How Reverse Osmosis Works

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1. Basic Idea: Reverse osmosis is like a super fine sieve that only lets water molecules through and blocks everything else. Imagine you have a strainer that can catch even the tiniest particles, but instead of catching food, it catches impurities in water.

2. The Membrane: At the heart of an RO system is a special filter called a semi-permeable membrane. Think of this membrane as a very picky gatekeeper. It has tiny holes that are small enough to let water molecules pass through but too small for most contaminants like salts, bacteria, and chemicals.

3. Applying Pressure: To get the water to go through this picky gatekeeper, we need to push it really hard. This is done using pressure. Imagine trying to squeeze water through a sponge. You need to press down hard to get the water out. In an RO system, a pump applies pressure to the water, forcing it through the membrane.

4. Separation: As the water is pushed through the membrane, clean water (called permeate) passes through to the other side, while the contaminants (called brine or concentrate) are left behind and flushed away. It's like squeezing juice from an orange: the juice comes out, and the pulp stays behind.

5. Multiple Stages: RO systems often have several stages of filtration. Before the water reaches the membrane, it goes through pre-filters to remove larger particles like dirt and chlorine, which could damage the membrane. After passing through the membrane, the water might go through additional filters to polish it up and make sure it's as clean as possible.