scholarly journals Assessment of water quality modelling capabilities of EPANET multiple species and pressure-dependent extension models

2013 ◽  
Vol 13 (4) ◽  
pp. 1161-1166 ◽  
Author(s):  
Alemtsehay G. Seyoum ◽  
Tiku T. Tanyimboh ◽  
Calvin Siew
Keyword(s):  
Water Quality ◽  
Distribution Systems ◽  
Operating Conditions ◽  
Quality Analysis ◽  
Future Research ◽  
Operating Pressure ◽  
Quality Model ◽  
Water Age ◽  
First Order ◽  
Multiple Species

The need for accurately predicting water quality through models has increasingly been crucial in meeting rigorous standards and customer expectations. There are several endeavours on developing robust water quality models for water distribution systems. In this paper, two variants of the EPANET 2 water quality model have been assessed to inform future research. The models are the multiple species extension EPANET-MSX and the pressure-dependent extension EPANET-PDX. Water quality analysis was conducted on a hypothetical network considering various operating pressure conditions. Different kinetic models were employed to simulate water quality. First order, limited first order and zero order models were used for predicting chlorine residual, disinfection by-products (DBPs) and water age respectively. Generally, EPANET-MSX and EPANET-PDX provided identical water quality results for normal operating conditions with adequate pressure but different results for pressure-deficient networks. Also, a parallel first order model with fast and slow reacting components was used for chlorine decay and DBPs using the EPANET-MSX model for a network operating under normal pressure conditions.

scholarly journals Enhanced Water Age Performance Assessment in Distribution Networks

Water ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 2574
Author(s):  
Laura Monteiro ◽  
Ricardo Algarvio ◽  
Dídia Covas
Keyword(s):  
Water Quality ◽  
Performance Assessment ◽  
Reference Values ◽  
Distribution Systems ◽  
Water Distribution ◽  
Distribution Networks ◽  
Operating Conditions ◽  
Water Age ◽  
Major Improvement ◽  
Age Limits

Water age is frequently used as a surrogate for water quality in distribution networks and is often included in modelling and optimisation studies, though there are no reference values or standard performance functions for assessing the network behaviour regarding water age. This paper presents a novel methodology for obtaining enhanced system-specific water age performance assessment functions, tailored for each distribution network. The methodology is based on the establishment of relationships between the chlorine concentration at the sampling nodes and simulated water age. The proposed methodology is demonstrated through application to two water distribution systems in winter and summer seasons. Obtained results show a major improvement in comparison with those obtained by published performance functions, since the water age limits of the performance functions used herein are tailored to the analysed networks. This demonstrates that the development of network-specific water age performance functions is a powerful tool for more robustly and reliably defining water age goals and evaluating the system behaviour under different operating conditions.

scholarly journals A GPU-based 2D shallow water quality model

2020 ◽  
Vol 22 (5) ◽  
pp. 1182-1197
Author(s):  
Geovanny Gordillo ◽  
Mario Morales-Hernández ◽  
I. Echeverribar ◽  
Javier Fernández-Pato ◽  
Pilar García-Navarro
Keyword(s):  
Water Quality ◽  
Shallow Water ◽  
Graphics Processing Unit ◽  
Temporal Distribution ◽  
Water Quality Model ◽  
Quality Analysis ◽  
Test Case ◽  
Processing Unit ◽  
Quality Model ◽  
Central Processing

Abstract In this study, a 2D shallow water flow solver integrated with a water quality model is presented. The interaction between the main water quality constituents included is based on the Water Quality Analysis Simulation Program. Efficiency is achieved by computing with a combination of a Central Processing Unit (CPU) and a Graphics Processing Unit (GPU) device. This technique is intended to provide robust and accurate simulations with high computation speedups with respect to a single-core CPU in real events. The proposed numerical model is evaluated in cases that include the transport and reaction of water quality components over irregular bed topography and dry–wet fronts, verifying that the numerical solution in these situations conserves the required properties (C-property and positivity). The model can operate in any steady or unsteady form allowing an efficient assessment of the environmental impact of water flows. The field data from an unsteady river reach test case are used to show that the model is capable of predicting the measured temporal distribution of dissolved oxygen and water temperature, proving the robustness and computational efficiency of the model, even in the presence of noisy signals such as wind speed.

scholarly journals Water Quality Model for Distribution Systems by Neural Networks.

1999 ◽  
Vol 27 ◽  
pp. 593-600
Author(s):  
Toyono INAKAZU ◽  
Shin OBATA ◽  
Akira KOIZUMI ◽  
Yasuyuki SAKAKIBARA
Keyword(s):  
Neural Networks ◽  
Water Quality ◽  
Distribution Systems ◽  
Water Quality Model ◽  
Quality Model

Condensation Induced Waterhammer in District Steam Distribution Systems

2013 ◽  
Author(s):  
Sri K. Sinha ◽  
Robert S. Vecchio ◽  
Paul M. Bruck ◽  
Thomas C. Esselman ◽  
Gregory Zysk ◽  
...  
Keyword(s):  
New York ◽  
Distribution Systems ◽  
Construction Materials ◽  
Operating Conditions ◽  
Operating Pressure ◽  
Excessive Pressure ◽  
Root Cause ◽  
Steam Pipe ◽  
Event Based ◽  
Steam System

Condensation induced waterhammer in district steam distribution systems can cause catastrophic rupture of piping and inflict severe damage to personnel, property, and environment. On July 18, 2007, a 20-in. diameter underground steam pipe in New York City ruptured at 5:56 p.m. at the intersection of 41st Street and Lexington Avenue in midtown Manhattan. At the time of rupture, the steam system was in service delivering steam to the customers at an operating pressure of approximately 160 psig and a steam temperature of approximately 370°F. The incident opened a large cavity measuring approximately 32 ft × 32 ft × 18 ft deep at the intersection of 41st Street and Lexington Avenue. The pipe rupture released steam, condensate, water, pipe insulation and various construction materials to the environment. Consolidated Edison Co. of New York, Inc. (Con Edison) and LPI (Lucius Pitkin, Inc.) investigated the event. Based on detailed metallurgical and engineering evaluations of the steam system configuration and operating conditions, it was concluded that the steam pipe ruptured as a result of excessive pressure caused by condensation-induced waterhammer. This paper presents a summary of the engineering evaluation, root cause, and conditions leading to the pipe rupture and provides measures which can be taken to reduce the likelihood of such a failure and enhance public safety.

Determination of cast iron pipe wall decay coefficient for combined chlorine in a municipal water distribution system

2015 ◽  
Vol 42 (4) ◽  
pp. 250-258 ◽  
Author(s):  
Megan J. Liu ◽  
Stephen Craik ◽  
David Z. Zhu
Keyword(s):  
Water Quality ◽  
Cast Iron ◽  
Distribution System ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution System ◽  
Water Quality Model ◽  
Quality Model ◽  
Decay Coefficient ◽  
Municipal Water

Predicting disinfectant concentrations in water distribution systems using water quality models requires the input of the wall decay coefficient of the disinfectant. In this study, field water sampling data was integrated with network hydraulic and water quality model simulations of a section of the municipal water distribution system in the City of Edmonton, composed of predominantly cast iron piping, to determine a wall decay coefficient for combined chlorine (chloramine). Unique combined chlorine wall decay coefficients that provided the best fit of model-predicted chlorine concentrations to the field data were determined at two temperatures. Using the determined wall decay coefficients, the water quality model can be used to predict combined chlorine concentrations.

Extending Uncertainty Analysis of a Hydrodynamic-Water Quality Modelling System using High Level Architecture (HLA)

2005 ◽  
Vol 40 (1) ◽  
pp. 59-70 ◽  
Author(s):  
Karl-Erich Lindenschmidt ◽  
Jan Rauberg ◽  
Fred B. Hesser
Keyword(s):  
Water Quality ◽  
Uncertainty Analysis ◽  
Computer Architecture ◽  
Nutrient Dynamics ◽  
Simulation Software ◽  
Quality Analysis ◽  
High Level Architecture ◽  
Quality Model ◽  
High Level ◽  
The Impact

Abstract This paper illustrates the coupling of water quality model components in High Level Architecture (HLA), a computer architecture for constructing distributed simulations. HLA facilitates interoperability among different simulations and simulation types and promotes reuse of simulation software modules. It was originally developed for military applications but the platform is finding increasing applicability for civilian purposes. The models from the Water Quality Analysis Simulation Program (WASP5) were implemented in HLA to extend its Monte Carlo uncertainty analysis capabilities. The models include DYNHYD (hydrodynamics), EUTRO (phytoplankton and nutrient dynamics) and TOXI (sediment and micropollutant transport). The uncertainty analysis investigated the impact of errors in the hydrodynamic parameters (weir discharge and roughness coefficients) and boundary conditions (upstream and tributary discharge) on the uncertainty in the water quality output variables. It was found that the contribution of the hydrodynamic parameter error to the water quality output uncertainty is comparable to that obtained from the error in the water quality parameters. The error in the boundary condition input data is also an important contributor to model uncertainty.

scholarly journals Development and identification of a multi-species water quality model for reclaimed water distribution systems

2015 ◽  
Vol 5 (3) ◽  
pp. 360-371
Author(s):  
Shun Li ◽  
Fu Sun ◽  
Siyu Zeng ◽  
Xin Dong ◽  
Pengfei Du
Keyword(s):  
Water Quality ◽  
Distribution Systems ◽  
Water Distribution ◽  
Reclaimed Water ◽  
Water Distribution Systems ◽  
Water Quality Model ◽  
Bulk Liquid ◽  
Model Parameters ◽  
Quality Model ◽  
Long Distance

With the rapid development of a centralized wastewater reuse scheme in China, water quality concerns arise considering the long-distance transport of reclaimed water in distribution systems from wastewater treatment plants to points of use. To this end, a multi-species water quality model for reclaimed water distribution systems (RWDSs) was developed and validated against the data from part of a full-scale RWDS in Beijing. The model could simulate organics, ammonia nitrogen, residual chlorine, inert particles, and six microbial species, i.e. fecal coliforms, Enterococcus spp., Salmonella spp., Mycobacterium spp., and other heterotrophic and autotrophic bacteria, in both the bulk liquid and the biofilm. Altogether, 56 reaction processes were involved, and 37 model parameters and seven initial values were identified. Despite the limited monitoring data and the associated gross uncertainty, the model could simulate the reclaimed water quality in the RWDS with acceptable accuracy. Regional sensitivity analysis suggested that the model had a balanced structure with a large proportion of sensitive parameters, and the sensitivity of model parameters could be reasonably interpreted by current knowledge or observation. Furthermore, the most sensitive model parameters could generally be well identified with uncertainties significantly reduced, which also favored the trustworthiness of the model. Finally, future plans to improve and apply the model were also discussed.

Estimation of the fate of microbial water quality contaminants in a South African river

1995 ◽  
Vol 31 (5-6) ◽  
pp. 271-274
Author(s):  
D. Hohls ◽  
G. du Plessis ◽  
S. N. Venter ◽  
M. C. Steynberg ◽  
C. M. E. De Wet ◽  
...  
Keyword(s):  
Water Quality ◽  
South African ◽  
Stream Water ◽  
Water Quality Management ◽  
Cost Effective ◽  
Stream Water Quality ◽  
Quality Model ◽  
Microbial Water Quality ◽  
First Order ◽  
Effective Manner

The aim of this study was to evaluate the validity of assumptions, regarding assimilative capacity for microbial contaminants, implicit in microbial water quality management in South Africa. A one dimensional steady state stream water quality model, assuming first order decay of microbial water quality variables, was employed in an attempt to describe and predict microbial water quality in the chosen catchment. Based on the faecal coliform counts the results indicated that the processes of decay and dilution were inadequate to yield water quality which complied with South African and international guidelines for the domestic and recreational use of water. It was also found that a first order decay model can, with fairly limited data, allow a manager to investigate different microbial water quality scenarios in a cost-effective manner.

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