IELTS Task1 - Describe process: How salt is removed from sea water to make it drinkable

 

In recent years drinkable water made by seawater is an increasing popular drink in the human life. However, there is a few people know the production of it. This essay will describe how the purified water is produced.

There are several stage involved in the purified water production. In the first step, saltwater from the sea is intaken to the pretreatment filter where the debris is removed and the backwash is sent back to the sea. After that, the filtered water forced though membrane at high pressure with the purpose of purifying the seawater. At this stage, the water is filtered by a water molecules to separate salt and impurities which is returned to the sea after concentrating. Afterwards, the chemical stage requires post treatment with lime, chlorine and fluoride at the same time. In the final step, the purified water is stored in a storage before integrating water supply system.