Análise de sensibilidade às componentes do balanço hídrico para suporte a uma melhor gestão de perdas em sistemas de abastecimento de água

2020 ◽  
pp. 27
Author(s):  
Dália Loureiro ◽  
◽  
Aisha Mamade ◽  
Maria Almeida Silva ◽  
Francisco Arregui ◽  
...  
Keyword(s):  
Drinking Water ◽  
Water Balance ◽  
Water Loss ◽  
Distribution Systems ◽  
Water Distribution ◽  
Performance Indicator ◽  
Water Supply Systems ◽  
Water Balance Components ◽  
Non Revenue Water

Apesar da qualidade de serviço assegurada atualmente pelos sistemas de abastecimento de água (SAA) em Portugal, o valor de água não faturada nos sistemas em “baixa” tem-se mantido praticamente constante e com desempenho insatisfatório nos últimos anos. O balanço hídrico constitui um standard para avaliar a água entrada, o consumo faturado e não faturado em SAA. A quantificação fiável das componentes de água não faturada, para identificação dos principais problemas de perdas, constitui uma etapa preliminar crucial para a definição de um plano de gestão de perdas de água e de energia a médio prazo. No entanto, devido ao facto de várias componentes do balanço serem obtidas por estimativa, são necessárias abordagens que permitam o seu cálculo sistemático e uma avaliação da qualidade dos resultados com vista à redução das incertezas e a uma melhor avaliação da dimensão do problema. Este artigo analisa a incerteza das componentes do balanço hídrico, identifica alguns fatores que podem influenciar a qualidade da medição da água entrada e faz uma análise de sensibilidade ao indicador de perdas aparentes num conjunto de 22 entidades gestoras de sistemas de distribuição de água. Despite the high quality of service provided nowadays by drinking water supply systems in Portugal, the value of non-revenue water in drinking water distribution systems (DWDS) has been practically constant and with a poor service level in last years. The water balance is a standard for assessing system input volume, billed consumption and non-revenue water components in DWDS. Reliable quantification of non-revenue water components, for identification of the main problems, is an essential preliminary step in the definition of a plan for water loss and energy management in a medium-term horizon. However, because several components of the water balance are obtained by estimation, approaches are necessary to enable them to be systematically calculated and to evaluate the quality of results to reduce uncertainties and to better assess the water loss problems. This paper analyses the uncertainty associated with water balance components and the results of the apparent loss performance indicator in a set of 22 DWDS to establish reference values.

scholarly journals Trihalomethanes formation in Iranian water supply systems: predicting and modeling

2015 ◽  
Vol 13 (3) ◽  
pp. 859-869 ◽  
Author(s):  
Ali Akbar Babaei ◽  
Leila Atari ◽  
Mehdi Ahmadi ◽  
Kambiz Ahmadiangali ◽  
Mirzaman Zamanzadeh ◽  
...  
Keyword(s):  
Drinking Water ◽  
Water Temperature ◽  
Distribution Systems ◽  
Water Distribution ◽  
Pearson Correlation ◽  
Multiple Linear Regression Model ◽  
Residual Chlorine ◽  
Water Supply Systems ◽  
Drinking Water Distribution Systems ◽  
Bromide Ion

Trihalomethanes (THMs) were the first disinfection by-products discovered in drinking water and are classified as probable carcinogens. This study measures and models THMs formation at two drinking water distribution systems (WDS1 and WDS2) in Ahvaz City, Iran. The investigation was based on field-scale investigations and an intensive 36-week sampling program, from January to September 2011. The results showed total THM concentrations in the range 17.4–174.8 μg/L and 18.9–99.5 μg/L in WDS1 and WDS2, respectively. Except in a few cases, the THM concentrations in WDS1 and WDS2 were lower than the maximum contaminant level values. Using two-tailed Pearson correlation test, the water temperature, dissolved organic carbon, UV254, bromide ion (Br−), free residual chlorine, and chlorine dose were identified as the significant parameters for THMs formation in WDS2. Water temperature was the only significant parameter for THMs formation in WDS1. Based on the correlation results, a predictive model for THMs formation was developed using a multiple regression approach. A multiple linear regression model showed the best fit according to the coefficients of determination (R2) obtained for WDS1 (R2 = 0.47) and WDS2 (R2 = 0.54). Further correlation studies and analysis focusing on THMs formation are necessary to assess THMs concentration using the predictive models.

scholarly journals Socio-economic aspects of epidemiology of helicobateriosis

2019 ◽  
Vol 95 (9) ◽  
pp. 861-864
Author(s):  
Tatiana P. Fedichkina ◽  
L. G. Solenova ◽  
I. E. Zykova ◽  
S. V. German ◽  
A. V. Modestova ◽  
...  
Keyword(s):  
Public Health ◽  
Helicobacter Pylori ◽  
Drinking Water ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution Systems ◽  
Helicobacter Pylori Infection ◽  
Technical State ◽  
Economic Aspects

There are considered special social and economic aspects of the epidemiology of Helicobacter pylori. These aspects acquired the particular importance for the last time due to the fact that the provision of the people with pure water has been becoming the focus of the attention of geopolitical and socio-economic interests in a number of countries. The availability ofpure drinking water serves a marker of the socio-economic state of the territory and the population living there. In Russia where different climatic conditions are deposited by considerable regional differences in the conditions of communal services caused both by various level of the socio-economic development of the territory, the supplementation with pure drinking water serves as the social determinant of the ecological conditions of the population’s life. This particularly has impact on the unfeasible technical state of the water distribution systems, microorganism ecology of which can substantially affect public health. The performed by authors a specialized screening ofpresented at the official web site of the joint-stock company «Mosvodokanal» current data concerning the quality of drinking water consumed by 2500 Moscovites, tested for the Helicobacter pylori infection revealed no deviations from the sanitary standards in the water received by the consumers. Along with that, the comparison of the map documents of the distribution of the Helicobacter pylori infection in Moscow with the distribution of citizens’ complaints of the decline of the quality of tap water has revealed a territorial fastening of the high values of the population infection rate of n^ylori and the urban sites with the greatest number of complaints. In the microbial ecology of water-distribution systems there are tightly aligned problems of their epidemiological safety, technical state and economic damage caused by corrosion as a result of microbiotic activity. In contrast to acute bacterial and viral infections which are deemed of the greatest importance when assessing the sanitary condition of water sources and water-distribution systems, the consequences of infection with H. pylori may not be manifestedfor a long time but some years later they may be manifested as serious chronic diseases (from gastritis to adenocarcinoma of the stomach and a wide range of extraintestinal pathologies), which causes great social and economic losses. Thus, the socio-economic aspect of the epidemiology of helicobacteriosis includes at least two components: the technic - the maintenance of the feasible technic and sanitary state of the water distribution systems and the medico-social - expenditures for screening and treatment of infected patients. In total they are an inseparable part of the prevention of socially-important diseases in the public health system.

scholarly journals Average Operating Pressure Effect on Water Supply Systems Performances. A Case Study for 12 Romanian Small Water Distribution Networks

2021 ◽  
Vol 11 (2) ◽  
pp. 143-150
Author(s):  
E. Vitan ◽  
Anca Hotupan ◽  
Adriana Hadarean
Keyword(s):  
Performance Evaluation ◽  
Water Loss ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution Systems ◽  
Distribution Networks ◽  
Water Supply Systems ◽  
Operating Pressure ◽  
Water Network ◽  
Small Water

Abstract The performance evaluation of an implemented water distribution network is in tight relation with the choice of adequate measures for water loss reduction. Hence, the consequences of placing the water network in a wrong performance category are bad and will conduct to unreasonably costs or considerable water loss volumes. Therefore, the evaluation of the water network performance level based on both Non-Revenue Water (NRW) and Infrastructure Leakage Index (ILI) indicators is to be recommended. This paper deals with the performance evaluation of water distribution systems based on the calculated performance indicators NRW and ILI. For this purpose, collected data for a period of one year from 12 Romanian small water distribution systems and two simplified average pressure determination methods were used.

scholarly journals Dynamics of Biofilm Regrowth in Drinking Water Distribution Systems

2016 ◽  
Vol 82 (14) ◽  
pp. 4155-4168 ◽  
Author(s):  
I. Douterelo ◽  
S. Husband ◽  
V. Loza ◽  
J. Boxall
Keyword(s):  
Drinking Water ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution Systems ◽  
Influential Factors ◽  
Residual Chlorine ◽  
Water Supply Systems ◽  
Drinking Water Distribution Systems ◽  
Drinking Water Distribution ◽  
Biofilm Development

ABSTRACTThe majority of biomass within water distribution systems is in the form of attached biofilm. This is known to be central to drinking water quality degradation following treatment, yet little understanding of the dynamics of these highly heterogeneous communities exists. This paper presents original information on such dynamics, with findings demonstrating patterns of material accumulation, seasonality, and influential factors. Rigorous flushing operations repeated over a 1-year period on an operational chlorinated system in the United Kingdom are presented here. Intensive monitoring and sampling were undertaken, including time-series turbidity and detailed microbial analysis using 16S rRNA Illumina MiSeq sequencing. The results show that bacterial dynamics were influenced by differences in the supplied water and by the material remaining attached to the pipe wall following flushing. Turbidity, metals, and phosphate were the main factors correlated with the distribution of bacteria in the samples. Coupled with the lack of inhibition of biofilm development due to residual chlorine, this suggests that limiting inorganic nutrients, rather than organic carbon, might be a viable component in treatment strategies to manage biofilms. The research also showed that repeat flushing exerted beneficial selective pressure, giving another reason for flushing being a viable advantageous biofilm management option. This work advances our understanding of microbiological processes in drinking water distribution systems and helps inform strategies to optimize asset performance.IMPORTANCEThis research provides novel information regarding the dynamics of biofilm formation in real drinking water distribution systems made of different materials. This new knowledge on microbiological process in water supply systems can be used to optimize the performance of the distribution network and to guarantee safe and good-quality drinking water to consumers.

scholarly journals Optimal Time Step Length to Minimize Uncertainty of Zonal Water Balance Calculation in Drinking Water Distribution Systems

10.29007/5r9x ◽  
2018 ◽  
Author(s):  
Attila Bibok ◽  
Roland Fülöp
Keyword(s):  
Drinking Water ◽  
Water Balance ◽  
Distribution System ◽  
Distribution Systems ◽  
Water Distribution ◽  
Training Dataset ◽  
Optimal Time ◽  
Time Step ◽  
Balance Calculation ◽  
Drinking Water Distribution

Water balance calculation is a well-known and adapted method to analyze district-metered areas (DMAs) of drinking water distribution system. Other application of water balance results can be training dataset for consumption forecast, monitoring and managing water loss. The vast amount of application makes it a very powerful tool, which is in contrary sensitive to the accuracy of the calculation. The uncertainty of flow metering decreases as the length of the time step decreases, however, the uncertainty of stored volume measurement in tanks increases. Investigation of the limitations of water balance calculation in regard to uncertainty is necessary to develop an analytical solution for optimal calculation time step.

scholarly journals Non-invasive Biofouling Monitoring to Assess Drinking Water Distribution System Performance

2021 ◽  
Vol 12 ◽  
Author(s):  
Frances C. Pick ◽  
Katherine E. Fish ◽  
Stewart Husband ◽  
Joby B. Boxall
Keyword(s):  
Drinking Water ◽  
Distribution System ◽  
Distribution Systems ◽  
Water Distribution ◽  
Bulk Water ◽  
Water Supply Systems ◽  
Customer Contact ◽  
Drinking Water Distribution Systems ◽  
Drinking Water Distribution ◽  
Contact Data

Biofilms are endemic in drinking water distribution systems (DWDS), forming on all water and infrastructure interfaces. They can pose risks to water quality and hence consumers. Our understanding of these biofilms is limited, in a large part due to difficulties in sampling them without unacceptable disruption. A novel, non-destructive and non-disruptive biofilm monitoring device (BMD), which includes use of flow cytometry analysis, was developed to assess biofouling rates. Laboratory based experiments established optimal configurations and verified reliable cell enumeration. Deployment at three operational field sites validated assessment of different biofouling rates. These differences in fouling rates were not obvious from bulk water sampling and analysis, but did have a strong correlation with long-term performance data of the associated networks. The device offers the potential to assess DWDS performance in a few months, compared to the number of years required to infer findings from historical customer contact data. Such information is vital to improve the management of our vast, complex and uncertain drinking water supply systems; for example rapidly quantifying the benefits of improvements in water treatment works or changes to maintenance of the network.

Kinetics and mechanism of abiotic decomposition of malodorous dimethyl disulfide under dark, oxic conditions

2019 ◽  
Vol 16 (3) ◽  
pp. 165 ◽  
Author(s):  
Tamir Buchshtav ◽  
Alon Amrani ◽  
Alexey Kamyshny Jr
Keyword(s):  
Drinking Water ◽  
Aqueous Solutions ◽  
Half Life ◽  
Distribution Systems ◽  
Water Distribution ◽  
Tap Water ◽  
Dimethyl Disulfide ◽  
Hydroxyl Ion ◽  
Abiotic Decomposition

Environmental contextDimethyl disulfide, a malodorous product of decomposing organic matter, can severely compromise the quality of drinking water. We studied the abiotic decomposition of dimethyl disulfide in aqueous solutions under dark, oxygenated conditions and found that the half-life varied from thousands to hundreds of thousands of years. The results indicate that in natural aquatic systems the decomposition of dimethyl disulfide is governed by other chemical, photochemical and microbial processes. AbstractThe presence of malodorous dimethyl polysulfides (DMPSs) has been documented in limnic systems as well as in tap water distribution systems. These compounds compromise the quality of drinking water. In this work, we studied kinetics and mechanisms of the decomposition reactions of the most abundant and stable DMPS, dimethyl disulfide (DMDS), in aqueous solutions in the presence of oxygen and absence of light. It was found that DMDS reacts with a hydroxyl ion and its decomposition leads to the formation of methyl mercaptan and other products. The decomposition reaction is of the first order with respect to both the concentration of DMDS and the activity of the hydroxyl ion, with an activation energy of 90±8kJmol−1. The half-life of DMDS under abiotic, dark, oxic conditions was observed to vary from thousands to hundreds of thousands of years depending on the pH and temperature. These results indicate that DMDS is decomposed by other chemical, photochemical and microbially-mediated pathways.

Assessment of microbial support potential of six materials used in drinking water distribution systems

2006 ◽  
Vol 37 (2) ◽  
pp. 175-188 ◽  
Author(s):  
F. Enkiri ◽  
J-Y. Legrand ◽  
F. Squinazi ◽  
J-C. Ponelle ◽  
P. Leroy
Keyword(s):  
Drinking Water ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution Systems ◽  
Drinking Water Distribution Systems ◽  
Drinking Water Distribution ◽  
Materials Used
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