Comparison of Environmental Impact of Seawater Desalination Between MSF and RO Methods A Literature Review

]n this project a literature review was conducted to consider the latest process developments and operation of seawater desalination plants and their pollution potential, at a global level. Thermal desalination (MSF and MED), membrane separation (RO) and Chemical approaches were pointed out as three main desalination technologies. Two of the more advanced of such operations namely Reverse Osmosis (RO) and Multi-Stage Flash Desalination (MSF) were selected and were compared and contrasted. Then, their advantages and disadvantages were analyzed and finally some recommendations were made to improve the operations and to reduce the pollution potential of such operations. Besides the main Seawater desalination technologies that are currently applied for mega-scale water production in Middle East were found as Reverse Osmosis (RO), Multi-Stage Flash (MSF) and Multi-Effect Desalination (MED). Regarding advantages and disadvantages of the compared methods, RO plants demonstrated some positive and negative differences than the thermal plants such as lower overall energy consumption resulting in less atmospheric emission, higher concentration of the brine, lower increase in the temperature and etc. In general, it was found that with the development of today’s technology, RO desalination has less environmental impacts than thermal desalination because of the possibility of using renewable energies in RO. Although thermal desalination plants have a great potential for reducing environmental effects, if integrated with other production process, both of the methods have their own advantage and disadvantages which should not be ignored. To mitigate the environmental impacts of desalination, different methods were suggested in this thesis such as using a combination of varying decoy screens and a low velocity intake, pre-dilution of reject water with other reject streams, new technologies such as hybrid systems, using renewable energies and etc. amongst them, using renewable energies, as explained in the body of the thesis, seems to be the most efficient solution regarding environmental impacts mitigation.