Evaluating Functional Coupling in Aeration Basin Air Distribution Systems

2015 ◽  
Author(s):  
Vigain Harutunian ◽  
Anne Harutunian ◽  
Kegham A. Harutunian ◽  
Shant Harutunian
Keyword(s):  
Distribution System ◽  
Distribution Systems ◽  
Guide Vane ◽  
Treatment Plant ◽  
Inlet Guide Vane ◽  
Functional Coupling ◽  
Independence Axiom ◽  
Functional Domain ◽  
Design Alternatives ◽  
System Designs

Axiomatic Design provides a set of axioms and corollaries to help make system design decisions. In this paper, the independence axiom is applied to evaluate alternate low pressure air (LPA) distribution system designs to serve the aeration basins of a wastewater treatment plant. The airflow to each air zone is defined as a functional requirement (FR) in the functional domain. A design parameter (DP) in the physical domain is selected to achieve each FR. The DPs include the LPA motor operated valve (MOV) damper positions and a process air blower inlet guide vane (IGV) position. Three design alternatives are developed and evaluated with the respect to the independence axiom. Each subsequent alternative attempts to reduce the amount of functional coupling. Reduced functional coupling in an LPA system results in a more stable treatment process and greater system longevity through reduced component wear.

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 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.

Poor efficacy of residual chlorine disinfectant in drinking water to inactivate waterborne pathogens in distribution systems

1999 ◽  
Vol 45 (8) ◽  
pp. 709-715 ◽  
Author(s):  
Pierre Payment
Keyword(s):  
Escherichia Coli ◽  
Drinking Water ◽  
Clostridium Perfringens ◽  
Water Samples ◽  
Distribution System ◽  
Distribution Systems ◽  
Treatment Plant ◽  
Epidemiological Studies ◽  
Residual Chlorine ◽  
Residual Concentration

To evaluate the inactivating power of residual chlorine in a distribution system, test microorganisms (Escherichia coli, Clostridium perfringens, bacteriophage phi-X 170, and poliovirus type 1) were added to drinking water samples obtained from two water treatment plants and their distribution system. Except for Escherichia coli, microorganisms remained relatively unaffected in water from the distribution systems tested. When sewage was added to the water samples, indigenous thermotolerant coliforms were inactivated only when water was obtained from sites very close to the treatment plant and containing a high residual chlorine concentration. Clostridium perfringens was barely inactivated, suggesting that the most resistant pathogens such as Giardia lamblia, Cryptosporidium parvum, and human enteric viruses would not be inactivated. Our results suggest that the maintenance of a free residual concentration in a distribution system does not provide a significant inactivation of pathogens, could even mask events of contamination of the distribution, and thus would provide only a false sense of safety with little active protection of public health. Recent epidemiological studies that have suggested a significant waterborne level of endemic gastrointestinal illness could then be explained by undetected intrusions in the distribution system, intrusions resulting in the infection of a small number of individuals without eliciting an outbreak situation.Key words: drinking water, chlorine, disinfection, pathogens, distribution system.

Disinfection byproduct formation kinetics of a water treatment plant on Kinmen Island

2015 ◽  
Vol 15 (6) ◽  
pp. 1200-1206
Author(s):  
Hsien-chun Ke ◽  
Hsin-hsin Tung
Keyword(s):  
Distribution System ◽  
Distribution Systems ◽  
Organic Nitrogen ◽  
Treatment Plant ◽  
Nitrogen Sources ◽  
Water Treatment Plant ◽  
Disinfection Byproduct ◽  
Formation Kinetics ◽  
Simulated Distribution ◽  
Byproduct Formation

Chloramine has often been used as a chlorine alternative for trihalomethane (THM) and haloacetic acid (HAA) control. However, nitrogenous disinfection byproduct (N-DBP) formation and nitrification in distribution have always been major concerns in chloramination practices. On Kinmen Island, the high organic nitrogen content in raw water may increase the nitrogenous DBP formation. Simulated distribution system tests were conducted to explore the DBP formation kinetics in the distribution system. Lower haloacetonitrile (HAN4) formation (0.26 μg L−1) with chloramination than with chlorination (10.48 μg L−1) was observed from the 24 hours of reaction time. The nitrogen sources contributing to the dichloroacetonitrile (DCAN) formation kinetics were explored with 15N-chloramination. The results showed that nitrogen sourced from organic nitrogen was more dominant in DCAN formation with low chloramine dosage. This suggests that chloramine contributes to less DCAN formation in practice, especially for short distribution systems. In summary, the results provide evidence that simultaneous post-chloramination and pre-chlorination would be a feasible disinfection strategy applied to control regulated THM and HAA formation on Kinmen Island.

scholarly journals Persistence of Nontuberculous Mycobacteria in a Drinking Water System after Addition of Filtration Treatment

2006 ◽  
Vol 72 (9) ◽  
pp. 5864-5869 ◽  
Author(s):  
Elizabeth D. Hilborn ◽  
Terry C. Covert ◽  
Mitchell A. Yakrus ◽  
Stephanie I. Harris ◽  
Sandra F. Donnelly ◽  
...  
Keyword(s):  
Drinking Water ◽  
Distribution System ◽  
Distribution Systems ◽  
Water Distribution ◽  
Cold Water ◽  
Nontuberculous Mycobacteria ◽  
Treatment Plant ◽  
Water System ◽  
Drinking Water Treatment ◽  
Drinking Water System

ABSTRACT There is evidence that drinking water may be a source of infections with pathogenic nontuberculous mycobacteria (NTM) in humans. One method by which NTM are believed to enter drinking water distribution systems is by their intracellular colonization of protozoa. Our goal was to determine whether we could detect a reduction in the prevalence of NTM recovered from an unfiltered surface drinking water system after the addition of ozonation and filtration treatment and to characterize NTM isolates by using molecular methods. We sampled water from two initially unfiltered surface drinking water treatment plants over a 29-month period. One plant received the addition of filtration and ozonation after 6 months of sampling. Sample sites included those at treatment plant effluents, distributed water, and cold water taps (point-of-use [POU] sites) in public or commercial buildings located within each distribution system. NTM were recovered from 27% of the sites. POU sites yielded the majority of NTM, with >50% recovery despite the addition of ozonation and filtration. Closely related electrophoretic groups of Mycobacterium avium were found to persist at POU sites for up to 26 months. Water collected from POU cold water outlets was persistently colonized with NTM despite the addition of ozonation and filtration to a drinking water system. This suggests that cold water POU outlets need to be considered as a potential source of chronic human exposure to NTM.

Analysis and viability of microturbines in hydraulic networks: a case study

2019 ◽  
Vol 68 (6) ◽  
pp. 474-482
Author(s):  
Ángel Mariano Rodríguez-Pérez ◽  
Inmaculada Pulido-Calvo
Keyword(s):  
Distribution System ◽  
Distribution Systems ◽  
Water Distribution ◽  
Recovery Period ◽  
Treatment Plant ◽  
Conservation Equation ◽  
Public Enterprise ◽  
Francis Turbine ◽  
Pressurized Water ◽  
Hydraulic Networks

Abstract The purpose of this study is to examine the use of hydraulic microturbines to make the most of the hydraulic energy available in pressurized water distribution systems. The study was carried out on suitable points of pressurized hydraulic networks, which are managed by Giahsa, a public enterprise responsible for the management of the municipal communities of services (MAS) in the province of Huelva, southwestern Spain. The distribution system situated between the Cabeza del Pasto reservoir in the Andévalo area (Huelva, Spain) and the wastewater treatment plant (WWTP) in the municipality of Puebla de Guzmán (Huelva, Spain) was examined. To obtain the exact amount of energy which reaches the microturbine, the energy conservation equation considering the loss of energy from friction was used. The results show different locations where it is possible to carry out the installation of a Francis turbine, which can generate an annual energy of approximately 280 MWh per year at the selected point, with an approximate investment cost of €20,000 per year, which means a recovery period of this investment of 2 years.

scholarly journals Designing of water distribution system

2021 ◽  
Vol 11 (3) ◽  
pp. 55-63
Author(s):  
Osama Khasraw Mohammed Amin ◽  
Mohammad Zaher Akkad ◽  
Tamás Bányai
Keyword(s):  
Distribution System ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution System ◽  
Treatment Plant ◽  
Working Hours ◽  
System Size ◽  
Efficient Design ◽  
Optimization Schemes

Water distribution system (WDS) aims to distribute water from reservoirs or aqueducts to the end-users. This system is part of the water supply network that carries potable water from a central treatment plant or wells to water consumers in order to deliver water sufficiently to meet residential, commercial, industrial, and firefighting requirements. Modern systems aim to solve water distribution systems management problems, such as the lowest cost, and most efficient design by using linear/nonlinear optimization schemes, which are limited by the system size, the number of constraints, and the number of loading conditions. After a literature review for the articles that dealt with this topic, designing two parts of the water distribution system is discussed as a case study in Erbil. Pumps and storage tanks, while optimizing the water distribution system by minimizing the project cost through minimizing the volume of the elevated tank according to the pump working hours.

Biofilm formation potentials in drinking waters treated by different advanced treatment processes

2002 ◽  
Vol 2 (4) ◽  
pp. 97-104 ◽  
Author(s):  
S. Okabe ◽  
T. Kokazi ◽  
Y. Watanabe
Keyword(s):  
Water Treatment ◽  
Distribution System ◽  
Biofilm Formation ◽  
Distribution Systems ◽  
Water Distribution ◽  
Treatment Plant ◽  
Biological Activated Carbon ◽  
Treatment Processes ◽  
Biological Treatments ◽  
The Impact

When biodegradable organic matter and other nutrients, such as ammonia and phosphorus, are not sufficiently removed during water treatment, bacteria may proliferate in the water distribution system. Bacterial regrowth deteriorates water quality (taste and odor), accelerates corrosion, and potentially increases the risk of microbial diseases. Therefore, this research was conducted to evaluate the impact of four different advanced water treatment processes, including biological treatments such as a rotating biofilm membrane reactor (RBMR) and a biological activated carbon (BAC) filter and ultrafiltration (UF), on reduction of nutrient levels and biofilm formation potentials of the treated water entering model distribution systems (annular reactors). Our results revealed that biological treatments significantly improved the “biostability” of water leaving from the treatment plant. On average, The RBMR and BAC filter reduced easily assimilable organic carbon (AOC) concentration by half when compared with conventional treatment (multi-media filtration; MF) and ultrafiltration (from 35-49 to 18-23 mg C L-1). Consequently, biofilm formation potential was reduced by a factor of 5 to 10 (from 3,200-5,100 to 490-710 pg ATP cm-2). With respect to “biostability” of water, ultrafiltration was less effective in reducing AOC concentrations. In addition, the impact of chlorine disinfection on biofilm accumulation and AOC levels in the distribution system were studied.

scholarly journals Analysis of chemical stability of tap water in terms of required level of technological safety

2017 ◽  
Vol 43 (4) ◽  
pp. 3-12 ◽  
Author(s):  
Katarzyna Pietrucha-Urbanik ◽  
Barbara Tchórzewska-Cieślak ◽  
Dorota Papciak ◽  
Izabela Skrzypczak
Keyword(s):  
Water Treatment ◽  
Water Supply ◽  
Chemical Stability ◽  
Distribution System ◽  
Distribution Systems ◽  
Water Distribution ◽  
Tap Water ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Corrosion Properties

AbstractThe main goal of this work is to show the new approach to determining safety technological levels (SLs) in terms of water quality and its chemical stability, as well as issues of water corrosion properties in water distribution systems (WDSs), due to the fact that water supply pipes are prone to corrosion. In the paper the methodology of determining the risk associated with threat to technical infrastructure was considered. The concept was studied on the basis of real operational data from the water treatment plant. The probability of exceeding the individual parameters for WTPI is slightly larger than for WTPII, which means that this water treatment process may cause lack of chemical stability in the water supply network. Operators should anticipate in the process of designing water distribution system, using proper materials, as to ensure an adequate level of safety from the water source to the water recipient. It should be noted that it is necessary to adjust the material of internal installation of water supply networks to the parameters of the water. At present, there are no correlations between the designing step and water parameters. It was concluded that to protect the water supply infrastructure, which belongs to critical infrastructure, water company should put more emphasis on distribution of stable water that has not potentially corrosion properties. Some suggestions were made for the protection of WDS and to ensure safety of system functioning and long-term usability of water pipes.

Potential for Energy Savings Through Residential Hot Water Distribution System Improvements

2009 ◽  
Author(s):  
Robert Hendron ◽  
Jay Burch ◽  
Marc Hoeschele ◽  
Leo Rainer
Keyword(s):  
Distribution System ◽  
Distribution Systems ◽  
Water Distribution ◽  
Energy Savings ◽  
Water Distribution Systems ◽  
Hot Water ◽  
Residential Energy ◽  
Simulation Tools ◽  
Residential Energy Efficiency ◽  
System Designs

Hot water distribution systems have received a great deal of attention recently, as residential energy efficiency programs target measures that can drive whole-house energy savings beyond the 50% level. Unfortunately, evaluating distribution losses and the resulting thermal interactions with space conditioning loads is very complicated, and must be performed using advanced simulation tools and realistic hot water event schedules, including appropriate event volumes, draw sequencing, and time between draw events. The authors developed a simplified methodology for the analysis of distribution losses based on detailed modeling of alternative system designs using HWSIM, a model specifically designed for this application. Curve fits were then applied to the results so they could be extrapolated to many different house designs and climate regions. The authors also performed preliminary analysis of whole house energy effects of alternate hot water distribution systems in two climates.

Sign in / Sign up

Export Citation Format

Share Document