Seawater desalination plants attempt to convert seawater into clean water by removing minerals from the seawater. There are two main method of treating seawater. The first is a thermal method and the second is using membranes. The thermal method, which is also known as distillation, separates water and salt through evaporation. Membrane processes pass water through semipermeable membranes under pressure.

The most common methods of treating water are as follows:

(1) Multi-effect Distillation;

(2) Multi-stage Flash;

(3) Vapor Compression;

(4) Membrane Reverse Osmosis;

(5) Electrodialysis;

(6) Reverse osmosis (this is the most commonly used method)