Reverse Osmosis Membrane Elements
Want to know how reverse osmosis water filtration works? Consider the following lesson that’s often taught in middle school science classrooms.
Pretend you’re looking in a cup. Inside, there is a thin piece of waterproof clothing for dividing the cup into two separate, yet equal sections. Call this the semipermeable membrane. Now, imagine filling one half of the cup with salt water and the other half with fresh water.
The water level on the saltwater side will rise as fresh water moves through the membrane toward the salt water, which is highly concentrated. This movement is an attempt by the water to have both sides of the cup contain the same ratio of salt. The water in the cup is finding its equilibrium. This natural process is called osmosis.
Pressure is added to the saltwater side to reverse this natural process and create more fresh water. This is referred to as reverse osmosis. In household applications, common water contaminants act as the salt in this example. That is how reverse osmosis water filtration works in brief.