Original story

CompuMedia 31.10.2004

Desalination plants bring life to Northern Sahara

The supply of fresh water has brough lush vegetation to formerly desert areas on the southern shores of the Mediterranean. The first desalination pools have been in operation in Northern Morocco for around a year, and results are encouraging. Experts expect the project, which was funded by the World Bank, could have far-reaching effects in the global battle against hunger.

Forget the image you have of the coast of Morocco. Things look very different there now from just one year ago. Admittedly, the vegetation is not very high yet, but the familar sand-dunes now have a good covering of green. In the early stages of the “Greening the Desert” project the accent has been on introducing plants with deep roots that are adapted for living in damp sand. In the next phase - after the sand has been bound together - the number and range of plants will be nicreased gradually. The project will have achieved its stated aims in around ten years, by which time plants will have died off and decomposed to form a thin but viable layer of humus. Mohammed Bin Assam, the site manager for the project, was entusiastic about the first year’s progress, saying that people now have a belief in the future and that the project staff are treated like royalty by the locals.

What has made the change possible is the construction of 20 massive desalination pools. Each is approximately 4 kilometres long and 80 metres wide. The pools are fitted with anodes and cathodes, which slowly separate out the salt from the water. The process takes place in two stages. In the first pool the salinity of the water is reduced from around 6500ppm to roughly 500ppm, and in the second it becomes potable fresh water.

Since the energy resources available are limited, the process is a slow one - a pool of freshwater can be extracted in 12 days. Solar panels and wind generators are adequate to provide the necessary electrical charges for the process. In contrast to previous similar desalination projects, the Moroccan experiment is relatively cheap, since in addition to the obvious capital investment and maintenance costs, the largest single expense item is transport of the salt away from the pools. This problem is already being addressed through the development of a form of algae that has been gene-manipulated such that it breaks down common salt into its component parts of sodium and chlorine. The latter it uses for anaerobic assimilation, and thus it produces energy through the chlorine. This energy can then be fed back into the system to support the energy needs of the pools themselves. The original strain of algae was derived from a saline lake in the United States.

One months ago the World Bank announced that it would be funding other greening projects to be launched in Eritrea, Ethiopia, and Yemen.

Toteuma-arvio 2026

Toteuma lyhyesti

  • Ilmiön toteuma: 3/5
  • Toteuma viiden vuoden tarkkuudella: kyllä; arviointi-ikkuna on 1999–2009
  • Toteuma väljemmällä aikahorisontilla: kyllä, mutta rajatusti
  • Ilmiön ydin: meriveden suolanpoisto mahdollistaa asutusta ja viljelyä kuivilla alueilla.

Suolanpoistosta tuli tärkeä vesihuollon lähde Lähi-idässä ja Pohjois-Afrikassa, ja vettä käytetään myös maatalouteen. Laajaa Saharan viherryttämistä menetelmä ei ole saanut aikaan, sillä energia, kustannukset ja suolaliuos rajoittavat käyttöä.

Johtopäätös: ydin toteutui osittain, mutta ennakoitu ympäristövaikutus jäi paljon pienemmäksi.