scholarly journals Experimental Investigation of Purging Saline Solution from a Dead-End Water Pipe

Water ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 994
Author(s):  
Mohamed Elgamal ◽  
Mohamed Farouk

Salty groundwater might find its way into dead end legs of a water distribution network and thus efforts are required to clean such parts of the network. This paper reports, for the first time, the results of a visual study for laboratory experimental investigation on the purging process of saline water from a dead-end water pipe using fresh water. Three purging locations and a number of purging flow rates were considered to identify the effect of purging location and purging flow rate on the time required to completely remove saline water from the dead-end pipe. Image processing analysis techniques were used to capture data from the experimental lab setup. A universal gray-intensity to salinity curve was experimentally found to formulate a color intensity to salinity mapping. A script code based on Octave numerical package was written for this regard to determine the temporal variation of the total dissolved salt (TDS) value within the dead leg pipe. It is generally noted that, as Reynolds number gets higher, the time removal ratio (t/ts) gets bigger. It is also noted that, as a purging location gets farther from the dead end, the time required for the complete removal of TDS increases exponentially.

2008 ◽  
Vol 8 (4) ◽  
pp. 421-426
Author(s):  
J. Menaia ◽  
M. Benoliel ◽  
A. Lopes ◽  
C. Neto ◽  
E. Ferreira ◽  
...  

Concerns arise from the possible occurrence of pathogens in drinking water pipe biofilms and storage tank sediments. In these studies, biofilm samples from pipes and sediments from storage tanks of the Lisbon drinking water distribution system were analyzed. Protein determinations and heterotrophic counts on pipe biofilm samples were used to assess the Lisbon network sessile colonization intensity and distribution. Indicator and pathogenic microorganisms were analyzed in pipe biofilm samples, as well as in storage tanks biofilm and sediments, by using cultural methods and PCR, to assess risks. Results have shown that the Lisbon network sessile colonization is relatively weak in intensity. In addition, no meaningful hazards were apparent for both the network biofilm and the storage tanks biofilm and sediments.


Author(s):  
A L Muller ◽  
O J Gericke ◽  
J P J Pietersen

This paper presents the development of a methodological approach based on the integration of free-of-charge open-source software, e.g. QGIS and EPANET, and engineering practices applicable to water distribution network design. The use of QGIS and EPANET, as well as the integration thereof with sound engineering practices and judgement, proved to be both viable and practical to enable practitioners to create a water distribution network model of an existing network in smaller developments or towns. Typically, in the latter smaller developments or towns, the professional cost associated with the additional time required when commercial licensed software is used, could be lower than the actual cost associated with the procurement of the licensed software itself. Hence, the developed process flow diagrams will not only potentially save time and money in comparison to a traditional, manual approach in EPANET, but will also provide guidance to practitioners and assist smaller municipalities in southern Africa facing challenges in terms of outdated records and budget constraints. It is envisaged that the implementation of the overall methodology will contribute to improved water infrastructure planning, design and management, especially in the southern African context where water resources are scarce and service delivery remains a pressing issue.


2008 ◽  
Vol 3 (2) ◽  
Author(s):  
Jayong Koo ◽  
Toyono Inakazu ◽  
Akira Koizumi ◽  
Yasuhiro Arai ◽  
Kyoungpil Kim ◽  
...  

It is difficult to estimate residual chlorine at the dead-end area of the water distribution network because chlorine consumption is influenced by various factors. Therefore, there are many water utilities that control the amounts of chlorine in reservoirs using empirical trial-and-error methods to maintain safe levels of residual chlorine in the distribution system. In this study, an ANN model of residual chlorine concentration is proposed which could be used to reduce in chlorine use in water distribution system. The ANN model with best performance was selected by training and verification. The five scenarios for the reduction in chlorine use were analyzed by setting the input chlorine as low as 0.05~0.25 mg/L compared with the input chlorine observed in the time series. Case 4 is the best to be satisfied with the input condition (0.4 mg/L or more) and output condition (0.34 mg/L or more) at the same time. It is possible to reduce chlorine in use up to 0.2 mg/L in the maximum amount.


2021 ◽  
Vol 13 (4) ◽  
pp. 2310
Author(s):  
Lim Jen Nee Jones ◽  
Daniel Kong ◽  
Boon Thong Tan ◽  
Puspavathy Rassiah

Reducing non-revenue water (NRW) within a water distribution network may lead to significant water savings. Most existing literature tend to focus on the design and implementation aspects of NRW loss through better management of leaks, reservoir overflow, and water theft. In contrast, this paper examines the association between the various water pipe types and their respective impact on NRW loss in an emerging country. Malaysia is currently listed under emerging and developing economies category in the International Monetary Fund World Economic Outlook Database (October 2020). A correlation analysis is carried out using historical data obtained from the Malaysian water authority, covering fiscal years 2013 to 2017 (inclusive of both years). Further analysis is carried out by measuring the number of cases reported for two selected states in relation to the type of pipe materials used. Results show that there is a significant correlation between mild steel and polyethylene pipes to NRW loss. This study provides a better understanding of how water pipe types affect NRW loss, which is pertinent to developing best practices in the marketplace to manage NRW loss and protect water resources.


Proceedings ◽  
2019 ◽  
Vol 48 (1) ◽  
pp. 20
Author(s):  
Stefania Avvedimento ◽  
Sara Todeschini ◽  
Carlo Giudicianni ◽  
Armando Di Nardo ◽  
Tom Walski ◽  
...  

Flushing plans within a water distribution network (WDN) provide a tool for improving disinfectant residuals and removing stagnant water. The problem of low disinfectant residuals occurs in areas of a WDN such as dead-end nodes, in which low flow conditions and long residence times lead to excessive decay of the disinfectant upstream from users. Here, a methodology is presented to maintain adequate disinfectant residuals in WDNs that have numerous dead-end nodes. The slight increase in nodal outflows at these sites, which can be obtained through the opening of a blow-off at the hydrant site, can help in tackling this problem. The methodology is based on the combined use of optimization and of flow routing/water quality modelling. The concentration of disinfectant at the source(s) and the values of nodal emitter coefficients at the critical dead-end nodes are the decisional variables to be optimized. Two objective functions are considered in the optimization, namely the total volume of water delivered in the network and the total mass of disinfectant injected into the network. The effectiveness of the methodology is proven on a real WDN, yielding an insight into the economic feasibility of the solution.


2016 ◽  
Vol 17 (1) ◽  
pp. 246-258 ◽  
Author(s):  
R. K. Chowdhury ◽  
M. A. Rajput

Reuse of recycled wastewater is one of the most feasible unconventional urban water sources in the United Arab Emirates (UAE). The extraction and reuse of greywater might affect the water and sewer pipe networks by changing flow characteristics. Therefore, the research question is how much greywater can be reused without affecting the existing water and sewer pipe networks? A residential complex located in Al Ain, UAE, was investigated in this regard. Water pipe network, water consumption and sewer flow data were collected and scenario modelling was conducted using the EPANET software. It was found that 100% capture and reuse of greywater has no impact on the upstream water distribution network, but reduces the recommended design flow in the downstream sewer network. The modelling results show that about 50% of generated greywater (about 95 litres per capita per day) can be harvested without affecting the upstream and downstream water and sewer flow characteristics, respectively.


2017 ◽  
Vol 16 (5) ◽  
pp. 1071-1079 ◽  
Author(s):  
Andrei-Mugur Georgescu ◽  
Sanda-Carmen Georgescu ◽  
Remus Alexandru Madularea ◽  
Diana Maria Bucur ◽  
Georgiana Dunca

Sign in / Sign up

Export Citation Format

Share Document