What is PFAS?
Where is PFAS?
Test PFAS in water, soil, eggs…
Natural Solutions
Hemp Plant vs PFOS
Pro’s
Con’s
Water Filtration
1. Activated Carbon Filtration (GAC - Granular Activated Carbon)
How it works: PFAS molecules adsorb onto the surface of activated carbon particles.
Pro’s
- Effective for long-chain PFAS (like PFOA, PFOS).
- Widely available and relatively low-cost.
- Suitable for point-of-use (e.g., under-sink) and large-scale municipal systems.
Con’s
- Less effective for short-chain PFAS.
- Requires regular replacement to remain effective.
- Disposal of used carbon can be problematic (contains concentrated PFAS).
2. Ion Exchange Resins
How it works: PFAS are removed by swapping places with other ions on a synthetic resin.
Pro’s
- Highly effective for both long- and short-chain PFAS.
- Longer lifespan than activated carbon.
- Faster treatment rates.
Con’s
- Higher initial cost than carbon filters.
- Requires professional maintenance and disposal.
- Resins must be tailored to specific PFAS types.
3. Reverse Osmosis (RO)
How it works: Water is forced through a semi-permeable membrane that blocks PFAS.
Pro’s
- Removes a wide range of contaminants, including PFAS.
- Effective for both long- and short-chain PFAS.
- Ideal for home use (under-sink systems).
Con’s
- High water waste (can waste 3–4 liters per liter of filtered water).
- Slower flow rate.
- More expensive and requires regular maintenance.
- Also removes healthy minerals (can be re-added)
4. Nanofiltration
How it works: Similar to RO but slightly larger pore size, allowing smaller molecules to pass.
Pro’s
- Good at removing larger PFAS molecules.
- Lower pressure requirements than RO (less energy use).
Con’s
- Less effective for short-chain PFAS.
- Still produces wastewater.
- Higher cost than other methods.
5. Advanced Oxidation Processes (AOPs)
How it works: Uses strong oxidants (e.g., ozone, hydrogen peroxide, UV) to break PFAS bonds.
Pro’s
- Can destroy PFAS rather than just capture them.
- Potential for complete degradation with optimization.
Con’s
- Not yet consistently effective across all PFAS types.
- Complex, energy-intensive, and expensive.
- Still under development for large-scale drinking water use.
6. Electrochemical Oxidation / Plasma Treatment
How it works: Uses electricity or plasma to break PFAS molecules apart.
- Capable of destroying PFAS.
- Promising results in lab and pilot tests.
- Not yet widely available.
- Expensive and energy-intensive.
- Often used in combination with other treatments.
Nomad City Application
At Nomad City we are currently using a Berkey waterfilter to filter our rainwater so we can use it as drinkwater. We use two filters in the Big Berkey system (8,5 liter). We refill the system about four times a week, which adds up to 34 liters a week and 1768 liters a year. This means that each filter is processing about 884 liters a year.
Berkey claims there filters can process 3000 Gallon (VS) = 11356,2354 Liter before they need to be replaced (
). But how frequently the filters need to be replaced also depends on how much water passes through the filters, as well as the contaminant quantity in the water. In their testing Berkey is using laboratory water that is already pretty clean.
Berkey has had some criticism in the past for being overconfident about the performance of their filters. (
). After reading lots of articles and looking at independent test results I found out that their filters are indeed very good but they claim their filters last longer than what they actually tested them for.
According to the stats above we would need to replace our filters every 12 years. But we are not using clean tap water in our system but rainwater which is a little ‘dirtier’ and thus more intense for the system. I am also not 100% convinced that their filters maintain their good performance throughout 3000 gallons. Therefore we decided to replace our filters every three years to be extra sure we have clean drinking water.
These filter systems can also remove healthy minerals from our water. Therefore we added mineral stones in the bottom container of our Big Berkey that are able to re-mineralize the water.
At Nomad City we are constantly researching this topic and looking for improvements.