scholarly journals Trihalomethanes in Water Supply System and Water Distribution Networks

Author(s):  
Sornsiri Sriboonnak ◽  
Phacharapol Induvesa ◽  
Suraphong Wattanachira ◽  
Pharkphum Rakruam ◽  
Adisak Siyasukh ◽  
...  

The formation of trihalomethanes (THMs) in natural and treated water from water supply systems is an urgent research area due to the carcinogenic risk they pose. Seasonal effects and pH have captured interest as potential factors affecting THM formation in the water supply and distribution systems. We investigated THM occurrence in the water supply chain, including raw and treated water from water treatment plants (coagulation, sedimentation, sand filtration, ClO2-disinfection processes, and distribution pipelines) in the Chiang Mai municipality, particularly the educational institute area. The effects of two seasons, rainy (September–November 2019) and dry (December 2019–February 2020), acted as surrogates for the water quality profile and THM occurrence. The results showed that humic acid was the main aromatic and organic compound in all the water samples. In the raw water sample, we found a correlation between surrogate organic compounds, including SUVA and dissolved organic carbon (DOC) (R2 = 0.9878). Four species of THMs were detected, including chloroform, bromodichloromethane, dibromochloromethane, and bromoform. Chloroform was the dominant species among the THMs. The highest concentration of total THMs was 189.52 μg/L. The concentration of THMs tended to increase after chlorination when chlorine dioxide and organic compounds reacted in water. The effect of pH on the formation of TTHMs was also indicated during the study. TTHM concentrations trended lower with a pH ≤ 7 than with a pH ≥ 8 during the sampling periods. Finally, in terms of health concerns, the concentration of TTHMs was considered safe for consumption because it was below the standard (<1.0) of WHO’s Guideline Values (GVs).

2020 ◽  
Vol 10 (22) ◽  
pp. 8219
Author(s):  
Andrea Menapace ◽  
Ariele Zanfei ◽  
Manuel Felicetti ◽  
Diego Avesani ◽  
Maurizio Righetti ◽  
...  

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.


1988 ◽  
Vol 78 (2) ◽  
pp. 317-328 ◽  
Author(s):  
P. H. Langton ◽  
P. S. Cranston ◽  
P. Armitage

AbstractChironomid midges have been known to include parthenogenetic species for over a century. One of these species, Paratanytarsus grimmii (Schneider), cited under several different names here shown to be junior synonyms, has attained some notoriety as a pest. Its occurrence as a supposedly paedogenetic (actually pharate adult parthenogenetic) inhabitant of water distribution systems is discussed and related to its more usual occurrence in a variety of small water bodies including aquaria. New synonymy is proposed and a lectotype designated.


2010 ◽  
Vol 3 (1) ◽  
pp. 21-27 ◽  
Author(s):  
J. Machell ◽  
S. R. Mounce ◽  
J. B. Boxall

Abstract. Hydraulic simulation models of water distribution networks are routinely used for operational investigations and network design purposes. However, their full potential is often never realised because, in the majority of cases, they have been calibrated with data collected manually from the field during a single historic time period and, as such, reflect the network operational conditions that were prevalent at that time, and they are then applied as part of a reactive, desktop investigation. In order to use a hydraulic model to assist proactive distribution network management its element asset information must be up to date and it should be able to access current network information to drive simulations. Historically this advance has been restricted by the high cost of collecting and transferring the necessary field measurements. However, recent innovation and cost reductions associated with data transfer is resulting in collection of data from increasing numbers of sensors in water supply systems, and automatic transfer of the data to point of use. This means engineers potentially have access to a constant stream of current network data that enables a new era of "on-line" modelling that can be used to continually assess standards of service compliance for pressure and reduce the impact of network events, such as mains bursts, on customers. A case study is presented here that shows how an online modelling system can give timely warning of changes from normal network operation, providing capacity to minimise customer impact.


2021 ◽  
Vol 11 (2) ◽  
pp. 143-150
Author(s):  
E. Vitan ◽  
Anca Hotupan ◽  
Adriana Hadarean

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.


Proceedings ◽  
2018 ◽  
Vol 2 (23) ◽  
pp. 1440 ◽  
Author(s):  
Jorge García Morillo ◽  
Juan A. Rodríguez Díaz ◽  
Miguel Crespo ◽  
Aonghus McNabola

In Spain and other countries, open channel distribution networks have been replaced by on demand-pressurized networks to improve the water-use efficiency of the water distribution systems, but at the same time the energy requirements have dramatically risen. Under this scenario, methodologies to reduce the energy consumption are critical such as: irrigation network sectoring, critical hydrant detection, improving the efficiency of the pumping system and the irrigation system, or introducing solar energy for water supply. But once these measures are undertaken, the recovery of the energy inherent in excess pressure in the network should be investigated. Hydropower energy recovery in irrigation is still largely unexplored and requires further investigation and demonstration. All of these methodologies should be considered as useful tools for both, the reduction of energy consumption and the recovery of the excess energy in pressurized irrigation networks. To accomplish this, the REDAWN project (Reducing Energy Dependency in Atlantic Area Water Networks) aims to improve the energy efficiency of water networks through the installation of innovative micro-hydropower (MHP) technology. This technology will recover wasted energy in existing pipe networks across irrigation, public water supply, process industry, and waste-water network settings.


2015 ◽  
Vol 18 (1) ◽  
pp. 115-125 ◽  
Author(s):  
Fulvio Boano ◽  
Silvia Fiore ◽  
Roberto Revelli

Chlorine-based disinfection agents are known to favor the production of disinfection by-products (DBPs), whose concentrations are restricted by international guidelines to ensure a safe consumption of drinking water. Hence, it is important to understand the behavior of DBPs within water distribution networks (WDNs) to avoid users' exposure to concentrations higher than guideline values. The build-up in chlorate concentration resulting from chlorinated disinfectants is here simulated with the EPANET 2.0 software for one benchmark WDN serving about 130,000 inhabitants. Chlorate generation was accounted by means of an empirical model, considering different boundary conditions (physicochemical features of raw water, disinfectant dose). The gathered results indicate that increases in chlorate concentration within the considered WDN are narrow. Chlorate neo-formation in the WDN is, however, strictly related to the initial amount of chlorate released by the water treatment plant, i.e., to the input value in the WDN. If chlorate concentration in treatment plants is kept below 700 μg/L (i.e., World Health Organization guideline), depending on the mixing conditions in tanks, the simulation results referred to the considered WDN show that the DBP build-up within the network is limited (in any case lower than 5–7% of the threshold value).


2014 ◽  
Vol 909 ◽  
pp. 428-432 ◽  
Author(s):  
Ioan Sarbu ◽  
Gabriel Ostafe

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.


2015 ◽  
Vol 1 (2) ◽  
pp. 129-134
Author(s):  
Ladislav Tuhovčák ◽  
Miloslav Tauš ◽  
Tomáš Sucháček

The knowledge of the current technical condition of the operated system is in the interest of the owner or operator of public water supply systems. Such information is the starting point when making decisions on investment projects or planning water mains renewal. The submitted paper introduces the methodology of preliminary assessment of the technical condition of water supply systems and outputs of the software application TEA Water, which makes it possible to assess the technical condition of the specific elements of the water supply systems and clear displaying with the presentation of the assessment results for the entire considered water supply system.


Author(s):  
А.В. Степакин ◽  
А.Н. Перегуда ◽  
С.Г. Зайцева ◽  
Д.А. Горбачев ◽  
М.Н. Сопыряев

Природный дефицит водных ресурсов в сочетании с высокой степенью износа систем водоснабжения обусловливает напряженную ситуацию с обеспечением питьевой водой в Крыму. За последние несколько лет для решения проблемы на региональном и федеральном уровне были разработаны и реализуются программы модернизации водного хозяйства полуострова. Одной из ключевых задач этих программ является снижение потерь воды, которые в настоящее время достигают 40–60%. Описан комплекс мероприятий, направленных на снижение потерь воды в г. Севастополе. Комплекс мер, разработанный в соответствии с международным опытом и российскими рекомендациями, учитывает существующее состояние системы водоснабжения Крыма. Мероприятия включают в себя создание современного комплекса управления сетями, зонирование водопроводной сети, регулирование давления, мониторинг и устранение утечек. По результатам анализа производственных показателей определено, что первоочередным мероприятием для Севастополя является внедрение современной системы акустического мониторинга на распределительных сетях, которая позволит эффективно обнаруживать скрытые утечки и сэкономить городу тысячи кубометров дефицитной питьевой воды. Описаны результаты пилотного проекта по обследованию 5 км водопроводных сетей системой акустического мониторинга. The natural scarcity of water resources coupled with a high degree of deterioration of water supply systems result in a tense situation with the drinking water supply in Crimea. Over the past few years, a number of programs of upgrading the peninsula's water industry have been developed and are being implemented in order to solve the problem at the regional and federal levels. One of the key objectives of these programs is to reduce water losses that currently reach 40–60%. A set of measures aimed at reducing water losses in Sebastopol is described. The set of measures developed in accordance with the international experience and Russian recommendations takes into account the current condition of the Crimean water supply system. The activities include designing an advanced network management complex, zoning of the water supply network, pressure regulation, monitoring and elimination of leaks. Based on the results of the analysis of the performance indicators, it was determined that the priority measure for Sebastopol was the introduction of an advanced acoustic monitoring system in the water distribution networks that would provide for detecting effectively latent leaks and saving the city thousands of cubic meters of scarce drinking water. The results of a pilot project on the inspection of 5 km of the water supply networks using the acoustic monitoring system are described.


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