the way to purify salt water into drinkable

In the era of advance of technology, scientist has found a way to purify the salt water into a drinkable water.  To make it fit to drink, the salt water must be filtered through some steps of purification of salt removal.

First, the impurities water called salt water is sucked into the pipe and go to the pre-treatment filter. In this step there are certain molecules which are removed into the filter backwash.

Second, the water is send to the next purification. In this step water is forced through membrane at high pressure. By the pressure, salt and other impurities will be removed and returned to the sea.

Third, the water comes to the post treatment. This step will purify the water with lime, chlorine and fluoride. Those chemicals are very important to kill the bacteria or viruses before ready to drink.

Fourth, the water will be saved on the storage. This storage is important to control the distribution of water. Finally, the water is ready to be distributed and integrated to the water supply system.