1 Economic and technical assessment of desalination technologies Fawzi Banat Jordan University of Science and Technology Jordan Geneva 6-8 June, 2007
2 John F. Kennedy had said If we could ever competitively, at a cheap rate, get fresh water from saltwater,..(this) would be in the long-range interests of humanity which could really dwarf any other scientific accomplishments. (September 22, 1961)
3 Outline of the talk A global overview of desalination The trends of costs of desalination
4 Introduction to desalination 97% of the earth s water is seawater salt content ~ 35,000 mg/liter Domestic water supply requires: Dissolved solids content <1000 mg/l Drinking water < 500 mg/l Desalination refers to the wide range of technical processes designed to remove salts from water.
5 Quality categories for water salinity Use Human consumption Human consumption Human consumption Human consumption Irrigation Rating Excellent Good to fair Poor Unacceptable Maximum for healthy growth Approximate salinity (mg/l) < ,000 1,000-1,200 >1200 3,500
6 Introduction Why go for desalination o Potable water shortage o Growth of technology and industrial demand for pure water, ( Power Plant, Petroleum, Food and Medical Industries, etc.) o The ongoing deteriorating quality of fresh water sources o The reduced cost of water produced by desalination.
7 Consumers Desalination has developed rapidly, and is an important source in parts of Middle east Arabian Gulf North Africa and some islands as well, become increasingly explored by many other regions as well
8 Chart showing fraction of the worldwide capacity of desalination plants by region SOURCE: Wangnick, 2002.
9 Desalination Saline Water (Brackish or sea water) Energy Desalting Device Fresh water Brine
10 Desalination Processes Thermal mimic natural water cycle, produce water vapor, then condensed to form fresh water Commercial plants with multi stage Concept Multi Stage Flash (MSF) Multi Effect Distillation (MED) Vapor Compression (VC) Normally are used for seawater desalination, because of the high energy requirements for vaporization (phase change)
11 Thermal desalination
12 Membrane Processes o Need to produce water without involving phase change to reduce energy consumption o Membranes needs electrical energy or shaft power o Two processes emerged: Reverse Osmosis for seawater and brackish water Electrodialysis for brackish water only
13 Alternative processes o Renewable energy powered conventional desalination o Solar humidification o Freezing o Membrane distillation
14 Principles of desalination
15 Source of energy o Fossil Fuel CO 2 emission, costly o Renewable Energies Still high cost
16 Multistage Flash Distillation (MSF) o It was invented in 1950 o First MSF plant was build in 1957 in Kuwait o MSF is thermodynamically inefficient process o MSF is matured and mostly used in the Middle East o Capital cost is US$ 5 to 6 per installed gallon/day o Desalinated water cost is US$ 0.8 to 1.5 per cubic meter
17 Multi Effect Distillation (MED) o It is adopted from chemical industry to desalination in 1900 o First MED plant was built in 1930 in Saudi Arabia o MED is thermodynamically efficient process compared to MSF o Capital cost is US$ 3.5 to 4.5 per installed gallon/day o Desalinated water cost is US$ 0.7 to 1.0 per m 3
18 Vapor Compression Distillation o The operating costs are low compared to multi-stage or multi-effect flash distillation systems o The equipment is smaller than the multi-stage flash or multi-effect flash distillation systems o maintenance on compressors and heat exchangers is greater than those of other systems
19 Reverse Osmosis (RO) o Has been used commercially since 1982 o Membrane costs have fallen by 86 percent between 1990 and 2002 (Chaudhry, 2004) o In fact, 2005 unit cost of SWRO are only about a third of 1995 unit cost
20 Review Thermal processes are generally used in the following applications: o To treat highly saline waters (predominantly seawater) o Where large volumes of product water are required. o In locations where energy costs are low or where a waste heat source is available.
21 Review Membrane processes, on the other hand, are more favorable for treating brackish waters (under most conditions) or highly saline wastes where energy costs are high or the flow rates are low.
22 Advantages of RO o Quick and cheap to build and simple to operate o Handle a large range of flow rates o Energy consumption is low o High overall water recovery rates o The startup and shutdown of the process does not take long.
23 Seawater Reverse Osmosis Plant Flow Chart
24 Comparison thermal vs. membrane Energy Consumption Recovery Investment [$/(m 3 /day)] Chemicals [$/m 3 ] Brine Quantity Brine Quality Robustness Improvement Potential MSF ~13 kwh el /m 3 (70 kwh th + 3 to 4 kwhel) 10% - 20% ~ 1,000 1,500 ~ 0.03 to 0.05 Distillate x 4 to 9 Chemicals, Heat High Low RO 4-5 kwh el /m³ 30% - 50% ~ 7,00 1,500 (10% for membranes) ~ 0.06 to 0.1 Permeate x 1 to 4 Chemicals Fouling Sensitivity, Feed water Monitoring High
25 Factors Influencing Selection of Desalination Technologies o Financial issues. o Energy Requirements. o Source water characteristics. o Geographical and location constraints. o Product water requirements. o Environmental factors and waste disposal options. o Operational and maintenance issues o Utilization rates.
26 Costs of desalination Capital costs direct costs purchase of equipment, land, construction charges and pre-treatment of water indirect costs interest, insurance, construction overheads, project management and contingency costs Annual O&M costs labor, energy, chemicals, consumables and spares
28 Desalination Technologies
29 World desalination capacity Waste 6% Pure 6% Others 1% River 7% SEA 55% Brackish 25% by raw water quality
30 Economics of Desalination Source: Kaufler
31 Cost Evolution of the SWRO Process
32 Cost composition for a representative seawater MSF plant Source: Ebensperger and Phyllis Isley (2005)
33 Cost composition for a typical seawater RO plant Source: Ebensperger and Phyllis Isley (2005)
34 Cost with relative to RO Cost component MSF MED MVC RO Capital investment Energy related costs Membrane replacement Other remaining costs Overall product cost
35 Total capacity of desalination plants worldwide by type of technology used SOURCE: Wangnick, 2002.
36 Trends in Desalination Technologies o Reverse Osmosis world-wide dominates new installations of desalination capacity o New thermal plants restricted to Gulf Region (MED with largest improving potential) o Availability of temperature-resistant RO- Membranes? Potential for Gulf Region o Reduction of energy costs (approx % of water production costs!!) by: Increasing energy efficiency (RO, energy recovery) Increasing substitution of fossil by renewable energy systems (RES) expected
37 Zhou and Tol analysis Data from IDA Worldwide Desalting Plants Inventory Report No.17 Contain about 3000 data points from 1950 up to 2003 for MSF and RO Data include country, location, total capacity, units, process, equipment, water quality, user, contract year and investment costs.
38 Costs analysis of MSF Unit cost ($/m3) Year
39 Costs of desalting by MSF o The unit costs declined over time from 9 $/m 3 to 0.9 $/m 3 in 2000 o Based on the exponential projection presented in the figure, the average cost will go down to about 0.3 $/m 3 in (Associated with great uncertainty)
40 Developments of RO process RO became more popular during the last decades Operating costs reduced: o lower-cost, higher-flux, higher saltrejecting membranes that can operate efficiently at lower pressures o use of pressure recovery devices
41 6.0 Costs analysis of RO (converted to 1995 base year level) 1995 Unit cost($/m3) Waste Sea 1.0 Brackish Year
42 Costs of desalting by RO Unit costs vary with: o Raw water quality o Location o Capacity RO today o 0.6 $/m 3 brackish or wastewater o 1.0 $/m 3 seawater - become lower with time, especially RO
43 Conclusions Improved desalination technologies have been playing important roles to reduce the unit cost of water noticeably over time. To date, the average cost of desalted water using MSF has been reduced to about 0.9 $/m 3 (seawater) and RO to 0.5 $/m 3 (brackish), very competitive for traditional water resources
44 Conclusions Desalination can provide reliable water supply and will be economically feasible, therefore it is requested to invest in and undertake consistently research on brine disposal.
The Grand Miramare Hotel Santa Margherita (Portofino) Italy March 19 22, 2013 Inspiring Innovation and Excellence About the IDA Desalination Academy The IDA Desalination Academy aspires to increase knowledge
Promotion of Solar Desalination in the MENA Region Koussai Quteishat and Mousa Abu-Arabi Middle East Desalination Research Center Muscat, Oman Abstract Desalination has become one of the sources of water
European CO-OPET Commission Support initiative for the Organisations for Promotion of Energy and Transport Technologies Work package no. 7: Water and Power co-generation in the Mediterranean islands and
General Presentation Contents 1. COMPANY PROFILE 1.1 Veolia Environnement 1.2 Veolia Water 1.3 Sidem History: From Multi Stage Flash... 1.4... to Multiple Effect Distillation 1.5 Worldwide Capacity installed
Sea water desalination: thermal desalination vs membrane Gazzani Matteo, 20.11.2015 1 Water Desalination Desalination: process of removing dissolved solids, such as salts and minerals, from water. Historical
Differentiation Summary Revolutionizing Water Clean-Up Opportunities NanoClear is a water clean-up process that affordably and efficiently converts salt, brackish or waste water into pure, usable water.
TECHNOLOGY of REVERSE OSMOSIS DESALINATION Mitsuyoshi HIRAI, Managing Director WATER REUSE PROMOTION CENTER, JAPAN 16 th December, 2014 at Kuwait 1 CONTENTS 1. Classifications of Desalination Technologies.
Solar Energy Desalination: Co-generation of water and electricity Costas N. Papanicolas The Cyprus Institute 1 Global Fresh Water Stress Cyprus, like many other islands in the Mediterranean and MENA region
Jan C. Schippers November 2011 Chile 22/11 Water consump.on and water cycle, 2008 Direct and indirect water consump>on equals: Abstrac>on: 9,000 10 9 /m 3 year. 4,000 10 9. Precipita>on on land: 100,000
79 Renewable Energy Applications in Water Desalination Professor Ali Al-Karaghouli is currently a Principal Research Engineer dealing with renewable energy applications and science and technology partnerships
FUJAIRAH 1 INDEPENDENT WATER & POWER PLANT (F1 IWPP), UNITED ARAB EMIRATES Fujairah 1 Seawater Reverse Osmosis Expansion Innovative Energy and Water Resources Management Presentation by William Chang Executive
6 Seawater Desalination: Trends and Technologies Val S. Frenkel, Ph.D., P.E., D.WRE. Kennedy/Jenks Consultants, USA 1. Introduction Figure 1 below provides information on our planet s available water resources
35 th Discussion Forum «Assessment of Water Use within LCA» ETH Zürich, 05/06/08 LCA-based tool on potable water supply and further inputs for the LCA of water use François Vince Veolia Environnement R&D
The Economics of Desalination for Various Uses Carlos Campos Index 1. Introduction 2. Available desalination technologies 1. Desalination by MSF 2. Desalination by RO 3. Comparison of large scale desalination
Mobile units for your water supply Reliable water supply Rapidly deployable Hatenboer-Water Fresh in water since 1906. Water treatment & services With specialist expertise, in-house engineering, design
DESALINATION & SUSTAINABILITY: RENEWABLE ENERGY DRIVEN DESALINATION AND BRINE MANAGEMENT D.A. Xevgenos *, K. Moustakas, D. Malamis, M. Loizidou Unit of Environmental Science and Technology (UEST), School
Tech Fact FILMTEC Membranes Strategies for Using FILMTEC Elements to Lower Your Total Cost of Seawater Desalination As demand for drinking water continues to increase particularly in regions of the world
Seawater Desalination Menachem Elimelech Department of Chemical and Environmental Engineering Yale University 2012 NWRI Clarke Prize Conference, Newport Beach, California, November 2, 2012 The Top 10 Global
DESIGN AND SETUP OF A HYBRID SOLAR SEAWATER DESALINATION SYSTEM: THE AQUASOL PROJECT Diego Alarcón Julián Blanco Sixto Malato M. Ignacio Maldonado Pilar Fernández CIEMAT - Plataforma Solar de Almería Ctra.
Sustainable Reverse Osmosis Desalination Sasan Moridpour B. Eng. Submitted in fulfillment of the requirements for the degree of Master of Engineering School of Aerospace, Mechanical and Manufacturing Engineering
ICDEMOS, 13 16 April 2014, Sultan Qaboos University, Muscat, Sultanate of Oman 1/40 Desalination Process Advancement by Hybrid and New Material beyond the seahero R&D Project In S. Kim Global Desalination
A dual purpose nuclear power plant using FBNR Guilherme Varella Federal University of Rio Grande do Sul, Porto Alegre, Brazil firstname.lastname@example.org ABSTRACT The adequacy of nuclear reactor FBNR for nuclear
Aquatech Seawater Reverse Osmosis System at Ghalilah, Ras Al Khaimah, United Arab Emirates In 2014, the Federal Electricity and Water Authority of the United Arab Emirates, in EPC partnership with Aquatech
IWC-00-15 INTERSTAGE ENERGY RECOVERY TURBINE APPLICATION MARCO ISLAND, FLORIDA JULIA NEMETH, PE Harn R/O Systems, Incorporated Venice, Florida STEVEN DURANCEAU, PHD, PE Boyle Engineering Corporation Orlando,
Pall Aria Integrated MF/RO Systems for Cost-Effective Treatment of Sea and Brackish Waters Pall Aria Integrated MF/RO Systems for Cost-Effective Treatment of Sea and Brackish Waters Water scarcity resulting
Twelfth International Water Technology Conference, IWTC12 2008 Alexandria, Egypt 1 RENEWABLE ENERGY POWERED DESALINATION SYSTEMS: TECHNOLOGIES AND ECONOMICS-STATE OF THE ART Mohamed A. Eltawil 1,2, Zhao
Prof. Maria Loizidou National Technical University of Athens (NTUA) email@example.com 1 BRAWA Project Development and implementation of an innovative, brackish water treatment pilot plant for the production
GE Power & Water Water & Process Technologies Water and Process Solutions for the Refining Industry Maximizing Refining and Fuel Production Processes For more than 100 years, GE has maintained its commitment
OPERATION STRATEGIES FOR A SMALL SCALE PHOTOVOLTAIC REVERSE OSMOSIS DESALINATION PLANT IN GRAN CANARIA Dirk Herold, Apostolos Neskakis Aachen University of Applied Sciences, Ginsterweg 1, D-52428 Jülich,
Economic and Technical Analysis of a Reverse-Osmosis Water Desalination Plant using DEEP-3.2 Software Ali Al-Karaghouli and Larry Kazmerski National Renewable Energy Laboratory Golden, Colorado 80401 Abstract
Guidance Leaflet Reducing water use softeners and reverse osmosis Most water supplies contain dissolved solids (e.g. salts and other minerals, particularly calcium and magnesium). The type and level of
Feasibility Study of Brackish Water Desalination in the Egyptian Deserts and Rural Regions Using PV Systems G.E. Ahmad, *J. Schmid National Research Centre, Solar Energy Department P.O. Box 12622, El-Tahrir
Desalination and Advance Water Treatment Economics and Financing Corrado Sommariva Corrado Sommariva ISBN 0-86689-069-6 LOC 1 Contents 1 Contents 2 2 Foreword 5 3 Introduction 8 4 Going through the book
ing Solutions for Desalination and Water Reuse 2 Experience and Proven Technology As a global leader in pump design and manufacture, Sulzer is recognized for delivering the excellent product quality and
DESIGN CHALLENGES AND OPERATIONAL EXPERIENCE OF A MEGA MED SEAWATER DESALINATION PLANT IN TIANJIN Authors: Presenter: T. Efrat, Yu Haimiao Tomer Efrat Deputy Manager, Thermal Process Dept. IDE Technologies
Danfoss AquaZ Drivers of Opportunity Potable Water Scarcity High Water Desalination Costs Danfoss AquaZ Value Proposition Our Solution: The Cost-Effective Aquaporin Membrane The Current RO/NF Market and
ECONOMIC ANALYSIS OF A WIND POWERED REVERSE OSMOSIS DESALINATION SYSTEM IN TAN-TAN, MOROCCO Driss Zejli Centre National pour la Recherche Scientifique et Technique (CNRST) CNRST Centre National pour la
An EconoPure White Paper 2024 N. Broadway Santa Ana, CA 92706 USA 1+(714) 258 8559 www.econopure.com Point of Use/Point of Entry Treatment with LFNano By: Curt Roth Vice President, Engineering EconoPure
Desalination of Seawater by Reverse Osmosis The Malta Experience Introduction Malta, an archipelago of three islands situated 50 miles south of Sicily in the middle of the clear blue Mediterranean Sea,
Integrated Hybrid Desalination Systems Leon Awerbuch President, Leading Edge Technologies, Ltd., Winchester, MA USA, E-mail firstname.lastname@example.org It is great opportunity to take part in discussions on Innovations
Economics of desalination concentrate disposal methods in inland regions: deep-well injection, evaporation ponds, and salinity gradient solar ponds By: Robin A. Foldager A thesis submitted to the University
KEMIRA MEMBRANE PROGRAM EFFICIENT WATER TREATMENT WITH MEMBRANE PROTECTION TRANSFORMING RAW WATER INTO DRINKING WATER SEAWATER DESALINATION Drinking water is a scarce resource in many parts of the world.
Solar photovoltaic-powered membrane distillation as sustainable clean energy technology in desalination GENERAL ARTICLE S. R. Selvi* and R. Baskaran The present article discusses the application of a new
Environmental Science 101 Energy Fall 2012 1 Lecture Outline: 7. NON-RENEWABLE ENERGY RESOURCES A. Energy Sources and Uses in USA B. Current Consumption, Uses and Costs 1. Consumption 2. Energy Costs C.
Innovative Applications of Renewable Heating and Cooling Executive Summary... 3 Introduction... 4 Scope of this document... 4 Industrial process heat... 5 Introduction... 5 Examples... 5 Specific barriers
Tech Fact Lenntech email@example.com Tel. +31-152-610-900 www.lenntech.com Fax. +31-152-616-289 FILMTEC Membranes How FilmTec s New High-Rejection, Low-Energy Seawater Element Can Reduce Your Desalination
CENTRAL ARIZONA SALINITY STUDY ---- Phase I Technical Appendix O Municipal TDS Research Introduction Water availability and quality are among the world s most important environmental issues. Demand for
Case Study: Optimizing Scale Inhibition Costs in Reverse Osmosis Desalination Plants Mohannad Malki, American Water Chemicals, Inc. Abstract Over the last few decades, advancements in technology and engineering
Alternative and Renewable Energy Christopher Nicholson section: AD Last 4 # of SIN: 5001 Current Primary Energy Sources Current Primary Energy Sources The pie chart on the left depicts global sources of
ELECTROCHEMICAL WATER TREATMENT PILOT PLANT IN THE DAIRY INDUSTRY WITH PHOSPHATE RECOVERY The Project leading to these results has received funding from the EACI by the Eco-Innovation programme under grant
Wastewater Reuse Most metal finishing industries have in-house wastewater treatment to economically dispose of the acids, alkali, oils, and dissolved metals in the rinse water and occasional tank solution
ENERGY TECHNOLOGY SYSTEMS ANALYSIS PROGRAMME IRENA International Renewable Energy Agency Water Desalination Using Renewable Energy Technology Brief IEA-ETSAP and IRENA Technology Brief I12 March 2012 www.etsap.org
MICROFILTRATION AND ULTRAFILTRATION Ata M. Hassan Saline Water Conversion Corporation, RDC AlJubail, Saudi Arabia Kevin Price U.S. Bureau of Reclamation, Denver, U.S.A. Keywords : Filtration, Media filters,
FORWARD OSMOSIS DESALINATION: A COMMERCIAL REALITY Authors: Neil A. Thompson, Peter G. Nicoll Presenter: Neil Thompson, Technical Development Manager Modern Water United Kingdom Abstract Modern Water is
ASSESSMENT OF WASTEWATER TREATMENT AND WATER REUSE PRACTICES IN THE GULF COUNTRIES Mohamed F. Hamoda Professor of Water Resources and Environmental Engineering Department of Civil Engineering, Kuwait University
Mechanical Heat Pumps Using Water as Refrigerant for Ice Production and Air Conditioning Case studies Avraham Ophir IDEA 99 th Annual Convention, Orlando, Florida, 2008 IDE was founded in 1965 To Develop
Flow Configuration There are several flow configurations for RO that allow the user to get the most out of the system. This paper will cover a few of the techniques used in RO design to optimize system
The Role of Desalinated Water in Integrated Water Resource Management in Abu Dhabi Emirate-UAE Muthanna Al-Omar Environmental Studies Dept., National Energy & Water Research Center Abu Dhabi Water & Electricity
PAPER NO: CATEGORY: TP12-06 COOLING TOWER WATER CHEMISTRY COOLING TECHNOLOGY INSTITUTE FORWARD OSMOSIS APPLIED TO EVAPORATIVE COOLING MAKE-UP WATER PETER NICOLL NEIL THOMPSON VICTORIA GRAY MODERN WATER
Desalination of Seawater by Reverse Osmosis April Youn Fall 2010 Simon Fraser University November 19, 2010 Presentation Outline Composition of seawater What is reverse osmosis Pre treatment of feed water
Saline Water Conversion Corporation s Investment Opportunities for New Projects in KSA Presented by Eng. Abdullah Al-Breakeit Deputy Governor for Projects and Technical affairs SWCC Desalination Plants
Written Testimony of Richard L. Stanley Vice President, Engineering Division GE Energy Before the Subcommittee on Energy and Environment Committee on Science and Technology U.S. House of Representatives
Aquatech CORPORATE PROFILE From Innovation Flows Leadership INNOVATING TO CR EATE VALUE for Industry, Infrastructure and the Environment Aquatech is dedicated to bringing the most valuable solutions and
Electronic Theses and Dissertations UC San Diego Peer Reviewed Title: Solar powered desalination system Author: Mateo, Tiffany Alisa Acceptance Date: 2011 Series: UC San Diego Electronic Theses and Dissertations
RENEWABLE ENERGY MIX FOR EGYPT Hani El Nokrashy, Dr.-Ing. NOKRASCHY ENGINEERING GmbH An de Masch 24 D-25488 Holm (Hamburg) Germany e-mail: HN@ nokrashy.net web site: http://www.nokrashy.net Abstract: Due
Desalination Efficiency: Energy, Water and Other Resources Technical Paper Author: William Harvey Desalination Commercial Development Leader GE Water and Process Technologies Enviro 2008 Conference, May
Industrial Water Reuse Case Studies Published in IWA Newsletter of the Specialist group on Water Reuse. November 2005. Josef Lahnsteiner 1 and Ferdinand Klegraf 1 1 VA TECH WABAG GmbH, Siemensstrasse 89,
Technical Paper Seawater Reverse Osmosis Plants in the Caribbean Recover Energy and Brine and Reduce Costs Authors: Shawn Meyer-Steele, Antonia von Gottberg and Jose Luis Talavera Introduction With continued
Solare termico altre applicazioni G.V. Fracastoro CSP per produzione elettrica Usati in combinazione con un impianto a ciclo termodinamico (Rankine o Stirling) point concentration systems (parabolic reflectors)
Regulatory Options for Membrane Treatment and Residuals Management Background Over a period of several years, Colorado s Water Quality Control Division (Division) received requests for discharge permits
Innovative Designs of the UF& SWRO Limassol Desalination Plant in Cyprus N. Nadav, Mekorot Water Co., The Projects' Design and Commissioning Engineer, Lincoln str. 9 Tel-Aviv Israel, firstname.lastname@example.org
Case History High Turbidity and Temperature Fluctuation No Obstacle for Site Information Location: HeBei, China Capacity: 12 m 3 /h (5283 gpm) Purpose: Pretreat sea water prior to RO system Time in Operation:
European Desalination Society Desalination with Solar Energy A 3-day intensive course June 11 13, 2014, Almería, Spain Almeria2014_A5.indd 1 Introduction Desalination of sea and brackish water is a common
State of Qatar Ministry of Environment Intended Nationally Determined Contributions (INDCs) Report November 19 th, 2015 State of Qatar is pleased to submit its Intended Nationally Determined Contributions
Water Softeners Industrial Water Purification (800) CAL-WATER By Dave Peairs, Cal Water, Technical Director Rev: 06/08/2004 Before any discussion of water softeners, we must first define what hard water
Performance Monitoring & Optimization Fujairah Water and Power Plant Basic infrastructure like Power and Water production has come into focus due to the rapid growth witnessed in the Middle East. Hybrid
MEMBRANE TECHNOLOGY TREATING OILY WASTEWATER FOR REUSE Jeff Peeters, P.Eng. ZENON Environmental Inc. SAWEA 2005 Workshop Al-Khobar Holiday Inn Hotel, Saudi Arabia November 29, 2005 Presentation outline
Promotion of Renewable Energies for Water Production through Desalination www.prodes project.org Commercial Desalination Products powered by Renewable Energy January 2010 Acknowledgements This publication
Desalination 220 (2008) 37 56 LCA tool for the environmental evaluation of potable water production François Vince a,b *, Emmanuelle Aoustin a, Philippe Bréant a, François Marechal b a Veolia Environnement