No. 4 / July-August 2005 / Research & Development The magazine of the Scientific Chronicles Seawater desalination
Did you know? Key information Of strategic importance The first desalination In the 1960’s, thermal processes 72% of the earth’s surface is processes: were developed and used to covered in water. “Desalination is of strategic In the 4th century BC, Aristotle desalinate seawater. Also, 97% of this water is saline importance to Veolia observed the principle of research was carried out on a Environnement. distillation. desalination process utilizing The average salinity of seawater is Seawater is an alternative reverse osmosis. around 35 g of salt (sodium chloride) source that provides a solution In the 12th century, Adélard de 1978: start-up of the first seawater per liter that is 3.5% of the water’s Bath described two experiments in to water needs now and for the desalination plant using reverse weight, and can vary depending on future.” Quœstiones naturales : “In the osmosis, in Jeddah, Saudi Arabia. sun, after evaporation on a rock, the climate: 7g/l in the Baltic Sea, 270g/l in the Dead Sea. Antoine Frérot seawater is transformed into salt; President, Veolia Water when the sun is absent, seawater The distribution of the remaining is heated and under the effect of 3% (freshwater) is very uneven: cooking, it can also be observed to 10 countries share 60% of the transform into salt. This metamorphosis explains that the reserves, while 29 others (in Africa, sea is saltier in summer than and the Middle East) face chronic winter, and that the southern seas shortages. Contents are saltier than the northern seas.” Page 1 The desalination of seawater is a From ancient times, sailors have I Of strategic importance solution that increases the available desalinated seawater in simple by Antoine Frérot freshwater resources, provides a boilers on their boats, but such use Did you know? solution in the event of drought, I on an industrial scale is recent. Key information and for coping with shortages and I I Research objectives Aristotle crisis situations. Page 2 I Need to know about… Research objectives Page 3 Essentially focused on the process of reverse osmosis, Veolia Environnement’s research aims I Close-up on Research and Development programs to optimize the operation of desalination plants utilizing membrane processes. The research is focused on two main aspects: Page 4 I Pretreatment of the seawater to limit membrane clogging further down in the treatment I For more information… process; I Video fact sheet I Reducing the energy expenditure to cut the cost of desalination and improve the I Contact environmental outcomes.
Michel Dutang Director of Research, Development and Technology, Veolia Environnement. “Veolia Environnement Research and Development is working on making desalination an alternative solution accessible to the greatest number both technologically and economically.”
Seawater desalination
Need to know about… Seawater is an inexhaustible resource, but it What is a membrane? contains 1,000 times the salt set by the WHO for human consumption. The membrane is a flat surface with selective permeability. Its main role is to remove salt. It The most frequent seawater also retains undesirable components in the desalination techniques water (micro-algae, bacteria, certain viruses, Distillation or thermal desalination micro-organisms, and micro-pollutants), The seawater is heated to evaporation. Only overcomes turbidity (cloudy water), limits the water molecules are driven off, leaving disinfection by-products, and results in the behind a deposit of salt and other substances. production of treated water. The vapor is condensed to produce freshwater. In the case of reverse osmosis, the removal of undesirable physical-chemical biological Reverse osmosis or membrane Desalination compared with river elements is virtually total. water treatment: desalination: the seawater is forced under pressure through a membrane filter. The salts What is reverse osmosis? Upsides and microorganisms are retained by the I Alternative solution to the membrane. This process does, however, Osmosis is a principle found in nature. If two shortage of water require preliminary treatment of the water. aqueous solutions with different saline I Fewer chemical reagents concentrations are separated by a membrane, I Less sludge produced Today, these two techniques roughly share half the water spontaneously passes through the I Less costly civil engineering the global market each. Between 1990 and I Constant treated water quality membrane from the solution with the lower salt 2001, the market share of reverse osmosis concentration to the solution with the higher rose from 40 to 53%. Veolia Environnement’s concentration. Downsides research has focused on reverse osmosis, as I High energy consumption its market share is predicted to climb to 70% Reverse osmosis is based on the reverse of I Cost still high (compared with 20% for thermal desalination this principle. It consists in applying a high I Volume of water produced and 10% for other methods) by 2020. pressure to the salty water, which entails high insufficient compared with the volume of seawater treated energy consumption, to force it through a I Disturbance to the marine All the characteristics of the seawater to be membrane. Under this process, only the water environment from extraction and desalinated need to be taken into account in molecules pass through the membrane, reject water with a very high salt selecting the process operation parameters to thereby producing freshwater. content control aspects, such as corrosion, deposits and costs. • Module spiralé PièceSpacer TubPerforatede collecteur header perforé tube d ’écartement MembraneMembrane MembraneMembrane ConcentratConcentrate SortiePermeate perméat outlet AlimentationInfeed PrePressuression
Eau EauTreated pure ConcentratConcentrate water+ Seawaterde + InfeedAlimentation through au travers mer eaufiltered de mer seawater thede l’écarteurspacer MembranesMembranes filtrée H O Ecarteur du canal SeawaterEau 2 Infeed H2O dchannel ’alimentation spacer de Treated mer LeThe perméat permeate est drainé Eauwater pure Description of a reverse is endrained spirale around vers le osmosis spiral module. the spiralcollecteur to the header OSMOSISOSMOSE REVERSEOSMOSE OSMOSISINVERSE
Page 2 / The magazine of the scientific chronicles / No. 4 / July-August 2005 / Seawater desalination
Seawater desalination Pilot filtration unit in Perth (Australia).
Close-up on Research and Development programs
Veolia Environnement Research and Pretreatment research Development is basically working on defining the treatment process, in Research is currently underway at Cape particular, the water’s pretreatment to Sicié in Toulon (France). The aim of this reduce energy costs. study is to optimize the performance of filtration processes used for seawater pretreatment. Membrane research The membrane is the key component in These trials will provide precise reverse osmosis facilities. Its replacement knowledge about the impact of the various represents 5% of treatment costs. parameters on the quality of the Membrane separation (or osmosis) has pretreated water (filtration rate, depth of Desalination pretreatment pilot installation in Tawellah one weak point: membrane clogging. the filtering media beds, etc.). (United Arab Emirates) The aim of the Membrane Center of Tests have also been carried out (between Expertise (ARAMIS), created in 2004 at February and August 2004) at the Abu Anjou Recherche (Veolia Environnement’s Dhabi site (Saudi Arabia), as part of an water research center) is to identify the industrial project. The pilot study has Membrane clogging matter responsible for clogging, and demonstrated the effectiveness and recommend efficient and durable robustness of the pretreatment solutions The deposit of material leads to adopted. the formation of a layer on the treatment solutions (pretreatment and appropriate cleaning cycles). membrane surface, which These processes achieve excellent reduces the filtration flow rate and consequently the module’s A thesis at the University of Poitiers results, as they remove between 90 and performance. Clogging is the (France) and the Banyuls Oceanographic 99% of the solid particles and almost all cause of membrane ageing in Institute (France) aims in particular to the microorganisms. three out of four cases. identify the compounds liable to clog reverse osmosis membranes.
Advantages of membrane processes (for the production of drinking water from seawater)
Above all, it reduces by a factor of 3 or 4 the energy consumed compared with thermal desalination. Nonetheless, Veolia Environnement researchers are working on improving certain points: I Managing waste (concentrate) to improve the environmental results, I Increasing yield: the volume of water extracted is 2 to 3 times that of the volume of drinking water produced by desalination, I Controlling clogging phenomena, I Reducing operation costs.
Page 3 / The magazine of the scientific chronicles / No. 4 / July-August 2005 / Seawater desalination
Seawater desalination Fanny Demulier, Steeve Sierra, Martin Geisler, Pierre-Yves Maurie and Hervé Suty.
For more information…
Video fact sheet Partnerships Publications Impact of conventional pretreatment, prior to The Scientific Chronicles No. 4 Organic matter characterization I I reverse osmosis desalination membranes, on ESIP Poitiers Log onto the Group Intranet to view the 4-minute the fouling potential of seawater esip.univ-poitiers.fr video about the research carried out by Veolia LCEE/ESIP UMR CNRS 6008 Université de Environnement on seawater desalination. Poitiers,France. Sophie Rapenne et Hervé Gallard. I Marine environment characterization Observatoire Océanologique de Banyuls, Université Observatoire Océanologique de Banyuls-sur-Mer Pierre et Marie Curie, UMR CNRS No 7621 and Expert: Hervé Suty www.obs-banyuls.fr/ 7628, Banyuls-sur-Mer Cedex, France. C. Courties, Director of Anjou Recherche, J.-P. Croué, P. Lebaron Veolia Environnement Group I Electrochemistry and characterization of Anjou Recherche, Veolia Water Research Center Witness: Pierre-Yves Maurie membrane surfaces Maisons-Laffitte – France Sophie Rapenne, Jérôme Writer, RMTT – Veolia Transport Université d’Angers : GIRPA Beaucouzé Leparc Scenario: Marie-Odile Monchicourt / www.univ-angers.fr Publications presented at AWWA Membrane 3B Conseils Technology Conference, Phoenix, United States, Duration: 4 minutes 30 seconds I Decision-making tools March 2005. Ecole Polytechnique Fédérale de Lausanne, When: June 10, 2005 energy, and GIRPA, behavior of I Tools for membrane autopsies and antifouling Where: Amphitria, Cape Sicié. pollutants in the environment. strategies in seawater feeds (review) SIRTTEMEU, Générale des Eaux www.epfl.ch University of Angers, UMR-MA105, Laboratoire des Preparation: Fanny Demulier, Sciences de l'Environnement et de l'Aménagement, Anne Dequeker-Cormont, Sites currently operating: M. Pontie, A. Thekkedath, J. Duchesne, Caroline Bellecourt, Edith Weitz several references University of Poitiers, LCEE/ESIP UMR-CNRS Research, Development and 6008, Sophie Rapenne Technology Communication Anjou Recherche, Veolia Water, Valérie Jacquemet, Department Veolia Environnement I Palma de Majorca (Spain) Jérôme Leparc, Hervé Suty. Directors: Steeve Sierra, Martin Geisler I Abu Dhabi (United Arab Emirates) I Ashkelon (Israel) Delegate producer: I La mer, terreur et fascination, Bibliothèque Bruno Plasse, Dawa Productions Nationale de France, Seuil 2004 Magazine design and production: 3B Conseils Documentary resources Photo credits Graphic design: Bernadette Coléno/3B Conseils Veolia Environnement Barthélemy l’Anglais, Livre des propriétés des Producer: Veolia Environnement choses, photograph from the publication, La mer, Audiovisual terreur et fascination, Bibliothèque Nationale de Date released online: August 2005 I The scientific chronicle No. 4: France, Seuil 2004 (cover). Seawater desalination (see box) Thanks to Philippe Rey Engineer, Philippe Marteil I Veolia Environnement Video conference on and Jean-Christophe Schrotter, Program Ashkelon in Israel by Bruce Durham, Veolia Regulatory context Directors, Anjou Recherche and the teams Water, AFAS – 50th anniversary of CERN EU Water Framework Directive (WFD) of at Veolia Water in Cape Sicié, France. http://agenda.cern.ch/askArchive.php, May 2004 December 22, 2000, transposed into French Law Brochure : Developing alternative resources. by the Law of April 21, 2004 Desalinating seawater Water Bill - Bruno Sido
The previous scientific chronicles Specialized websites Contact 1 – Legionella www.edsoc.com 2 – The biroreactor European Desalination Society Department of Research, Development 3 – Fuel cells www.cea.fr and Technology Atomic Energy Commissariat 36, rue de Liège 75008 PARIS - France www.veoliawatersystems.com Tel.: +33 (0) 1 71 75 06 60 Veolia Water Fax.: +33 (0)1 71 75 10 40 www.commission-europeenne.fr Mail: [email protected] European Commission Page 4 / The magazine of the scientific chronicles / No. 4 / July-August 2005 / Seawater desalination