Water desalination and challenges: The Middle East perspective: a review

The Gulf countries are located in the arid and semi-arid regions where rainfall is scanty and evaporation rates are high. Surface water is limited and there are no perennial streams. The increase in population and socio-economic development has led to an imbalance between supply and demand. These countries depend mainly on desalination to meet the growing water needs. This paper reviews the history of desalination and the desalination processes used-multistage flash distillation (MSF), reverse osmosis (RO), multieffect distillation and electrodialysis. An overview of these processes and the challenges faced-like scaling of tubes in MSF and membrane fouling in RO-is discussed. This review also highlights the present trends in water pre-treatment and integrated membrane systems. The depletion of fossil fuels makes it imperative to consider alternate energy sources like solar and nuclear energy. Future prospects for integrated desalination techniques which could result in reduction of cost of desalinated water are outlined. The paper mainly focuses on RO and MSF as these are the most popular commercial processes used in the Gulf region.