Simulated Water Distribution System Research Articles

Hydraulic Analysis study and redesign of the water distribution system simulation using GIS- EPANET, case study: Laylan sub-district, Kirkuk city, Iraq

Hydraulic Analysis study and redesign of the water distribution system simulation using GIS- EPANET, case study: Laylan sub-district, Kirkuk city, Iraq

Effect of booster disinfection on the prevalence of microbial antibiotic resistance and bacterial community in a simulated drinking water distribution system

Booster disinfection was often applied to control the microorganism's growth in long-distance water supply systems. The effect of booster disinfection on the changing patterns of antibiotic resistance and bacterial community was investigated by a simulated water distribution system (SWDS). The results showed that the antibiotic resistance bacteria (ARB) and antibiotic resistance genes (ARGs) were initially removed after dosing disinfectants (chlorine and chloramine), but then increased with the increasing water age. However, the relative abundance of ARGs significantly increased after booster disinfection both in buck water and biofilm, then decreased along the pipeline. The pipe materials and disinfectant type also affected the antibiotic resistance. Chlorine was more efficient in controlling microbes and ARGs than chloramine. Compared with UPVC and PE pipes, SS pipes had the lowest total bacteria, ARB concentration, and ARB percentage, mainly due to higher disinfectant residuals and a smoother surface. The significant correlation (rs = 0.77, p < 0.001) of the 16S rRNA genes was observed between buck water and biofilm, while the correlations of targeted ARGs were found to be weak. Bray-Curtis similarity index indicated that booster disinfection significantly changed the biofilm bacterial community and the disinfectant type also had a marked impact on the bacterial community. At the genus level, the relative abundance of Pseudomonas, Sphingomonas, and Methylobacterium significantly increased after booster disinfection. Mycobacterium increased after chloramination while decreased after chlorination, indicating Mycobacterium might resist chloramine. Pseudomonas, Methylobacterium, and Phreatobacter were found to correlate well with the relative abundance of ARGs. These results highlighted antibiotic resistance shift and bacterial community alteration after booster disinfection, which may be helpful in controlling potential microbial risk in drinking water.

Design of water distribution pipes alongside modeling and simulation of water distribution system for efficient management

Design of water distribution pipes alongside modeling and simulation of water distribution system for efficient management

High-Fidelity Cyber and Physical Simulation of Water Distribution Systems. I: Models and Data

High-Fidelity Cyber and Physical Simulation of Water Distribution Systems. I: Models and Data

High-Fidelity Cyber and Physical Simulation of Water Distribution Systems. II: Enabling Cyber-Physical Attack Localization

High-Fidelity Cyber and Physical Simulation of Water Distribution Systems. II: Enabling Cyber-Physical Attack Localization

Biofilm Control in Flow-Through Systems Using Polyvalent Phages Delivered by Peptide-Modified M13 Coliphages with Enhanced Polysaccharide Affinity.

Eradication of biofilms that may harbor pathogens in water distribution systems is an elusive goal due to limited penetration of residual disinfectants. Here, we explore the use of engineered filamentous coliphage M13 for enhanced biofilm affinity and precise delivery of lytic polyvalent phages (i.e., broad-host-range phages lysing multiple host strains after infection). To promote biofilm attachment, we modified the M13 major coat protein (pVIII) by inserting a peptide sequence with high affinity for Pseudomonas aeruginosa (P. aeruginosa) extracellular polysaccharides (commonly present on the surface of biofilms in natural and engineered systems). Additionally, we engineered the M13 tail fiber protein (pIII) to contain a peptide sequence capable of binding a specific polyvalent lytic phage. The modified M13 had 102- and 5-fold higher affinity for P. aeruginosa-dominated mixed-species biofilms than wildtype M13 and unconjugated polyvalent phage, respectively. When applied to a simulated water distribution system, the resulting phage conjugates achieved targeted phage delivery to the biofilm and were more effective than polyvalent phages alone in reducing live bacterial biomass (84 vs 34%) and biofilm surface coverage (81 vs 22%). Biofilm regrowth was also mitigated as high phage concentrations induced residual bacteria to downregulate genes associated with quorum sensing and extracellular polymeric substance secretion. Overall, we demonstrate that engineered M13 can enable more accurate delivery of polyvalent phages to biofilms in flow-through systems for enhanced biofilm control.

Analysis of Water Distribution System under Uncertainty Based on Genetic Algorithm and Trapezoid Fuzzy Membership

AbstractIn most studies of hydraulic simulation of water distribution systems (WDS), the uncertain input parameters such as nodal demands, pipe roughness coefficients, pipe diameters, water levels ...

Chlorination contributes to multi-antibiotic resistance in a pilot-scale water distribution system

Abstract The generation and dissemination of antibiotic resistance bacteria (ARB) and antibiotic resistance genes (ARGs) in the environment has become a critical risk to human health. This study is based on a pilot-scale simulated water distribution system to understand the effects of chlorine disinfection treatment (without free chlorine) on ARB and ARGs in biofilms. The hydraulic parameters and pipe materials of the system were simulated based on a drinking water system. The results of the colony counts showed that bacterial multi-antibiotic resistance could be enhanced 13-fold in the biofilms of the pipeline. The use of high-throughput qPCR (HT-qPCR) indicated that the total relative abundance of ARGs in biofilm samples increased significantly (p &amp;lt; 0.05), while the diversity of bacteria was shown to be reduced via taxonomic analysis of the V3–V4 region of 16S rRNA. The prominent types of ARGs were conferred resistance by aminoglycoside and β-lactam after the chlorine disinfection treatment, and antibiotic deactivation was the main mechanism. Phyla Proteobacteria had the highest abundance in both treatment and control groups but decreased from 70.81% (initial biofilm sample) to 26.09% (the sixth-month biofilm sample) in the treatment groups. The results show that the chlorine disinfection plays a role in the risk of development of bacterial antibiotic resistance in pipe networks owing to bacteria in biofilms. This study was the first to investigate the contribution of chlorination without free chlorine to the bacterial community shift and resistome alteration in biofilms at a pilot-test level.

Evaluating the Performance of Agricultural Water Distribution Systems Using FIS, ANN and ANFIS Intelligent Models

Increasing water use efficiency in the agricultural sector requires the use of appropriate methods for intelligent performance evaluation of surface water distribution systems in agriculture. Therefore, in this study a systematic approach was developed for operational performance appraisal of the agricultural water distribution systems. For this purpose, Fuzzy Inference System (FIS), Artificial Neural Network (ANN), and Adaptive Neuro-Fuzzy Inference System (ANFIS) were used to evaluate the technical performance of irrigation network, considering the uncertainties in the water exploitation process. The performance of the developed models was studied on the Roodasht irrigation canal, located in central Iran, which suffers from severe fluctuations in the inflow, by evaluating the adequacy, efficiency, and equity of surface water distribution. Hydraulic simulation of water distribution system, as well as providing the information required for training and validation of the intelligent models, were performed using the HEC-RAS model. The results showed that compared to the FIS model, ANN and ANFIS models similarly predicted the model outputs with lower errors at almost the same level. The adequacy, efficiency, and equity indicators were predicted by ANFIS model with MAPE of 0.16, 0.01 and 0.23, respectively. Also, FIS model was only able to predict the efficiency and could not predict the adequacy and equity with appropriate performance. The findings of this study reveal that since the ANFIS model uses both FIS and ANN models in its structure, it considers the model uncertainty reliably, and it can be used to evaluate the performance of agricultural water systems.

Simulation and evaluation of agricultural water distribution and delivery systems with a Hybrid Bayesian network model

Regular appraisal performance of the irrigation water distribution systems from the adequacy, equity, and sustainable operation perspectives are essential due to the significant water losses that has been led by the improper adjustments of the hydraulic structures. Appropriate operational strategies could be adapted when the irrigation district authorities have a pragmatic approach to assess the hydraulic behavior of the system. This study develops an intelligent model for i) hydraulic simulation and ii) operational performance evaluation of the agricultural water distribution systems by employing a Hybrid Bayesian Networks (HBNs). The developed model was tested on a real test case located in Iran and under the different operational scenarios. In this regard, firstly, a hydrodynamic model of the test case was developed, calibrated, and validated to simulate the hydraulic condition of the irrigation canal based on a wide range of the canal inflow variations, called operational scenarios. Then, performance assessment was conducted for the scenarios based on adequacy, equity, and efficiency of water distribution perspectives. The results were employed for the training of the HBNs model. The HBNs model configuration was selected based on the irrigation district manages expectations, where the performance indicators of "adequacy," "efficiency" and "equity" of water delivery, needs to be calculated for the canal inflow variations in different operational scenarios. Validation of the developed HBNs model reveals that Mean Absolute Percentage Error (MAPE) and Coefficient of Determination (R2) of the superior model within the entire output nodes are 17.31% and 0.96, respectively. The results indicated the ability of the HBNs Model for the "Simulation/Performance Appraisal" of any operating systems in the irrigation districts. The developed model is a useful tool for i) periodic appraisal performance of the distribution system, ii) operational personals and ditch-riders, and iii) regionalization of the district to facilitate the recurrent inspections and field visiting.

Hybrid Model for Short-Term Water Demand Forecasting Based on Error Correction Using Chaotic Time Series

Short-term water demand forecasting plays an important role in smart management and real-time simulation of water distribution systems (WDSs). This paper proposes a hybrid model for the short-term forecasting in the horizon of one day with 15 min time steps, which improves the forecasting accuracy by adding an error correction module to the initial forecasting model. The initial forecasting model is firstly established based on the least square support vector machine (LSSVM), the errors time series obtained by comparing the observed values and the initial forecasted values is next transformed into chaotic time series, and then the error correction model is established by the LSSVM method to forecast errors at the next time step. The hybrid model is tested on three real-world district metering areas (DMAs) in Beijing, China, with different demand patterns. The results show that, with the help of the error correction module, the hybrid model reduced the mean absolute percentage error (MAPE) of forecasted demand from (5.64%, 4.06%, 5.84%) to (4.84%, 3.15%, 3.47%) for the three DMAs, compared with using LSSVM without error correction. Therefore, the proposed hybrid model provides a better solution for short-term water demand forecasting on the tested cases.

Effects of leakage points on intrusion volume in a simulated water distribution system

Abstract Contamination can intrude into urban water distribution systems through pipe leakage orifices or other deficiencies, which can create public health risks. Intrusion volume is a significant indicator of health risks when a pollution incident occurs. A pilot-scale platform was constructed to simulate the contamination intrusion through leakage holes caused by low or negative pressure events. The intrusion device was improved from the author's previous study by substituting the replaceable pipes in the main pipe for the side connecting pipe. Comparison between the two intrusion devices demonstrated that the intrusion device with the side connecting pipe may underestimate the intrusion volume. The orifice diameter range is extended to be 3–19.0 mm to analyze the effects of leakage sizes on the intrusion volume. The results show that the intrusion volume first increased and then decreased with increase of the orifice diameter. The calculated intrusion volume by the orifice discharge equation using the measured discharge coefficient is slightly different from the measured intrusion volume.

Benchmarking Study of Water Distribution System Solution Methods

AbstractIn recent years, a number of new water distribution system (WDS) solution methods have been developed. These methods have been aimed at improving the speed and reliability of WDS simulation...

Effects of Chloramine and Coupon Material on Biofilm Abundance and Community Composition in Bench-Scale Simulated Water Distribution Systems and Comparison with Full-Scale Water Mains.

The vast majority of bacteria in drinking water distribution systems (DWDSs) reside in biofilms on the interior walls of water mains. Little is known about how water quality conditions affect water-main biofilms because of the inherent limitations in experimenting with drinking water supplies and accessing the water mains for sampling. Bench-scale reactors permit experimentation and ease of biofilm sampling, yet questions remain as to how well biofilms in laboratory reactors represent those on water mains. In this study, the effects of DWDS pipe materials and chloramine residual on biofilms were investigated by cultivating biofilms on cement, polyvinyl chloride, and high density polyethylene coupons in CDC reactors for up to 28 months in the presence of chloraminated or dechlorinated tap water. The bench-scale biofilm microbiomes were then compared with the microbiome on a water main from the full-scale system that supplied the water to the reactors. The presence of a chloramine residual (1.74 ± 0.21 mg/L) suppressed biofilm accumulation and selected for Mycobacterium-like and Sphingopyxis-like operational taxonomic units (OTUs) while the destruction of the chloramine residual resulted in a significant increase in biomass quantity and a shift toward a more diverse community dominated by Nitrospira-like OTUs, which, our results suggest, may be complete ammonia oxidizers (comammox). Coupon material, however, had a relatively minor effect on the abundance and community composition of the biofilm bacteria. Although biofilm communities from the chloraminated water reactor and the water mains shared some dominant populations (namely, Mycobacterium- and Nitrosomonas-like OTUs), the communities were significantly different. This manuscript provides novel insights into the effects of dechlorination and pipe material on biofilm community composition. Furthermore, to our knowledge, it is the first study to compare biofilm in a tap water-fed, bench-scale simulated distribution system to biofilm on water mains from the full-scale system supplying the tap water.

Self‐Adaptive Calibration of Real‐Time Demand and Roughness of Water Distribution Systems

AbstractReal‐time simulation of water distribution systems (WDSs) has been applied to water resource problems ranging from engineering optimization design and operation planning and management. However, accurate implementation of real‐time simulation of WDS is still a challenging task due to the limited knowledge of the large amount of varying nodal demands and pipe characteristics over the entire network system. This paper presents a self‐adaptive calibration method based on Kalman filter (KF) that takes advantage of the long‐term monitoring data for dual calibration of nodal demands and pipe roughness. Inferential measurements are introduced to avoid linear assumptions of the WDS system and link the hydraulics of WDS with KF. Hence, it is able to employ KF to solve the nonlinear problems in looped water distribution network. By assimilating the long‐term monitoring data and adapting the calibrated parameters to various operating conditions, the framework can reduce the uncertainties caused by measurement errors and quantify the uncertainties by covariance matrixes. In addition, the presented method can help to identify abnormal WDS conditions. Three case studies have been conducted to illustrate the validity of the proposed method and its applications. The results have shown that the proposed framework is reliable and effective in practical applications.

Integrated multi-objective optimization framework for urban water supply systems under alternative climates and future policy

Abstract The sustainable implementation of an urban water supply system (UWSS) should achieve an optimum compromise among water ecosystem protection, climate change mitigation, and economic performance. This paper establishes an UWSS optimization framework by integrating a multi-objective optimization model with life cycle assessment and a water distribution system simulation model. The trade-offs among total cost, greenhouse gas (GHG) emission, and an extended water ecosystem impact (WII) objective are taken into consideration. The central area of Beijing City which is the main water-receiving area of the South-to-North Water Transfer Project (SNWTP), is chosen as a case study. A baseline scenario for 2012 and several future scenarios for 2020 and 2030 are implemented to investigate the influence of alternative climates and future policies on UWSS optimization. The outcome of this study indicates that the UWSS should be shifted towards an unconventional water-based supply system in the future. The share of contribution of the unconventional water supply is increased from 41% in 2012 to more than 70% in 2020 and 2030. This result can be drawn in all of the water-receiving areas of the middle route of the SNWTP. Moreover, alternative climates have influences on unconventional water utilization. Imported water through the middle route of the SNWTP is a preferable choice to augment the water supply in arid climates while reclaimed wastewater is more appropriate in moist climates. A decomposition analysis of the emissions reduction policies shows that the water demand control strategy is efficient in GHG emissions reduction while the water supply management strategy is efficient in WII reduction. Such a systematic analysis of an UWSS could provide sustainable and practical recommendations on water resource management in arid regions.

Advanced Hydroinformatic Techniques for the Simulation and Analysis of Water Supply and Distribution Systems

This document is intended to be a presentation of the Special Issue “Advanced Hydroinformatic Techniques for the Simulation and Analysis of Water Supply and Distribution Systems”. The final aim of this Special Issue is to propose a suitable framework supporting insightful hydraulic mechanisms to aid the decision-making processes of water utility managers and practitioners. Its 18 peer-reviewed articles present as varied topics as: water distribution system design, optimization of network performance assessment, monitoring and diagnosis of pressure pipe systems, optimal water quality management, and modelling and forecasting water demand. Overall, these articles explore new research avenues on urban hydraulics and hydroinformatics, showing to be of great value for both Academia and those water utility stakeholders.

Method for Extended Period Simulation of Water Distribution Networks with Pressure Driven Demands

This paper proposes a non-iterative method to perform the simulation of water distribution systems with pressure driven demands using EPANET2 without the need to use its programmer’s toolkit. The method works for single period simulation (snapshot) and for extended period simulation (EPS) as well. It is based on the addition of a flow control valve (FCV), a throttle control valve (TCV), a check valve (CV) and a reservoir to each demand node in the network, in addition to a list of simple controls to modify the setting of the FCV and TCV in each time step. The main advantages of this approach are: 1. the source code of EPANET2 is not modified, 2. the toolkit functions are not needed for the simulation and they remain available for further uses, 3. the extended period simulation (EPS) is performed by EPANET2 and it carries tank levels, demand variation and other time-changing variables internally. The performance of the method is tested in two benchmark networks and a real size network with pumps, tanks and a 24 h demand pattern. The results show that the method computed the pressures and outflows accurately and that the computational time required is not significantly higher than a demand driven execution in most cases.

Implications of the corrosion index for the quality of flowing tap water and the effects of added alkalinity on corrosion control

AbstractThree corrosion indices, Langelier saturation index (LSI), Ryznar index (RI) and calcium carbonate precipitation potential (CCPP), were determined to find whether the corrosive index of flowing tap water could indicate the quality of the water that corresponded to the calculated index value. Water samples were collected from tap water distribution pipe in buildings of Kangwon National University, Korea. Correlations among the LSI, RI and CCPP were also investigated. The effects of alkalinity addition using lime and carbon dioxide on the progress of corrosion were examined in a laboratory‐scale simulated water distribution system (SWDS) for 5 months. In the SWDS study, corrosion rate in flowing tap waters was retarded by 12% with the alkalinity addition. The results of the current study confirmed that the corrosion indices are not always the best indicators to predict the quality of the flowing tap water.

A Toolkit for Water Distribution Systems’ Simulation Using the Loop Method and High Performance Computing

This paper presents an Epanet-compatible toolkit for water distribution systems’ (WDS) simulation that uses the looped Newton-Raphson simulation method in combination with High Performance Computing (HPC) to harness the computational power of current multicore processors. The toolkit enables substantial reduction in computing time with respect to Epanet, especially important if we take into account that during the last 20 years no code for water distribution systems’ simulation (WDS) has significantly outperformed Epanet's computational algorithms. The development of the toolkit required overcoming some difficulties arising in the context of the loop method, and also applying HPC to selected tasks within the simulation.