Aluminium is a naturally occurring element that can enter water supplies through soil erosion, industrial discharge, or even water treatment processes themselves. While small amounts are generally not harmful, elevated levels can pose health risks and affect water taste and clarity. This blog explores the most effective methods for removing aluminium from water, highlighting their advantages and limitations to help you choose the right solution.
1. Reverse Osmosis (RO)
How it works:
RO systems use a semipermeable membrane to remove dissolved solids, including aluminium, by forcing water through under pressure.
Advantages:
- Removes up to 97% of aluminium
- Also effective against a wide range of other contaminants (e.g., nitrates, lead, arsenic)
- Ideal for both residential and commercial use
Limitations:
- Requires high water pressure and electricity
- Produces wastewater (typically 3:1 ratio)
- May require remineralisation to improve taste and pH balance
Best for:
Private water supplies with multiple contaminants or where aluminium levels are significantly above safe limits.
2. Ion Exchange (Anion Exchange)
How it works:
Anion exchange resins replace aluminium ions in water with less harmful ions like chloride.
Advantages:
- Can remove up to 99% of aluminium
- Highly effective for targeted removal
- Works well in low-flow systems
Limitations:
- Unfortunately, salt regeneration cannot easily remove accumulated aluminium from the resin. Acid treatment is the best method for regenerating the resin.
- The acid regeneration process makes this method less suitable for residential use
- Sensitive to water pH and competing ions
Best for:
Industrial or commercial systems where acid regeneration can be safely managed.
3. Water Softeners (Low Fouling Resin)
How it works:
Softening systems exchange calcium and magnesium ions with sodium or potassium, and can also reduce aluminium under certain conditions.
Advantages:
- Dual benefit: softens water and reduces aluminium
- Simple to install and maintain
- Compatible with other filtration systems
Limitations:
- Only effective at lower pH levels
- Not suitable as a standalone solution for high aluminium concentrations
- Requires salt for regeneration
Best for:
Moderate aluminium levels in soft water applications, especially where iron is also present.
4. Activated Carbon
How it works:
Carbon filters adsorb contaminants onto their surface. However, aluminium removal is limited.
Advantages:
- Improves taste and odour
- Removes chlorine and organic compounds
Limitations:
- Only removes ~30% of aluminium
- Requires long contact time (up to 6 hours for 60% removal)
- Not suitable as a primary aluminium treatment
Best for:
Supplementary filtration after primary aluminium removal methods.
Choosing the Right Method
The best method depends on your water source, aluminium concentration, and system design. For example:
- High aluminium + high pH: Reverse osmosis is most reliable.
- Low pH + moderate aluminium: Water softeners or ion exchange may suffice.
If you're unsure, a professional water analysis is essential. At GAPS Water Treatment, we regularly advise clients on tailored solutions based on lab results and site-specific needs.