By Swati Misra
The Middle East nations started practicing the process of desalination in a fight against water scarcity ages ago, and today, they have become the pioneer in this technology. Most of the oil rich countries like Yemen, Israel, Qatar, Saudi Arabia access sanitary water due to the process of desalination. Recently, Dubai launched UAE’s largest desalination plant in Jebel Ali. So, what exactly is this technology and why has it gained this prominence?
In a desalination plant, the process of desalination can be done in three possible ways, namely, thermal, electrical and pressure-based. These methods are usually based on certain factors like cost, available resources, energy consumption and on the type of water they can be applied on, i.e., sea water or brackish water. Middle East nations consist of the largest number of thermal plants. The process of separating pure water from salt water by distillation is used in the thermal process while using membranes to separate them is followed in the process of RO technology, i.e., Reverse Osmosis. The Thermal process involves two major technologies. They are Multi Stage Flash Distillation (MSF) and Multiple Effect Distillation (MED).
In case of a plant using MSF technology, the sea water is first heated and pressurized and then it is introduced in different cells maintained in low pressure and temperature where the feed water converts into steam. The steam is then condensed into pure water. The final product of the heated water is then reheated multiple times while the pressure keeps on reducing in every new cell. The major disadvantage in this process is that it requires more intake of salt water.
In case of Multiple Effect Distillation, the entire process remains similar to MSF desalination, however, here, the plants do not require a large flow of sea water or brine, thereby, reducing the consumption of electricity.
This process of desalination has been badly criticized for over-using energy resources with a heavy carbon footprint. One of the major disadvantages of this process is its impact on the environment, specifically on the ocean ecosystem. In this process, a huge amount of salt is discharged into the ocean which holds a huge risk of completely destroying the underwater ecosystem.
However, with technological advancements, the process of desalination has become cheaper, cleaner and more energy efficient. In fact the environmentalists of the region believe that the process of desalination have emerged as a substitute to the alternative ways of water management that have become the victims of industrial pollution.