Editorial
EDS continues to take a major role in promoting interest in desalination in the European and Mediterranean region. In September we took a leading part in organising the EuroMed conference at Jerba Island in Tunisia. This was followed by the joint IWA/EDS conference in Paris on "Membranes in drinking water and industrial water production", early in October. Both these meetings are reported in this issue.
Previous Newsletters have carried articles on a variety of technical topics. For the next few issues we have decided to run a series of articles on a common theme, broadly covering the different seawater desalination processes. In this issue we start with contributions by authors from Sidem and IDE on multiple effect plants, two of the leading distillation plant manufacturers. Future issues will cover reverse osmosis and membrane topics. I hope to have comparisons between the processes by leading authorities and perhaps stir up some rivalry between the supporters of each process.
It is very sad to have to record the death of two of the European pioneers in desalination and members of the EDS Board. Tom Temperley spent most of his career in the Middle East, while Robert Rautenbach pursued an academic life from his home in Germany. I am sure the members of EDS join in expressing their sympathy and best wishes to the families of both these outstanding leaders in our community.
Our next main event will be the conference on "Desalination and the Environment: Water Shortage", at Lemesos (Limassol) in Cyprus from 27 to 31 May 2001. Details were given in the recent call for papers and second announcement, and this promises to be another first class event, with strong backing from the local authorities. We are already starting to plan the next conference in this series, in Malta in 2003. We are also planning to hold a second meeting in the EuroMed series in Egypt in 2002 and a third in Morocco in 2004.
Neil Wade, Editor

EDS Board 2000-2002

Bill Hanbury, President
Jan Schippers, Vice President, Programs
Miriam Balaban, Secretary
John Allanson, Treasurer
Ursula Annunziata, Membership, Exhibits
Klaus Genthner
Peter Moss
Antoine Riolo
Corrado Sommariva, Constitution
Jean-Michel Laîné

Neil M. Wade

Prof. Thomas Melin

Early days
Before about 1960, sea water distillation processes MSF and MED were already used. In general these former ME evaporators had submerged tubes, characterised by poor heat exchange coefficients. But in order to reduce the specific heat consumption it is desirable to use more than one effect and to increase the number of effects as much as possible. However due to the low heat exchange coefficients the working temperature difference between the effects was rather high, say 5 to 10°C which leads to top brine temperatures of 70°C and even more. As a result the scaling and hence the corrosion of these old ME units were important, and their reliability was not satisfactory at all.
Development of MSF
Then, in the early sixties the MSF process was developed and it was able to better control the scaling problems. In only a few years the old ME technique was almost completely abandoned in favour of MSF evaporation. The large use of MSF allowed progressive improvement of various technological aspects like material choice, scale inhibition, vacuum and process control.
Due to the good performance of MSF, sea water desalination became more and more popular for solving water shortage in the concerned coastal areas ó in particular the Middle East and North Africa.
In order to further reduce the cost of desalinated seawater, it was tempting to find a process which would combine good reliability equal to that of MSF, more simplicity, lower electrical consumption and less investment cost.
Introduction of modern ME distillation
Thus about 30 years ago the modern multiple effect distillation was introduced with two basic improvements:
ó Enhanced heat transfer
ó Limitation of the top brine temperature to a safe 
operating range
Enhanced heat transfer was achieved by horizontal heat tube bundles evenly wetted by spray nozzles, which in addition ensures instant degassing, thus reducing seawater aggressiveness. Needless to say that the even seawater distribution by suitable spraying devices is a key point for this technique.
With the heat transfer coefficient under control, it is possible to keep the top brine temperature i.e. the evaporating brine temperature in the hottest effect under the point where the bicarbonate decomposition which is responsible for the scaling becomes too rapid. With the feedback gained from numerous field experiences over 30 years, including our own water factory in the Caribbean it appears clearly that this temperature limit is at around only 60°C. Obviously this limit of the top brine temperature is the other key point for successful ME distillation.
Achievements in the Gulf Region
In 1973, the first 2 modern MED units were introduced in the Gulf Region at Das Island with a unit capacity of 125 TPD. At the end of the seventies, the unit size had reached 1500 TPD; four of these units were installed at the Ruwais Refinery. Ten years later, at the end of 1989, in order to cope with increasing water demand in remote areas, the Abu Dhabi Water and Electricity Authority selected MED-TVC at low temperature for their developing program on a larger scale (1).
The prevailing terms at selection were reliability, performance, simplicity in equipment, plant life cycle and investment cost.
The first desalination unit of 1 MIGPD capacity was commissioned in December 1991 at Jabal Dhanna, followed by 2 units of 1 MIGPD capacity at Mirfa and 1 unit of 1 MIGPD at Sila.
As a result of the satisfactory operation and performances of these plants (2), 5 more units of the same process were ordered from Sidem and commissioned:
1996 1 unit   1 MGD 
Dalma Island
2 units   2 MGD each 
Jabal Dhanna
1998 2 units  1.5 MGD each 
Ras Al Khaimah
With the exception of Dalma Island, all these plants are located on the seashore having shallow water, high turbidity and summer seawater temperature reaching 38ºC. These coastal configurations and seawater characteristics are the ones prevailing in the Gulf Region.
The plants are stand alone, with seawater intake and pumping facilities, steam boiler, distillate water post treatment and storage.
The yearly availability of the modern MED units is 95% (and more) at 100% of the nominal capacity.

The next step in size was made with the 2 units each of 3.5 MIGPD for the extension of the Umm 
Al Nar West desalination plant (Fig. 1). They are now in operation and have two special features: LP steam is used at a pressure of only 2.8 bar abs. In order to isolate the units from the power plant steam grid, steam transformers receive the primary steam, which is converted into secondary steam to drive the thermocompressors.
In 1999, the modern MED process was selected for the extension of the Layyah desalination plant in Sharjah, resulting in the contract for 2 units each of 5 MIGPD using MP steam and again steam transformers.
Thus modern MED has reached a maturity which has opened the way for its application for large BOT projects in the Gulf Region, as e.g. Taweelah A1 (50 MIGPD) where its high reliability is fully appreciated.

References
(1) T. Michels, Recent achievements of low temperature Multiple-Effect desalination in the western remote area of Abu Dhabi, U.A.E., Desal. 92, Arabian Gulf Regional Water Desal. Symposium.
(2) J.P. Quemion and A. Alexandre. Operation records on low temperature multiple-effect desalination plant in United Arab Emirates Regional Workshop in Bahrain, June 14-15th, 199

Multiple Effect Distillation was the first distillation desalination process developed. The initial configuration used was the submerged tube. The main theoretical drawbacks were:

• Low brine-side heat transfer coefficients.
• Additional temperature drop due to the static head of the brine above the heat transfer surfaces.

• 1. The brine temperature in a MSF process must be heated to a few degrees above the maximum boiling temperature thus increasing the irreversible losses.
• 2. In a MED process, the condensation and evaporation of the ensuing vaporization occur simultaneously across the heat transfer surface. The effective driving force for heat transfer is directly the difference between the condensing and evaporating temperatures. In the MSF process the condensing vapour initially sensibly heats the brine; the effective driving force is the logarithmic temperature difference.
• 3. The MED evaporator is very much less sensitive to flow disturbances, which occur with build-up of scale and fouling.
• 4. Since the brine pressure in the tubes in a MSF evaporator is always above that of the product side, any leakage immediately causes contamination unlike in a MED evaporator, where only a negligible loss of product occurs.
• 5. As the MSF process is based on a forced circulation with as high as practical liquid flow velocities it is far more prone to suffer from erosion. 

On these principles, IDE developed and introduced to the market the Low Temperature Falling Film Evaporator. The most noteworthy of them are the three 1.25 MGD plants in operation since 1981 in the Virgin Islands, for which IDE received the IDEA, Achievement in Engineering Award in 1983 from the International Desalination and Environmental Association. Nineteen years of operation has since shown that these plants richly deserved that award as each and every year these plants (and a further six plants installed later) averaged operating availability exceeding 96% (1).

The size and scope of these plants have also been extended. Two years ago, four 3.17 MGD units were commissioned to supply boiler feed water, containing less than 2ppm TDS to the Reliance Hydrocarbon complex at Jamnagar, India. Currently two 4.62 MGD units have been commissioned at the Telde site, Las Palmas, Gran Canaria, replacing eight MSF units. 
These units were designed to operate on backpressure steam at 1.1 ata, with a performance ratio of 11.1:1. They were designed with such generous fouling factors, that at the acceptance test the unit produced over 5.2 MGD attaining a 
performance ratio of 13.2:1.

Reference
(1) Elovic, P. Willocks, G. Case Study of Operating Experience of 9 Low Temperature MED Plants in the U.S. Virgin Islands, International Desalination Congress, San Diego, CA, 1999.

The recent trend of the Middle East market is showing a renewed interest in Multi Stage Flash desalination, due mainly to the following reasons:

• Very large plant installations require a big unit size above 10 MIGD
• The price of MSF units has been dramatically reduced in the past 3?4 years 
• The efficiency of MSF plants is always above expectations and the requirement for cleaning is often above 4 to 5 years of operation

As far as the unit capacity is concerned we can affirm that the 10 MIGD size is nowadays the standard unit. The following summary shows contracted plants from 1991 up to now of sizes equal or bigger than 10 MIGD:
 

Plant	N° of units	MIGD each
Shoaiba Saudi Arabia	10	10
Al Taweelah B UAE	6	10/12.5
Al Taweelah A2 UAE	4	12.5
Jebel Ali K1 UAE	2	10
Jebel Ali K2 UAE	3	13.33
UmmAl Nar West UAE	5	12.5

The cumulative water production of such large installations covers about 25% of the total contracted water capacity in this period.

New installations which are under evaluation or in tender phase also show this tendency to increase the plant unit size:
 

Plant	N° of units	MIGD each
Ras Laffan Qatar	4	10
Sabyia Kuwait	4 or 8	12 to 15
Shuweihat UAE	6 or 8	16 or 12.5

Not all manufacturers of MSF plants can propose and construct such large units. For the time being only two companies have reliable experience with such large units:

• Fisia Italimpianti (Italy) which at the moment have the largest number of units in service
• Hanjung ( Korea) 

The first EuroMed conference was held on the beautiful island of Jerba in Tunisia. The magnificent Royal Garden Hotel served as the perfect venue for the three-day event. The conference was organised by Mohamed Safi, Laboratoire de Thermique Industrielle de LíEcole Nationale díIngenieurs de Tunis (ENIT) and Miriam Balaban, the European Desalination Society (EDS). Her assistants at the Science Park of Abruzzo contributed greatly to the successful organization of the meeting, and thanks are due also to Prof. Diego Barba, desalination pioneer and President of the Science Park. 
More than 150 delegates attended the conference hailing from every country around the shores of the Mediterranean learned about each otherís needs, problems and capabilities and were eager to find common ground in order to pursue active collaboration. 
The conference opened with introductory lectures from, representatives from ENIT, EDS, IWA and the European Union. 
The technical sessions kicked off with three plenary lectures covering the state-of-the-art in desalting technology. Neil Wade (UK) and Jan Schippers (NL) emphasised the low energy consumption of SWRO systems (3-5 kWh/m3), with a further reduction to 2 kWh/m3 expected in the near future. Cost reductions due to improved membranes, energy recovery systems, system standardisation and micro-/ultrafiltration pre-treatment for BWRO and SWRO plants were projected for the future. Developments in the field of thermal distillation did not go unnoticed and Neil Wade emphasised the increase in MED plant capacities and improvements in the thermal efficiency and flexibility of these systems. In the final presentation in this session, John Walton (USA) stressed some of the new developments in membrane distillation, and particularly interesting was an application involving a membrane distillation system coupled to a solar pond to produce potable water in isolated rural areas. 
The remainder of the first day of the conference focussed on water strategies in the various countries of the EuroMed region. Representatives from Tunisia, Algeria, Morocco, Egypt, Palestine, Jordan, Israel, Malta, and Cyprus spelt out the message that the demand for water is increasing in the EuroMed region due to rising populations, industrialisation and tourism development. The use of new resources e.g. seawater and wastewater to augment existing fresh water supplies were proposed by many of the representatives.
After a hectic first day with over 18 presentations, the second day proved to be just as interesting. Deciding between the parallel sessions on distillation technology on the one hand and membrane systems and electrodialysis on the other was not easy. Promising news emerged from the session on distillation. The lifetime of these plants is expected to increase to 50 years, with material selection being a very important cost parameter to extend plant lifetime and reduce maintenance costs. MED systems employing low temperature industrial waste heat were very promising, as was the use of MED/MSF in connection with small solar ponds in remote areas. Membrane distillation played a prominent role in this session with applications in the field of seawater desalination in conjunction with solar ponds and removal of volatile organic carbon (VOCís) from industrial streams. In the parallel session on membrane filtration, new fouling resistant membranes designed for open intake SWRO systems were presented. Another important issue in BWRO and SWRO was scaling prediction with emphasis on new methods to predict silica and carbonate scaling. Models were presented to optimise SWRO systems and to predict the performance of BWRO systems. An interesting combination of BWRO in conjunction with aquifer recharge using wastewater was presented. Modelling of electrodialysis systems and their successful application to remove nitrate from brackish ground water in Algeria concluded this session. 
The use of wind, solar, and nuclear energy and water reuse were on the agenda for the afternoon sessions. Results of case studies on the use of solar and to a lesser extent wind energy, to power distillation systems were presented by country representatives from Tunisia, Palestine, Algeria, Portugal, Israel and Bahrain. Very promising results of case studies involving treatment and reuse of water were reported from Tunisia, Kuwait, Spain, Israel, Algeria, France and Syria. A myriad of techniques e.g. RO, MF, UF, ED and NF were evaluated to remove targeted pollutants such as bacteria, viruses, cysts, dissolved salts and suspended matter. In the last technical session of the conference the latest innovations in desalting technology were presented. 
Novel developments involving the use of low cost ambient energy for desalting and the development of systems to store intermittent thermal energy were discussed. Other innovations included the use of thermal desalting and a desalting system based on the use of CO2 . 

The highlight of the conference was without a doubt the extremely lively round table discussion with representatives from different countries of North Africa, Europe and Mr. Rodney Standring of the EU, and active participation of the audience. Discussions brought spontaneous proposals for cooperation and sites for following meetings ó hopefully also to report on practical steps taken in between.
The final item on the agenda of the conference was a session on ëCapacity Building Strategies for Desalination in the Middle East and North Africaí, which was co-ordinated by Klaus Genther (MEDRC) and Hisham El-Dessouky (Kuwait). This session focussed on the need for institutional capacity building programmes in desalination and representatives from 12 countries reported on the various programmes available in their home countries. A detailed report of this session is available in the newsletter of the Middle East Desalination Research Centre (MEDRC) issue 10, September 2000.
The entire proceedings will be published in the Desalination Journal to appear early next year, edited by Miriam Balaban.
As usual no conference would be complete without a few social events. The first of these was held on Tuesday evening when all participants were invited to a Tunisian dinner in a traditional old Tunisian menzel house in Jerba. There was a tour of the menzel by members of the family. The second social event was the conference dinner held in the Royal Garden hotel on Wednesday night. Normally, most people remember a conference dinner by the quality of the food. Despite the fact that the food was great, I expect that most people will only remember the belly dancer (compliments of the hotel) ó in particular the attempts of the senior members of EDS to ëbelly danceí was a sight not to be missed. A beautiful day was had by all with memorable visits to many local sites and of course no conference would be complete without a shopping trip in the colourful souk.

Maria Kennedy, EDS member

Desalination and the Environment 
2001 Cyprus
2003 Malta
2005 To be announced 

Membranes in Drinking and Industrial Water Production
Autumn 2002 Mühlheim, Germany
September 2004 United Kingdom
September 2006 LíAquila, Italy

Membrane Technology for Wastewater
Reclamation and Reuse
9-13 September 2001 Tel Aviv, Israel

The Hashemite Kingdom of Jordan Ministry of Energy and Mineral Resources for Development of 100-300 MW Oil Shale Fired Power Plant on BOO Basis
The Ministry of Energy and Mineral Resources (MEMR) is inviting proposals from interested qualified sponsors with proven capability in power projects development to develop a 100-300 MW oil shale fired power plant using direct combustion technology including fluidized bed technology at Sultani area (South of Jordan) on a Build, Own, and Operate (BOO) basis.
Sponsors are requested to submit a technical and a financial proposal in two separate envelopes. The technical proposal shall include proposal letter, project description, generating capacity, project schedule, annual output of the project in kWhs, financial and commercial terms related to the project, draft implementation, power purchase and oil shale exploitation agreements, and project layout whereas the financial proposal shall contain the sponsors tariff proposal with the exception of government royalty.
The government royalty will be added to the tariff as a supplementary charge. The successful sponsor will be selected after a transparent evaluation process to the received proposals. MEMR will evaluate all proposals based solely on the technical proposal submittal. MEMR will open the financial proposals of only those deemed to be most sttractive.
The selected sponsor will be asked to arrange the necessary financing and to finalize the implementation, power purchase, oil shale utilization and other agreements required for the financing, construction, operation and maintenance of the power plant, establish the project company and upon commissioning, operate the facilities for a certain period of years (to be specified by the sponsor) so as to sell the electricity to the National Electric Power Company (NEPCO) at a specified tariff. The project company shall be established and registered in Jordan in accordance with the applicable electricity law and companyís law immediately after the completion of the negotiation of the agreements.
MEMR and the Natural Resources Authority (NRA) will make available all information and data related to oil shale at Sultani srea and the Jordanian power system to all interested parties. You are welcome to conduct studies, collect samples of oil shale and carry out drilling activities, etc. in coordination with NRA.

All inquires pertaining to the oil shale information and studies shall be directed to:
Director General of NRA at:
Natural Resources Authority
P.O. Box 7 Amman, Jordan
Tel. +962 6 5857600
Fax +962 6 5811866
Email: nra@amramnic.gov.jo
Your proposal should be submitted to MEMR on 1200 hrs Jordan local time of May 31, 2001 at the following address:
Secretary General
Ministry of Energy and Mineral Resources
P.O. Box 140027 Amman 11814 Jordan
Email: memr@amra.nice.gov.jo

Water Desalination Plant in Sudan
Elnasr Industrial Trading Co. Ltd. Is one of the leading industrial groups in Sudan, operating several factories and in import and export.
We are planning to build a water desalination plant in Port Sudan on the Red Sea together with the local government. The plant is to produce 25,000 m3 of drinking water per day using sea water. Finance is available from the Islamic Development Bank. 
The plant is top priority on the government list owing to the bad water supply in Port Sudan. We are looking for reliable companies who can handle such a project.
For further details contact:
Sayed Elhassan
Jakarta Office Manager
Tel. (021) 428 76081 Fax (021) 428 76080
Email: elnaser@centrin.net.id
Project Proposal
Direct Reverse Osmosis. An Approach to Energy Saving Saline Water Desalination
Deep valley large scale sea or brackish water desalination by using level differences between sealevel and elevated brackish water lakes and inland depression by direct reverse osmosis.
MY-TEC is an engineering office engaged in the design of reverse osmosis plants and in designing improved 
reverse osmosis designs for plant manufacturers.
For further datails:
Dr. Von Mylius Engineering
Tel./Fax +32 637 3607/2064
Email: umyliu@spectraweb.ch

cleaning, antiscalants, energy recovery, pre-treatment and post-treatment options, costs of RO vs. thermal system.
Boiler feed water and ultra-pure water systems. Technical visits to membrane plant.
Location
International Institute for Infrastructural, Hydraulic and Environmental Engineering (IHE) Delft, The Netherlands
Fee
3000 NLG (1 EU is approx. 2.2 NLG)
Course co-ordinators
Prof. Dr. Ir. Jan Schippers and Dr. Maria Kennedy
Tel. +31 15 215 1774 Fax +31 15 212 2921
Email: mdk@ihe.nl Web: www.ihe.nl

Sponsored by
European Desalination Society

Water Shortage, Desalination and the Environment
May 27-31, 2001, Lemesos (Limassol), Cyprus
The conference is sponsored by the European Desalination Society, the International Water Association, the Government of Cyprus, Cyprus Water Development Department, and Lemesos (Limassol) Water Board.
The conference will be devoted to desalination and the environment, and consideration of how desalination could be used as a sustainable source of water. The conference will give an overview of the most recent developments in desalination technology. It will bring together research scientists, engineers, managers and operators from water supply companies, industries, government departments, consulting firms, research institutes and universities. 
The topics will include inter alia how a country will decide to desalinate water, how to integrate desalination and water purification into water resource management, environmental impact of desalination ó brine disposal. BOT, and contract preparation. A session will be held for the public to provide information and answer questions.
Visits
There will be technical visits to desalination plants
Topics include:
- Water scarcity
- Water management
- Environmental considerations
- Scaling and material selection
- Materials and water resources
- Removal of specific compounds
- Wastewater treatment
- Seawater reverse osmosis
- Pretreatment for NF and RO
- Renewable energy and energy saving
- Cogeneration and distillation
- Membrane concentration and brine disposal
- Desalination in remote arid areas
Exhibit
An exhibit will run concurrently with the conference. This will be an ideal opportunity for engineering and service companies, equipment and chemical manufacturers, and consultants to fully introduce themselves to their potential customers.
Please contact: Ursula Annunziata
Fax: +44 1753 712040
Email: uannunziata@permacare.com
For further information on the conference please contact EDS Secretariat

• Newsletter February 2000