory-scale water distribution network constructed with three different pipe materials. Sampling locations were chosen on the basis of residence time, pipe material and mixing zone. Water samples were collected and analyzed for temperature, pH, total organic carbon, turbidity, free chlorine and THM. Experiments were carried out where two different flow directions at cross junctions were studied. It was observed that for incoming flow at 90° with varying flow rate, mixing was shown to be incomplete where inflows tend to bifurcate rather than mix completely. For two incoming flows in opposing direction (180°), solute mixing has shown to be perfect due to the collision of the fluid streams. The results demonstrated how THM concentration can greatly vary in the same water distribution network due to the impact of pipe material, residence time and the outcome of mixing at cross junctions.

scholarly journals Assessing the Impact of DMAs and the Use of Boosters on Chlorination in a Water Distribution Network in Greece

Water ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2141
Author(s):  
Stavroula Tsitsifli ◽  
Vasilis Kanakoudis
Keyword(s):  
Water Distribution ◽  
Distribution Network ◽  
Water Distribution Network ◽  
Assessment Process ◽  
Water Volume ◽  
Pressure Management ◽  
Water Age ◽  
Chlorination Process ◽  
Management Measures ◽  
The Impact

Disinfection is one of the most important water treatment processes as it inactivates pathogens providing safe drinking water to the consumers. A fresh-water distribution network is a complex system where constant monitoring of several parameters and related managerial decisions take place in order for the network to operate in the most efficient way. However, there are cases where some of the decisions made to improve the network’s performance level, such as reduction of water losses, may have negative impacts on other significant operational processes such as the disinfection. In particular, the division of a water distribution network into district metered areas (DMAs) and the application of various pressure management measures may impact the effectiveness of the water chlorination process. Two operational measures are assessed in this paper: (a) the use of inline chlorination boosters to achieve more efficient chlorination; and (b) how the DMAs formation impacts the chlorination process. To achieve this, the water distribution network of a Greek town is chosen as a case study where several scenarios are being thoroughly analyzed. The assessment process utilizes the network’s hydraulic simulation model, which is set up in Watergems V8i software, forming the baseline to develop the network’s water quality model. The results proved that inline chlorination boosters ensure a more efficient disinfection, especially at the most remote parts/nodes of the network, compared to conventional chlorination processes (e.g., at the water tanks), achieving 100% safe water volume and consuming almost 50% less chlorine mass. DMAs’ formation results in increased water age values up to 8.27%, especially at the remote parts/nodes of the network and require more time to achieve the necessary minimum effective chlorine concentration of 0.2 mg/L. However, DMAs formation and pressure management measures do not threaten the chlorination’s efficiency. It is important to include water age and residual chlorine as criteria when optimizing water pressure and the division of DMAs.

scholarly journals Evolutionary multi-objective optimization of the design and operation of water distribution network: total cost vs. reliability vs. water quality

2006 ◽  
Vol 8 (3) ◽  
pp. 165-179 ◽  
Author(s):  
Raziyeh Farmani ◽  
Godfrey Walters ◽  
Dragan Savic
Keyword(s):  
Water Quality ◽  
Residence Time ◽  
Water Distribution ◽  
Distribution Network ◽  
Water Distribution Network ◽  
Loading Conditions ◽  
Pump Operation ◽  
Total Cost ◽  
Multi Objective ◽  
Storage Facilities

An expanded rehabilitation of the hypothetical water distribution network of Anytown, USA is considered. As well as pipe rehabilitation decisions, tank sizing, tank siting and pump operation schedules are considered as design variables. Inclusion of pump operation schedules requires consideration of water system operation over the demand pattern period. Design of distribution storage facilities involves solving numerous issues and trade-offs such as locations, levels and volume. This paper investigates the application of multi-objective evolutionary algorithms in the identification of the pay-off characteristic between total cost, reliability and water quality of Anytown's water distribution system. A new approach is presented for formulation of the model. To provide flexibility, the network must be designed and operated under multiple loading conditions. The cost of the solution includes the capital costs of pipes and tanks as well as the present value of the energy consumed during a specified period. Optimization tends to reduce costs by reducing the diameter of, or completely eliminating, pipes, thus leaving the system with insufficient capacity to respond to pipe breaks or demands that exceed design values without violating required performance levels. Here a resilience index is considered as a second objective to increase the hydraulic reliability and the availability of water during pipe failures. Considering reliability as one of the objectives in the optimization process will decrease the level of vulnerability for the solutions and therefore will result in robust networks. However, oversized distribution mains and storage tanks will have adverse effects on water age with negative effects on water quality due to low flow velocity and little turnover, respectively. Therefore, another objective in the design and operation of distribution systems with storage facilities is the minimization of residence time, thus minimizing deterioration in water quality, which is directly associated with the age of water. Residence time must include not only the time in tanks but also the travel time before and after the water's entry into the storage facilities. The residence time of the water in the network is considered as a surrogate measure of water quality. Results are presented for the pay-off characteristics between total cost, reliability and water quality, for 24 h design and five loading conditions.

scholarly journals Improved Hydraulic Simulation of Valve Layout Effects on Post-Earthquake Restoration of a Water Distribution Network

2020 ◽  
Vol 12 (8) ◽  
pp. 3492
Author(s):  
Jeongwook Choi ◽  
Doosun Kang
Keyword(s):  
Water Distribution ◽  
Distribution Network ◽  
Water Distribution Network ◽  
Seismic Damage ◽  
Hydraulic Analysis ◽  
Hydraulic Simulation ◽  
Restoration Process ◽  
Restoration Strategies ◽  
The Impact ◽  
Pressure Driven Analysis

To restore water pipes damaged by earthquakes, it is common to block the water flow by closing the associated shut-off valves. In this process, water supply suspension in the area connected to the isolated pipes is inevitable, which decreases the serviceability of the water distribution network (WDN). In this study, we identified the impact of valve layout (i.e., number and location) on system serviceability during a seismic damage restoration process. By conducting a pressure-driven-analysis (PDA) using EPANET 3.0, a more realistic hydraulic analysis could be carried out under the seismically damaged condition. Furthermore, by considering the valve-controlled segment in the hydraulic simulation, a more realistic water suspension area was determined, and efficient seismic damage restoration strategies were identified. The developed model was implemented on a WDN to demonstrate the effect of valve layout on the post-earthquake restoration process. Finally, effective restoration strategies were suggested for the application network.

Model of leak inspection and repair of water distribution network

2001 ◽  
Vol 1 (2) ◽  
pp. 225-230 ◽  
Author(s):  
Y. Hosoi
Keyword(s):  
Water Distribution ◽  
Distribution Network ◽  
Water Distribution Network ◽  
Distribution Area ◽  
Water Supply Systems ◽  
Pipe Material ◽  
Water Leakage ◽  
Inspection Interval ◽  
Pipe Breakage ◽  
Supply Systems

Theories and policies for the maintenance and renewal of water supply systems are required. The occurrence of water distribution pipe breakage and water leakage is influenced by pipe material, size and age as well as soil characteristics and transportation. The water leakage has to be discovered as soon as possible from the viewpoint of minimizing water loss. However, it costs more to increase inspections for water leakage. In this study, the model to determine the optimal inspection interval for water leakage of the water distribution network was examined. The optimal inspection interval was estimated to minimize the total cost of inspection, pipe repair and lost water. The developed model was applied to a water distribution area whose water main is 486 kilometres long. The area was divided into sub-area of 250 metres square. Those sub-areas were classified into 6 groups according to pipe break rate. The optimal inspection interval was obtained for each group and its validity examined by numerical simulation.

scholarly journals Study of the variation of haloacetic acids in a simulated water distribution network

2018 ◽  
Vol 19 (1) ◽  
pp. 88-96
Author(s):  
Rojacques Mompremier ◽  
Óscar Arturo Fuentes Mariles ◽  
José Elías Becerril Bravo ◽  
Kebreab Ghebremichael
Keyword(s):  
Distribution System ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution Network ◽  
Organic Content ◽  
Chlorine Concentration ◽  
Haloacetic Acids ◽  
Feed Water ◽  
Pipe Material ◽  
Pipe Materials

Abstract This paper presents the analysis of the variation of haloacetic acids (HAAs) for different pipe materials in a distribution system. The work involved an experimental study on a simulated distribution system assembled in the Hydraulic Laboratory of the Engineering Institute at the National Autonomous University of Mexico (Instituto de Ingeniería UNAM). Two different scenarios were investigated based on different pipe materials, variation of temperature and initial chlorine concentrations (4.0 and 4.5 mg/L). Feed water with varying amounts of organic content was dosed with varying amounts of chlorine concentration. Water samples were collected from different locations in the distribution system and analyzed for physicochemical properties and HAAs determination. The results of this research demonstrated that the concentration of HAAs in the different segments of the distribution systems varied depending on pipe material, initial chlorine concentration, pH, residence time and the presence of natural organic matter.

scholarly journals The Impact of Pressure Management Techniques on the Water Age in an Urban Pipe Network—The Case of Kos City Network

Proceedings ◽  
2018 ◽  
Vol 2 (11) ◽  
pp. 699 ◽  
Author(s):  
Anastasia Kravvari ◽  
Vasilis Kanakoudis ◽  
Menelaos Patelis
Keyword(s):  
Distribution Systems ◽  
Water Distribution ◽  
Distribution Network ◽  
Water Distribution Network ◽  
Optimization Criterion ◽  
Maximum Pressure ◽  
Pressure Management ◽  
Water Age ◽  
City Water ◽  
The Impact

The goal of this article is to study the impact that pressure management in distribution systems has, on the quality of the supplied water in terms of its water age, using the water distribution network of Kos city, capital of Kos Island in Greece was used as the case study network. This was achieved through network simulation using the Watercad V8i software, followed by the division of the network in district metered areas (DMA) and the placement of pressure reducing valves (PRV) in the entering nodes of each DMA. Research aimed also to optimize DMAs’ borders using the water age as the optimization criterion, instead of maximum pressure reduction. Different scenarios were tested on the calibrated and validated hydraulic model of Kos city water distribution network.

scholarly journals Research on Sensor Placement for Disaster Prevention in Water Distribution Networks for Important Users

2020 ◽  
Vol 12 (2) ◽  
pp. 723 ◽  
Author(s):  
Jiajia Wu ◽  
Donghui Ma ◽  
Wei Wang ◽  
Zhao Han
Keyword(s):  
Water Distribution ◽  
Distribution Network ◽  
Sensor Placement ◽  
Water Distribution Network ◽  
Distribution Networks ◽  
Water Distribution Networks ◽  
Impact Factors ◽  
Urban Water ◽  
Disaster Prevention ◽  
The Impact

Sensor placement for disaster prevention for important users in urban water distribution networks is essential for post-earthquake monitoring and repair. Herein, we proposed a sensor placement approach for disaster prevention monitoring for important users, to (a) improve the fault diagnosis ability of the water distribution network and to (b) guarantee the function of emergency services for key nodes after an earthquake. First, an evaluation system of node users’ disaster prevention impact factors was presented to evaluate the node influence degree from three aspects: post-earthquake leakage, emergency support and topology structure; and the weight values of node users’ disaster prevention impact factors were obtained. Second, a post-earthquake hydraulic analysis model based on the pressure-driven demand was used to calculate the water shortage ratio of nodes. Third, using the three-way clustering integration method, the results of four clustering techniques were integrated to divide the monitoring domain in the water distribution network based on sensitivity analysis. Finally, on basis of the sensitivity matrix, the division of the monitoring area and the impact factors of node users’ disaster prevention were combined to place sensors for post-earthquake disaster prevention in the water distribution network. Detailed computational experiments for a real urban water network in China were performed and compared with the results of other traditional techniques to evaluate the performance of the proposed approach. The results show that the approach is better than traditional methods. It not only considers the actual hydraulic information of the water distribution network, but also the important user nodes after an earthquake, and is of great significance for emergency command and rescue and disaster relief after an earthquake in the city.

Numerical Modelling of a Town Water Distribution Network Optimum location of quality sensors

2018 ◽  
Vol 69 (2) ◽  
pp. 358-364
Author(s):  
Gheorghe I. Lazar ◽  
Albert Titus Constantin ◽  
Marie Alice Ghitescu ◽  
Serban Vlad Nicoara
Keyword(s):  
Numerical Modelling ◽  
Distribution System ◽  
Water Distribution ◽  
Distribution Network ◽  
Water Distribution Network ◽  
Pollution Effects ◽  
Network Nodes ◽  
Study Case ◽  
The Impact ◽  
Contaminant Release

The analysis following a numerical simulation aims to establish the water distribution system vulnerability to a contaminant release and so to estimate the optimum locations of several quality sensors to warn against the pollution effects. The TEVA-SPOT software toolkit (as specific EPANET extension) was engaged upon a study case regarding the water distribution network of Ortisoara Town in Timi� County (4385 inhabitants). Five sets of sensors were consecutively considered for the numerical modelling, the engaged sensors being set for three values of the detection limit and of the response time. Assumed as a possible scenario, the designed sensors had to monitor the impact of injecting (at different given moments and network nodes) two types of contaminants (chemical and biological).

"Model and simulation of a real water distribution network to support emergency plans"

2018 ◽  
Author(s):  
Luisa Lavalle ◽  
Tatiana Patriarca ◽  
Bernard Daulne ◽  
Olivier Hautier ◽  
Ester Ciancamerla
Keyword(s):  
Distribution System ◽  
Water Distribution ◽  
Distribution Network ◽  
Water Distribution Network ◽  
Cyber Attacks ◽  
Emergency Plans ◽  
Electricity Grid ◽  
Horizon 2020 ◽  
Electrical Grid ◽  
The Impact

"This paper presents a water distribution network model to evaluate the impact of adverse events, such as faults and/or cyber-attacks, on a real water distribution system in a wider context which involves the interdependency with the electrical grid, in the frame of the Horizon 2020 project ATENA. The model has been developed by using a commercial simulator, which can address both the electrical and the water domain. Specific features and modules have been added to the simulator, in order to calculate the water level in tanks – an important and missing metric to support emergency plans. The interdependency among the electricity grid and the water network is considered throughout pumps, which are at the same time electrical loads and hydraulic devices. Two use cases, dealing with faults or cyber-attacks against the electrical grid affecting critical pumps or treatment stations, are investigated and the simulation results are reported."

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