Purified water undergoes several processes to remove impurities and contaminants, and different methods are used to achieve this. While distilled water used to be the most common form, many modern techniques are now employed.
Methods of Purifying Water
Here's a breakdown of how water is purified:
Modern Purification Processes
- Capacitive Deionization: This method uses electrodes to attract and remove ions from the water, effectively reducing salts and other charged impurities.
- Reverse Osmosis: This process uses pressure to force water through a semipermeable membrane, filtering out contaminants, such as minerals, salts, and bacteria.
- Carbon Filtering: Carbon filters use activated carbon to absorb and remove chlorine, volatile organic compounds, and other impurities that affect taste and odor.
- Microfiltration: This process employs fine filters to remove very small particles, like bacteria and some sediments.
- Ultrafiltration: Using even finer filters, this technique removes viruses and other very small particles.
- Ultraviolet (UV) Oxidation: UV light is used to disinfect water by destroying the DNA of microorganisms.
- Electrodeionization: This process combines ion exchange resins and electricity to remove ions, producing highly purified water.
Formerly Common Method
- Distillation: This method involves boiling water and then collecting the condensed steam. It removes many impurities, including salts and minerals, but is more energy-intensive compared to modern methods.
Summary Table
| Purification Method | What It Removes | How It Works |
|---|---|---|
| Capacitive Deionization | Ions, salts | Uses electrodes to attract and remove ions from the water |
| Reverse Osmosis | Minerals, salts, bacteria, and other contaminants | Forces water through a membrane under pressure |
| Carbon Filtering | Chlorine, organic compounds, taste, and odor | Absorbs impurities with activated carbon |
| Microfiltration | Bacteria, some sediments | Uses fine filters to remove small particles |
| Ultrafiltration | Viruses and very small particles | Uses very fine filters to remove very small particles |
| Ultraviolet Oxidation | Microorganisms | Uses UV light to destroy the DNA of microorganisms |
| Electrodeionization | Ions | Combines ion exchange resins and electricity to remove ions |
| Distillation | Salts, minerals, many impurities | Boils water and collects the condensed steam |
By employing one or a combination of these techniques, purified water is produced by removing a wide range of contaminants, from large particles to microscopic ions.
