A reverse osmosis (RO) water filter works by forcing water through a semi-permeable membrane under pressure to remove impurities, providing you with cleaner, purer water.
Here's a breakdown of the process:
1. Pre-Filtration: Protecting the Membrane
The incoming water initially passes through one or more pre-filters. These filters typically remove sediment, chlorine, and other larger particles. This pre-filtration stage is crucial because it protects the delicate reverse osmosis membrane from damage and clogging, extending its lifespan.
2. Reverse Osmosis Membrane: The Heart of the System
This is where the magic happens. The pre-filtered water is forced through the semi-permeable reverse osmosis membrane. This membrane has tiny pores that allow water molecules to pass through, but block contaminants like:
- Dissolved salts (sodium, chloride, etc.)
- Heavy metals (lead, mercury, etc.)
- Minerals
- Microorganisms (bacteria, viruses, etc.)
The contaminants are flushed away, while the purified water proceeds to the next stage.
3. Post-Filtration (Optional but Common): Enhancing Taste
After passing through the RO membrane, the water may go through a post-filter, often a carbon filter. This final filtration step polishes the water by removing any remaining tastes or odors, resulting in improved flavor.
4. Storage Tank: Ready When You Are
Because the reverse osmosis process is relatively slow, the purified water is typically stored in a holding tank. This tank is usually located under the sink, providing you with a readily available supply of clean water.
5. Dedicated Faucet: Dispensing Pure Water
Finally, the purified water is dispensed through a separate, dedicated faucet installed on your sink. This prevents the purified water from mixing with unfiltered water from your main faucet.
Summary of the RO Process in a Table
| Stage | Function | Impurities Removed |
|---|---|---|
| Pre-filtration | Removes sediment and chlorine | Sediment, rust, chlorine |
| RO Membrane | Removes dissolved solids and contaminants | Salts, heavy metals, minerals, microorganisms |
| Post-filtration | Improves taste and odor | Residual tastes and odors |
| Storage Tank | Stores purified water | N/A |
| Dedicated Faucet | Dispenses purified water | N/A |
Reverse osmosis systems are typically installed under the sink and connected to the main water supply. They are highly effective at removing a wide range of contaminants, providing clean and great-tasting water for drinking and cooking.
