National Education Lesson

I used to think that Singapore obtains their NEWater by mostly using the distillation and evaporation methods. But now I think that NEWater is obtained mostly by using the reverse osmosis method.

At first, I also used to think that reverse osmosis is not a method to separate mixtures. But now I think that when using reverse osmosis method, sea water is pre-treated to remove insoluble substances like debris and contaminants such as oil, grease and suspended solids. The sea water which has been pre-treated will then be pumped at high pressure into the partially-permeable membranes to remove all traces of soluble substances. [Soluble substances: Bacteria, chemicals, dissolved minerals, etc.]

I used to think that both reverse osmosis and desalination are the same method. But now I think that they are different as reverse osmosis is a type of method mostly used for desalination.