scholarly journals Assessment and modelling of residual chlorine in water supply systems: The case of Dangila Town, Ethiopia

2020 ◽  
Vol 1 (1) ◽  
pp. 19-26
Author(s):  
Teka Girmay ◽  
Wondwesen Tesfaye Semagn ◽  
Eusman Ebrahim Shumey ◽  
Mariye Majo Shute ◽  
Atikilt Abebe Ketema
Keyword(s):  
Water Supply ◽  
Flow Rate ◽  
Distribution System ◽  
Water Security ◽  
Chlorine Concentration ◽  
Residual Chlorine ◽  
Water Supply Systems ◽  
Injection Point ◽  
Secondary Sources ◽  
Dangila Town

Application of chlorine for drinking water security in the water supply distribution network for the Dangila town is not well managed. The study was conducted by the help of Water CAD software to evaluate the chlorine dosing and residual chlorine model. The necessary data were taken from primary and secondary sources. Three scenarios were developed for modelling the residual chlorine content in the distribution system. Two scenarios were produced with chlorine dose of 0.6 mg/l at a flow rate of 26 ml/s and chlorine dose of 0.5 mg /l at a flow rate of 22 ml/s, respectively. Residual chlorine concentration above normal limits (0.5 mg/l) was recorded in both scenarios around the injection point whereas four sample points were below 0.2 mg/l. Scenario II, all residual chlorine values were lower than 0.5 mg/l but still lower than 0.2 mg/l at the farthest four sampling points.  In order to solve the above problem, A third scenario was developed with three reservoir injection points, Junction 4 and 55'' within 0.45, 0.15 and 0.2 mg/l of chlorine in order to maintain appropriate residual chlorine concentration.  Hence, the best solution identified from the analysis was the installation of two additional chlorine injection points.

scholarly journals Application of model fitting technique to enhance bacterial regrowth potential (BRP) measurement for drinking water supply monitoring

2021 ◽  
Author(s):  
Wenjin Xue ◽  
Christopher W. K. Chow ◽  
John van Leeuwen
Keyword(s):  
Drinking Water ◽  
Water Supply ◽  
Water Samples ◽  
Distribution System ◽  
Distribution Systems ◽  
Tap Water ◽  
Treatment Plant ◽  
Drinking Water Supply ◽  
Water Supply Systems ◽  
Bacterial Regrowth

Abstract The bacterial regrowth potential (BRP) method was utilised to indirectly measure the assimilable organic carbon (AOC) as an indicator for the assessment of the microbial regrowth potential in drinking water distribution systems. A model using various microbial growth parameters was developed in order to standardise the experimental interpretation for BRP measurement. This study used 82 experimental BRP data sets of water samples collected from the water treatment plant to locations (customer taps) in the distribution system. The data were used to model the BRP process (growth curve) by a data fitting procedure and to obtain a best-fitted equation. Statistical assessments and model validation for evaluating the equation obtained by fitting these 82 sets of data were conducted, and the results show average R2 values were 0.987 for treated water samples (collected at the plant prior to chlorination) and 0.983 for tap water (collected at the customer taps). The F values obtained from the F-test are all exceeded their corresponding F critical values, and the results from the t-test also showed a good outcome. These results indicate this model would be successfully applied in modelling BRP in drinking water supply systems.

scholarly journals Modeling Study of Design Flow Rates for Cascade Water Supply Systems in Residential Skyscrapers

Water ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2580
Author(s):  
Yang Zhou ◽  
Eric Lee ◽  
Ling-Tim Wong ◽  
Kwok-Wai Mui
Keyword(s):  
Water Supply ◽  
Mathematical Models ◽  
Flow Rate ◽  
Supply System ◽  
Water Supply System ◽  
Design Flow ◽  
Water Volume ◽  
Water Supply Systems ◽  
Supply Systems ◽  
Design Flow Rate

Skyscrapers are common nowadays around the world, especially in cities with limited development area. In order to pump water up to the higher level of a skyscraper, a cascade water supply system has to be installed. Currently, cascade water supply systems are mainly designed based on practical experiences or requirements of existing standards/guidelines that, in fact, are not specifically for skyscrapers. However, thorough studies on cascade water supply system designs are still limited in the literature. This study proposes mathematical models and uses Monte Carlo simulations to evaluate the design flow rate of a typical cascade water supply system that feeds various appliances in a residential skyscraper in Hong Kong. Graphs that showed the correlations between the inflow rate in the supply pipe and water volume in the tank are obtained. While tank storage volume is confirmed, the design flow rate of the cascade water supply system can be determined from these graphs. The proposed mathematical models can also be applied to evaluate the design flow rate of cascade water supply systems in other types of skyscrapers (e.g., office, commercial building) as well as with the changes in water demand patterns in the models.

Investigating disinfectant by-products in Harare potable water supply, Zimbabwe

2018 ◽  
Vol 8 (3) ◽  
pp. 415-428 ◽  
Author(s):  
Kuitakwashe Nhongo ◽  
Zvikomborero Hoko ◽  
Jameson Kugara
Keyword(s):  
Water Supply ◽  
Environmental Protection Agency ◽  
Distribution System ◽  
Water Distribution ◽  
The United States ◽  
World Health ◽  
Residual Chlorine ◽  
By Products ◽  
Trihalomethanes Formation

Abstract Formation of disinfectant by-products was investigated in the Harare water supply system from February to April 2015. Sampling sites were selected from the lake, Morton Jaffray Water Treatment Works and critical points in the distribution system. The spatial variations of trihalomethanes and selected water quality parameters were investigated for 15 sampling points in 5 sampling campaigns to assess suitability for drinking. All trihalomethane species were measured, namely chloroform, bromodichloromethane, dibromochloromethane and bromoform. Only chloroform and bromodichloromethane were detected. The study confirmed that there is trihalomethanes formation in the Harare water distribution system and that it is affected by the residence time and presence of organic matter in the system. However, the levels of trihalomethanes are generally within the levels suggested by the World Health Organization. Only bromodichloromethane presents a risk for long-term exposure as it had levels that exceeded the limit for long-term exposure suggested by the United States Environmental Protection Agency. Bromodichloromethane, turbidity and free residual chlorine levels were not suitable for drinking in some of the zones. Boosting of chlorine residuals is necessary especially in areas with free chlorine less than 0.2 mg/L. Injection of ammonia, periodic cleaning of storage reservoirs, and flushing of lines will reduce trihalomethanes formation.

scholarly journals Burst Detection in Water Distribution Systems: The Issue of Dataset Collection

2020 ◽  
Vol 10 (22) ◽  
pp. 8219
Author(s):  
Andrea Menapace ◽  
Ariele Zanfei ◽  
Manuel Felicetti ◽  
Diego Avesani ◽  
Maurizio Righetti ◽  
...  
Keyword(s):  
Water Supply ◽  
Water Consumption ◽  
Distribution System ◽  
Smart Grids ◽  
Distribution Systems ◽  
Water Distribution ◽  
Stochastic Modelling ◽  
Water Supply Systems ◽  
Consumption Data ◽  
Supply Systems

Developing data-driven models for bursts detection is currently a demanding challenge for efficient and sustainable management of water supply systems. The main limit in the progress of these models lies in the large amount of accurate data required. The aim is to present a methodology for the generation of reliable data, which are fundamental to train anomaly detection models and set alarms. Thus, the results of the proposed methodology is to provide suitable water consumption data. The presented procedure consists of stochastic modelling of water request and hydraulic pipes bursts simulation to yield suitable synthetic time series of flow rates, for instance, inlet flows of district metered areas and small water supply systems. The water request is obtained through the superimposition of different components, such as the daily, the weekly, and the yearly trends jointly with a random normal distributed component based on the consumption mean and variance, and the number of users aggregation. The resulting request is implemented into the hydraulic model of the distribution system, also embedding background leaks and bursts using a pressure-driven approach with both concentrated and distributed demand schemes. This work seeks to close the gap in the field of synthetic generation of drinking water consumption data, by establishing a proper dedicated methodology that aims to support future water smart grids.

scholarly journals Energy efficiency of multi-apartment residential houses with individual heat supply

2020 ◽  
Vol 212 ◽  
pp. 01011
Author(s):  
Vladimir Melnikov ◽  
Uladzimir Navaseltsau ◽  
Dzina Navaseltsava
Keyword(s):  
Water Supply ◽  
Flow Rate ◽  
Thermal Energy ◽  
Water System ◽  
Hot Water ◽  
Water Supply Systems ◽  
Hydraulic Systems ◽  
Circulation Mode ◽  
Hot Water Supply ◽  
Internal Networks

Centralized hot water systems widely used in Russia and Belarus are characterized by a considerable length and branching which inevitably leads to increased heat losses and to an unstable hydraulic system. The operation of the domestic hot water system in the circulation mode can be characterized by several parameters; one of which is the specific ratio of the cost of thermal energy for heating a cubic meter of hot water. The parameter is often regulated by law in Russia; exceeding this parameter is considered as administrative violation. The aim of the research is to determine the design and actual costs of thermal energy for hot water supply (hot water heating) and their comparison, analysis of the data obtained. The methodology for determining the design and real costs of thermal energy for hot water supply was to study the operation of the hot water supply system of a residential 144-apartment 9-storey building. The research showed that the actual circulating flow rate is much less than the calculated circulating flow rate. The authors note that in order to optimize the standard for heating a cubic meter of water it is necessary to observe the calculated circulation modes. This will require stabilization of the hydraulic systems of both the external and internal networks which is a difficult but feasible task. The research results are supposed to be taken into account when setting up existing hot water supply systems.

scholarly journals Design and Analysis of Rural Water Supply System Using Loop 4.0 and Water Gems V8i for Nava Shihora Zone 1

2019 ◽  
Vol 9 (1) ◽  
pp. 2258-2266
Keyword(s):  
Water Supply ◽  
Distribution System ◽  
Water Distribution ◽  
Water Distribution System ◽  
Extended Period ◽  
Supply System ◽  
Water Supply System ◽  
Residual Chlorine ◽  
Residual Pressure ◽  
Rural Water

The study presents the hydraulic design and analysis of Rural Water Distribution System (WDS) for Nava shihora region of zone 1 of the state of Gujarat, India. Water supply distribution system is designed for this study for population estimated for future 30 years. LOOP 4.0 and Water Gems v8i software have been used and the results are compared to determine the economical size of pipes for water distribution system. The economical size of pipes of water supply distribution system is designed by considering the constraints; residual pressure at each node, velocity of flow in pipe, head loos in pipes, material of pipes, elevated service reservoir level, peak factor and available commercial pipe diameters. Further water distribution system has been analyzed for extended period simulation (EPS) for the present population scenario for intermittent water supply using Water Gems v8i. Further water supply system is analyzed the residual chlorine concentration at nodes and in the pipe links and also the total cost of water supply system of rural region is estimated.

scholarly journals Network Model Analysis of Residual Chlorine to Reduce Disinfection Byproducts in Water Supply Systems in Yangon City, Myanmar

Water ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 2921
Author(s):  
Nwe Nwe Zin ◽  
Shinobu Kazama ◽  
Satoshi Takizawa
Keyword(s):  
Water Quality ◽  
Water Supply ◽  
Tap Water ◽  
Water Quality Monitoring ◽  
Disinfection Byproducts ◽  
Residual Chlorine ◽  
Water Supply Systems ◽  
Formation Kinetics ◽  
Chlorine Decay ◽  
Supply Systems

In Yangon City, chlorination commenced in January 2020 to supply drinkable water; therefore, there is as yet no information on chlorine decay and DBP formation in the water supply system. This study aimed to find methods to optimize chlorine dosage in Yangon City. Onsite sampling and laboratory analyses of residual chlorine and trihalomethane (THM) formation, as well as water quality simulations, were conducted to find the chlorine decay and THM formation kinetics. Due to a high chlorine dose of 2 mg/L for both pre- and post-chlorination, disinfection was effective despite the low removal efficiency of turbidity. However, THMs were found in high levels in both treated and tap water due to the high THM formation potential of raw water. The re-contamination and/or transformation of dissolved organic matter were found in the distribution network by increases in specific ultraviolet absorption (SUVA) values and excitation-emission matrix (EEM) fluorophores, which brought about variations of THMs in the networks. The EPANET models were run assuming there to be no water leakages; it was found that the chlorine dose could be decreased to 0.8 mg/L to meet the guidelines for THMs and residual chlorine. The methods employed in this study could be also applied in other water supply systems in tropical developing countries with limited water quality monitoring data.

Determination of Neutral Point in Water Distribution Network Pipes with Variable Discharge on Route

2014 ◽  
Vol 909 ◽  
pp. 428-432 ◽  
Author(s):  
Ioan Sarbu ◽  
Gabriel Ostafe
Keyword(s):  
Water Supply ◽  
Distribution System ◽  
Water Distribution ◽  
Distribution Network ◽  
Water Distribution Network ◽  
Distribution Networks ◽  
Neutral Point ◽  
Water Supply Systems ◽  
Proposed Model

Distribution networks are an essential part of all water supply systems. Distribution system costs within any water supply scheme may be equal to or greater than 60% of the entire cost of the project. The reliability of supply is much greater in the case of looped networks. The pipe networks have concentrated outflows or uniform outflow along the length of each pipe. In some pipes with variable discharge of a looped distribution network, water velocity could be reversed between its extremities. Thus, it is a water stall point denominated neutral point in which the discharge is null. In this paper a mathematical model for the determination of water stall point location in the pipes with distributed consumption is developed. This model has been implemented in a computer program for PC microsystems. Numerical example will be presented to demonstrate the accuracy and efficiency of the proposed model.

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