scholarly journals Rechlorination for residual chlorine concentration equalization in distribution system

2014 ◽  
Vol 28 (1) ◽  
pp. 91-101 ◽  
Author(s):  
Jinkeun Kim ◽  
Ji-An Han
Keyword(s):  
Distribution System ◽  
Chlorine Concentration ◽  
Residual Chlorine

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 Optimization of a Water Distribution System in Kenya

2019 ◽  
Vol 9 (1) ◽  
pp. 1334-1337
Keyword(s):  
Distribution System ◽  
Water Distribution ◽  
Water Distribution System ◽  
Supply System ◽  
Chlorine Concentration ◽  
Quality Analysis ◽  
Residual Chlorine ◽  
Study Results ◽  
Minimum Requirements ◽  
Feasible Solutions

Supplying water in significant quality and quantity is still a challenge for developing countries. Juja water distribution system located in Kenya faces low-pressure and inadequate residual chlorine concentration challenges and requires capacity boosting to meet the minimum requirements of a water supply system. For optimizing the existing Juja distribution network, the current study proposes some feasible solutions. The solutions comprise of network repairs, recommissioning of an existing tank coupled with a system of chlorine booster points, an addition of a booster pump and, changes in diameters of some pipes. The analysis was carried out using Epanet 3.0 hydraulic model. The hydraulic capacity of the upgraded network met the minimum requirements of a distribution system. Pressures in the distribution system ranged between 16.91 m to 63.63 m at user points after optimization with acceptable maximum headloss of 18.24 m/km and velocity of 2.25 m/s. The hydraulic behavior of the network satisfied general guidelines. The water quality analysis showed reasonable residual chlorine concentration, with 95% of the supply area ranging between 0.40 and 0.60 mg/l after upgrade by the model. These study results were recommended and shared with the Juja water company, which is currently undertaking a review process of the supply system.

Application of two approaches to model chlorine residuals in Severn Trent Water Ltd (STW) distribution systems

1997 ◽  
Vol 36 (5) ◽  
pp. 317-324 ◽  
Author(s):  
M.J. Rodriguez ◽  
J.R. West ◽  
J. Powell ◽  
J.B. Sérodes
Keyword(s):  
Distribution System ◽  
Distribution Systems ◽  
Treatment Plant ◽  
Residual Chlorine ◽  
Ann Model ◽  
Order Model ◽  
First Order ◽  
Chlorine Decay ◽  
Artificial Neural Network Ann ◽  
Key Parameter

Increasingly, those who work in the field of drinking water have demonstrated an interest in developing models for evolution of water quality from the treatment plant to the consumer's tap. To date, most of the modelling efforts have been focused on residual chlorine as a key parameter of quality within distribution systems. This paper presents the application of a conventional approach, the first order model, and the application of an emergent modelling approach, an artificial neural network (ANN) model, to simulate residual chlorine in a Severn Trent Water Ltd (U.K.) distribution system. The application of the first order model depends on the adequate estimation of the chlorine decay coefficient and the travel time within the system. The success of an ANN model depends on the use of representative data about factors which affect chlorine evolution in the system. Results demonstrate that ANN has a promising capacity for learning the dynamics of chlorine decay. The development of an ANN appears to be justifiable for disinfection control purposes, in cases when parameter estimation within the first order model is imprecise or difficult to obtain.

scholarly journals First Derivative UV Spectra of Surface Water as a Monitor of Chlorination in Drinking Water Treatment

2001 ◽  
Vol 1 ◽  
pp. 39-43 ◽  
Author(s):  
V. Zitko
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Surface Water ◽  
Distribution System ◽  
Drinking Water Treatment ◽  
Uv Spectra ◽  
Free Chlorine ◽  
Residual Chlorine ◽  
First Derivative ◽  
Derivative Spectra

Many countries require the presence of free chlorine at about 0.1 mg/l in their drinking water supplies. For various reasons, such as cast-iron pipes or long residence times in the distribution system, free chlorine may decrease below detection limits. In such cases it is important to know whether or not the water was chlorinated or if nonchlorinated water entered the system by accident. Changes in UV spectra of natural organic matter in lakewater were used to assess qualitatively the degree of chlorination in the treatment to produce drinking water. The changes were more obvious in the first derivative spectra. In lakewater, the derivative spectra have a maximum at about 280 nm. This maximum shifts to longer wavelengths by up to 10 nm, decreases, and eventually disappears with an increasing dose of chlorine. The water treatment system was monitored by this technique for over 1 year and changes in the UV spectra of water samples were compared with experimental samples treated with known amounts of chlorine. The changes of the UV spectra with the concentration of added chlorine are presented. On several occasions, water, which received very little or no chlorination, may have entered the drinking water system. The results show that first derivative spectra are potentially a tool to determine, in the absence of residual chlorine, whether or not surface water was chlorinated during the treatment to produce potable water.

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.

Laboratory testing protocol to identify critical factors in bacterial compliance monitoring

2003 ◽  
Vol 47 (3) ◽  
pp. 131-136
Author(s):  
M. Abbaszadegan ◽  
P. Ghatpande ◽  
J. Brereton ◽  
A. Alum ◽  
R. Narasimhan
Keyword(s):  
Distribution System ◽  
Membrane Filtration ◽  
Bacterial Count ◽  
The Other ◽  
Residual Chlorine ◽  
First Flush ◽  
Sample Collection ◽  
Service Line ◽  
Bacterial Counts ◽  
Representative Sampling

This research focused on providing guidelines for water utilities on the collection and handling of routine bacteriological samples and in developing scientifically-based approaches in selecting the most representative sampling locations. A laboratory-scale pilot distribution system was designed comprising two parallel loops, one using unlined cast-iron pipe and one using PVC pipe. Each loop contained six sampling ports, including (1) a distribution main dead end faucet, (2) one long (5.5 m; 18 feet) and (3) one short (0.3 m; 1 foot) household copper service line with threaded hose-bibb taps, (4) one hose-bibb with welded faucet, (5) one dedicated sampling port (modeled after a manufacturer’s specifications) and (6) one laboratory-style (PVC) stop-cock sampling port. Residual chlorine concentrations were maintained at 0, 0.5, 1.5 and 2.0 mg/L stages during the course of the experiment. Bacterial samples were collected from the different sampling ports and assayed by membrane filtration and/or spread plate. Nutrient and R2A agars were used for heterotrophic plate counts (HPC), m-Endo agar for total coliform (TC) counts and Chromocult agar for injured bacterial analyses. Several methods of sample collection were tested using various combinations of flushing and tap disinfection, including “first flush” (no flushing, without tap disinfection), flushing only, tap disinfection only (using alcohol or hypochlorite solution) and flushing coupled with tap disinfection. The results indicated that the bacterial counts in samples drawn from dead ends were not significantly different from counts in samples from the other sample port configurations. First flush samples consistently produced the highest bacterial count results. Bacterial counts in samples from the long household copper service line were typically three orders of magnitude higher than in samples from the other sample ports. Thus, there is evidence that long copper household service connections may be unsuitable sample tap configurations for collecting samples intended to represent microbial quality in the distribution system.

scholarly journals Study on the Estimation of the Residual Chlorine Concentration in the Seismic Water Storage Tank

2016 ◽  
Vol 72 (6) ◽  
pp. II_177-II_185
Author(s):  
Keiji KISHIMOTO ◽  
Toyono INAKAZU ◽  
Akira KOIZUMI ◽  
Koichi HASEGAWA ◽  
Testuo HATANAKA ◽  
...  
Keyword(s):  
Storage Tank ◽  
Water Storage ◽  
Chlorine Concentration ◽  
Residual Chlorine ◽  
Water Storage Tank
Sign in / Sign up

Export Citation Format

Share Document