Treatment process
Aeration
Bringing water into contact with air. A simple, low-energy step that oxidises iron and manganese, strips volatile compounds and dissolved gases, and raises pH by removing carbon dioxide.
Key facts
- Scale
- Municipal and household
- Treatment stage
- Pre-treatment
How it works
Cascades, spray aerators, packed towers or diffused air. Volatile compounds transfer from water to air along their concentration gradient; dissolved oxygen transfers the other way.
What it removes — and what it does not
| Row | Removes | Does not remove |
|---|---|---|
| 1 | Dissolved carbon dioxide, raising pH | Non-volatile dissolved substances: salts, nitrate, metals in solution, PFAS |
| 2 | Hydrogen sulphide and its odour | — |
| 3 | Volatile organic compounds including solvents | — |
| 4 | Radon | — |
| 5 | Oxidises dissolved iron and manganese so they can be filtered out | — |
Trade-offs
- Very low energy and chemical demand
- Transfers volatile contaminants to air, which may itself require control
- Large footprint for packed tower designs
Related intelligence
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Sources
- World Health Organization — Guidelines for Drinking-water Quality. Public but restricted · CC BY-NC-SA 3.0 IGO
- NSF International / American National Standards Institute — NSF/ANSI drinking water treatment unit standards. Public but restricted · Publisher terms — public access, reuse not clearly granted
- American Water Works Association — AWWA standards, water audits and utility benchmarking. Public but restricted · Publisher terms — public access, reuse not clearly granted