No single technology is optimal for every water. Selection requires a comparison of treated water quality, investment, operating costs, consumables, waste, maintenance and reliability.
Qualitative comparison
- Reverse osmosis
- High salt separation capability; requires investment, energy and concentrate management.
- Nanofiltration
- A membrane-based alternative with design-dependent selectivity; residual fluoride must be verified.
- Adsorption
- A potentially compact solution; saturation, regeneration or replacement must be managed.
- Ion exchange
- Dependent on selectivity, competing anions and regeneration.
- Electrodialysis / EDR
- Useful for certain brackish waters; fluoride separation and electricity costs must be assessed.
- Electrocoagulation
- Electrodes, energy and sludge must be assessed.
- Coagulation-flocculation-filtration
- Potential to use existing infrastructure; requires optimisation and solids management.
How to compare costs
The appropriate metric is the total cost per cubic metre of compliant water, including amortised investment, financing, energy, chemicals, maintenance, staffing, replacements and waste. Comparing only the purchase price or removal percentage can lead to poor decisions.
Where PayPerLiter fits
It may be particularly relevant when fluoride is the priority parameter, usable infrastructure is available or CAPEX prevents action. The final selection requires an assessment of the actual water and contractual obligations.