Seawater desalination: Study of three coastal stations in Algiers region

According to recent demographic statistical data, the number of inhabitants in Algeria should double in the next thirty years whereas availability of water resources will not change. The hydrologic situation especially for the coastal areas reflects severe drought conditions that are lasting since two decades. Seawater desalination could be an efficient alternative in order to mitigate the forecasted serious water shortage crisis. In fact, due to rural depopulation a large majority of the people and the economic activities are nowadays concentrated in the coastal cities of the Mediterranean coast along ~1200km. The good physical and chemical features of Mediterranean seawater (19°C and medium salinity as compared to that of Persian Gulf which exhibits 30°C and much higher salinity) make of Mediterranean desalination plants more profitable with less operating costs and better efficiencies. Reverse osmosis has been chosen as the best desalination process because it has seen many technological improvements especially with regard to better performance and longer membranes lifetimes. The present study focuses on three small desalination plants located not far from the capital city of Algeria (Algiers) namely: Palm-beach sea resort, la Fontaine and Bou-Ismaïl. Our main objective was directed towards the evaluation of the cost of the chemical consumables and the overall cost of the desalinated cubic meter of water. The latter was found lower than 0.5 €, which is quite interesting. All in all, the desalination option seems to be a good alternative to deal with the most urgent matters in terms of ensuring durable water allocation in the climatic context prevailing nowadays. Selon les statistiques démographiques, le nombre d'habitants en Algérie va doubler dans les trente années à venir, alors que les ressources hydriques conventionnelles n'auront pas changé. La situation hydrique surtout dans les villes littorales reflète nettement un état de sécheresse, qui dure depuis plus de deux décennies. Le dessalement se présente comme une solution efficace face au sérieux problème de pénuries d'eau. En effet, par le phénomène de la littoralisation, la plus grande partie de la population et des activités économiques se trouvent le long des 1200km de côte. Les conditions tout à fait particulières de la mer méditerranée (eau fraîche à 19°c et salinité moyenne, alors que les eaux du golfe sont à 30°C et très salées) font que les coûts d'exploitation des stations implantées en m