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Le Touquet – Paris-Plage, France

Marconnet C.,Veolia | Feliers C.,Veolia | Lang A.,Syndicat des Eaux dIle de France
AWWA/AMTA Membrane Technology Conference and Exposition 2012

Nanofiltration (NF) membrane technology has become a secure and efficient way to produce safe drinking water complying with local legislations all around the world. This process can supply higher quality drinking water to meet the ever increasing customer expectations. Indeed membranes act as barriers for most of the contaminants found in raw water: micro-organisms (bacteria, parasites, fungi and algae), virus, organic matter, sulphates, nitrates, toxic heavy metals, micropollutants (pesticides, endocrine disruptors, pharmaceuticals, etc.). Membranes are thus able to improve the water quality at the outlet of the plant, in particular its taste, its odour and its stability in the distribution system. Moreover membranes are likely to reject future micropollutants, molecules which are still analytically-undetectable today but may be synthesized and discharged in the environment in the forthcoming years. The main limitation of membrane filtration is fouling. Membrane fouling generates flux decline, leading to higher energy consumptions and higher chemical cleaning frequencies, therefore to an increase of the drinking water production cost. Besides, fouling induces a reduction of membrane lifetime. Fouling can be controlled by both preventive (adjusted pre-treatment) and corrective (cleaning in place) actions. This work focuses on NF pre-treatment and its influence on the membrane fouling kinetics. The goal of this study is to compare conventional and membrane pre-treatments prior to nanofiltration, and to determine their relative interest to control fouling. NF is studied here at a pilot scale in Choisy-le-Roi drinking water treatment plant (WTP), located in the suburbs of Paris in France and operated by Veolia Water on behalf of the Syndicat des Eaux d'Ile-de-France (SEDIF). This WTP treats river water according to a conventional process composed of pre-ozonation, coagulation/flocculation/sedimentation, sand filtration, ozonation, GAC adsorption and chlorination. Two three-stage NF membrane prototypes (250 m3/day) are fed different water qualities. The reference prototype is fed GAC-filtered water coming from the WTP. Before entering the NF 1st stage, GAC-filtered water is acidified (pH 6.9), pre-filtered (6 μm cut-off cartridge) and dosed with an antiscalant. The test prototype is fed by a microfiltration pilot plant treating 0.4 NTU settled water coming from the WTP and previously acidified at pH 6.9. Microfiltration membranes used in this work are hollow-fibre modules, in an outside-inside submerged configuration. All membranes are operated in a constant flux mode. Membrane performances (water permeability, rejections) are continuously monitored. Water quality is also carefully determined during the whole test. In the end assets and drawbacks of membrane pre-treatment compared to conventional pre-treatment are discussed, both in terms of water quality and in terms of membrane fouling kinetics. © 2012 American Water Works Association. Source

Botta F.,University Pierre and Marie Curie | Fauchon N.,Veolia | Blanchoud H.,University Pierre and Marie Curie | Chevreuil M.,University Pierre and Marie Curie | Guery B.,Syndicat des Eaux dIle de France

This paper presents first results of Phyt'Eaux Cités, a program put in place by the local water supply agency, the SEDIF (Syndicat des Eaux d'Ile-de-France), in collaboration with 73 local authorities, private societies and institutional offices (365km 2). The challenges included: measurement of the previous surface water contamination, control of urban pesticide applications, prevention of pesticide hazard on users and finally a overall reduction of surface water contamination. An inquiry on urban total pesticide amount was coupled with a surface water bi-weekly monitoring to establish the impact of more than 200 molecules upon the Orge River. For 2007, at least 4400kg and 92 type of pesticides (essentially herbicides) were quantified for all urban users in the Phyt'Eaux Cités perimeter. At the outlet of the Orge River (bi-weekly sampling in 2007), 11 molecules were always detected above 0.1μgL -1. They displayed the mainly urban origin of pesticide surface water contamination. Amitrole, AMPA (Aminomethyl Phosphonic Acid), demethyldiuron, diuron, glyphosate and atrazine were quantified with a 100% of frequency in 2007 and 2008 at the Orge River outlet. During the year, peaks of contamination were also registered for MCCP, 2,4 MCPA, 2,4 D, triclopyr, dichlorprop, diflufènican, active substances used in large amount in the urban area. However, some other urban molecules, such as isoxaben or flazasulfuron, were detected with low frequency. During late spring and summer, contamination patterns and load were dominated by glyphosate, amitrole and diuron, essentially applied by cities and urban users. Both isoproturon and chlortoluron were quantified during autumn and winter months according to upstream agricultural practices. In conclusion, 3years after the beginning of this programme, the cities reduced the use of 68% of the total pesticide amount. An improvement on surface water quality was found from 2008 and during 2009 for all pesticides. In particular, glyphosate showed a decrease of the load above 60% in 2008, partly related to the Phyt'Eaux Cités action. © 2011 Elsevier Ltd. Source

Marconnet C.,Veolia Water | Houari A.,Cergy-Pontoise University | Seyer D.,Cergy-Pontoise University | Djafer M.,Veolia Water | And 3 more authors.

The effect of ultraviolet (UV) irradiation on nanofiltration (NF) membrane biofouling has been studied in pilot scale installations using two identical parallel membrane pilots and a low pressure UV reactor. The two pilots were fed either granular activated carbon (GAC)-filtered water or UV-irradiated GAC-filtered water during a filtration run of 20. weeks. UV pre-treatment did not affect the organic carbon concentration but decreased the active planktonic bacteria counts and increased the dead planktonic bacteria counts of the feed water. Membrane permeability and longitudinal pressure drop (LPD) were continuously monitored during the experiments. UV irradiation was associated with much lower LPD increase, and moderate permeate flux decline. At the end of the test, spiral-wound modules were autopsied and analysed. Membranes of UV-irradiated pilot harboured decreased amounts of biofoulants (global quantity of deposit, sessile bacteria and ATP concentration and amount of extracellular polymeric substances). In conclusion, both membrane performances monitoring and foulant analysis showed that UV irradiation was an efficient NF pre-treatment to reduce NF membrane biofouling. © 2011 Elsevier B.V. Source

Drinking water disinfection eliminates pathogenic microorganisms and maintains the microbiological quality of water until it reaches the consumer's tap, but may lead to the formation of by-products (DBPs). To date, studies have identified more than 600 DBPs. In France, trihalomethanes (THMs) and bromate, which are regulated and regularly analysed, are the main SPDs usually encountered in water produced and distributed. These parameters are generated during the disinfection step by chemical reactions between precursors naturally present in the water and the oxidants used. This document is intended to operators. It aims to help them identify key treatment steps and actions to be taken in order to reduce the formation of these SPDs and limit their concentrations in the water distributed. It also aims at limiting other disinfection by-products potentially formed, which are not regulated today. Source

Chagneau G.,Syndicat des Eaux dIle de France | Colon A.-L.,Syndicat des Eaux dIle de France | Lefort C.,Syndicat des Eaux dIle de France
Techniques - Sciences - Methodes

The Choisy-le-Roi drinking water plant produces an average 340,000 m 3 per day and has a peak capacity of 600,000 m3 per day. Before water is injected in the distribution network, it is disinfected using chlorine solution. To this effect, the initial installation included a storage tank supplemented in 1995 by electrochlorination process with a production capacity of 37 kg per hour. In 2012, the equipment was to be replaced by a set of three electro-chlorination lines and a 400 t tank to store a hypochlorite solution of 6 g/L. However, in accordance with Seveso 2 directives 11996) this led to classifying the installation as "Sevesco high-threshold" because the European CLP regulation (Classification, Labelling and Packaging) classifies chlorine under ICPE headings 1171 and 1172 regardless of its concentration. This paper describes how the chlorination unit was finally redesigned to reduce storage capacity under 200 tons enabling its classification as "Seveso lowthreshold". Source

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