Risk Assessment in Drinking Water Production Using Belief Functions

Free-living amoebae have been detected in a large number of man-made water systems, including drinking water distribution systems. Some of these amoebae can host amoebae-resisting bacteria, and thus act potentially as reservoirs and vehicles for a number of pathogens. The objectives of this study were to characterize the amoebae and amoebae-resisting bacteria present in different raw waters used for drinking water production, and to assess the efficiency of different treatments applied for drinking water production in removing or inactivating these amoebae. The preliminary results of this study confirm the presence of amoebae and amoebae-resisting bacteria in raw waters used for drinking water production. Due to their capacity to encyst, most of these amoebae are extremely resistant to disinfection processes. In these conditions, preventing the dissemination of these micro-organisms through drinking water will mainly require their physical removal by clarification and filtration processes. The particular hazard that amoebae-resisting bacteria represent in drinking water production should be taken into account in any risk assessment conducted in the framework of a water safety plan, and control strategies based on physical removal rather than disinfection should be adopted where necessary.

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Multi-Toxin Occurrences in Ten French Water Resource Reservoirs

Toxins ◽

10.3390/toxins10070283 ◽

2018 ◽

Vol 10 (7) ◽

pp. 283 ◽

Cited By ~ 14

Author(s):

Frederic Pitois ◽

Jutta Fastner ◽

Christelle Pagotto ◽

Magali Dechesne

Keyword(s):

Risk Assessment ◽

Drinking Water ◽

Species Composition ◽

Distribution Patterns ◽

Water Production ◽

Temperature Peak ◽

The Past ◽

Drinking Water Production ◽

Toxin Class ◽

Psp Toxins

Cyanobacteria are known to produce a wide array of metabolites, including various classes of toxins. Among these, hepatotoxins (Microcystins), neurotoxins (Anatoxin-A and PSP toxins) or cytotoxins (Cylindrospermopsins) have been subjected to numerous, individual studies during the past twenty years. Reports of toxins co-occurrences, however, remain scarce in the literature. The present work is an inventory of cyanobacteria with a particular focus on Nostocales and their associated toxin classes from 2007 to 2010 in ten lakes used for drinking water production in France. The results show that potential multiple toxin producing species are commonly encountered in cyanobacteria populations. Individual toxin classes were detected in 75% of all samples. Toxin co-occurrences appeared in 40% of samples as two- or three-toxin combinations (with 35% for the microcystins–anatoxin combination), whereas four-toxin class combinations only appeared in 1% of samples. Toxin co-occurrences could be partially correlated to species composition and water temperature. Peak concentrations however could never be observed simultaneously and followed distinct, asymmetrical distribution patterns. As observations are the key for preventive management and risk assessment, these results indicate that water monitoring should search for all four toxin classes simultaneously instead of focusing on the most frequent toxins, i.e., microcystins.

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Coagulation/flocculation/ultrafiltration for natural organic matter removal in drinking water production

Water Science & Technology Water Supply ◽

10.2166/ws.2004.0111 ◽

2004 ◽

Vol 4 (5-6) ◽

pp. 215-222 ◽

Cited By ~ 2

Author(s):

A.R. Costa ◽

M.N. de Pinho

Keyword(s):

Drinking Water ◽

Organic Matter ◽

Natural Organic Matter ◽

Membrane Fouling ◽

Membrane Filtration ◽

Membrane Surface ◽

Water Production ◽

Cellulose Acetate Membranes ◽

Wide Range ◽

Drinking Water Production

Membrane fouling by natural organic matter (NOM), namely by humic substances (HS), is a major problem in water treatment for drinking water production using membrane processes. Membrane fouling is dependent on membrane morphology like pore size and on water characteristics namely NOM nature. This work addresses the evaluation of the efficiency of ultrafiltration (UF) and Coagulation/Flocculation/UF performance in terms of permeation fluxes and HS removal, of the water from Tagus River (Valada). The operation of coagulation with chitosan was evaluated as a pretreatment for minimization of membrane fouling. UF experiments were carried out in flat cells of 13.2×10−4 m2 of membrane surface area and at transmembrane pressures from 1 to 4 bar. Five cellulose acetate membranes were laboratory made to cover a wide range of molecular weight cut-off (MWCO): 2,300, 11,000, 28,000, 60,000 and 75,000 Da. Severe fouling is observed for the membranes with the highest cut-off. In the permeation experiments of raw water, coagulation prior to membrane filtration led to a significant improvement of the permeation performance of the membranes with the highest MWCO due to the particles and colloidal matter removal.

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Barcelona's water supply improvement: the brine collector of the Llobregat river

Water Science & Technology ◽

10.2166/wst.1994.0531 ◽

1994 ◽

Vol 30 (10) ◽

pp. 221-227 ◽

Cited By ~ 8

Author(s):

Jordi Martín-Alonso

Keyword(s):

Drinking Water ◽

Surface Water ◽

Treatment Plant ◽

Water Treatment Plant ◽

Salt Mine ◽

Water Production ◽

Public Work ◽

Drinking Water Production ◽

Llobregat River

The Llobregat is a 156 km long river, which supplies 35% of the Barcelona's drinking water needs from the Sant Joan Despí Water Treatment Plant. Since the establishment of the Salt Mine Works in the Llobregat basin in 1923, a progressive salinization of the water sources has been recorded. The operation of the Brine Collector, as a public work carried out by Aigües de Barcelona (AGBAR), started in 1989; it enabled a very significant improvement in the quality of the surface water used for drinking-water production.

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System Analysis of Source Water Indicators at Drinking Water Production in the Central Water Supply System

Intellekt Sist Proizv ◽

10.22213/2410-9304-2018-2-84-96 ◽

2018 ◽

Vol 16 (2) ◽

pp. 84

Author(s):

G A Blagodatsky ◽

A A Bass ◽

M M Gorokhov ◽

D S Ponomarev

Keyword(s):

Drinking Water ◽

Water Supply ◽

System Analysis ◽

Supply System ◽

Water Supply System ◽

Source Water ◽

Water Production ◽

Drinking Water Production

Работа посвящена системному анализу данных показателей исходной воды при производстве питьевой воды в системе центрального водоснабжения крупного населенного пункта. На сегодняшний день на фоне увеличивающегося негативного антропогенного воздействия на окружающую среду наблюдается ухудшение состояния многих источников питьевого водоснабжения в широком спектре показателей, в частности, таких как органолептические свойства воды. Как следствие, возникает проблема и для питьевой воды. В работе приводится процесс подготовки данных о параметрах исходной воды, забираемой из водохранилища, которые ежемесячно (с 2002 по 2014 год) учитывались на предприятии при дезодорации воды. Приведенные параметры оказывают существенное влияние на органолептические свойства конечной воды. Подготовка данных для анализа проводится методом главных компонент К. Пирсона. Данные, полученные в пространстве R9, переводятся в пространство меньшей размерности R3. Понижение размерности позволяет снизить автокорреляцию между компонентами. Отбор компонент в пространство R3 проводится по правилу Парето. В пространстве R3 методом сферической кластеризации данных «Форель» с постоянным радиусом группировки проводится кластеризация. Приводится пошаговое визуальное представление алгоритма кластеризации в пространстве R3. В работе показано, что в данных показателях качества исходной воды имеются кластеры. Проводится корреляционно-регрессионный анализ данных, представленных в главных компонентах. Строятся регрессионные зависимости показателей органолептических свойств от главных компонент из пространства R3.

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