Today it is clear that microplastics and nanoplastics in drinking water are not a future threat but are becoming a permanent part of the biomass. While the World Health Organization (WHO) and Czech institutions such as the National Institute of Public Health (SZÚ) and the Institute of Hydrodynamics of the Czech Academy of Sciences previously took a cautious tone, the latest toxicological studies confirm the presence of plastic microparticles in practically every part of the body (in blood, the placenta and other organs). An excellent review of the topic is Jaroslav Petr: Microplastics and nanoplastics. Small, ubiquitous, harmful? (in Czech). The question is therefore no longer whether we consume microplastics, but whether we can adapt our home infrastructure to minimise our intake.
A fairly large proportion of microplastics enter the body with water. When looking for a reliable solution, people most often ask two key questions: how to choose a filter for microplastics and nanoplastics, and which filter really retains microplastics and nanoplastics without removing valuable minerals from the water.
Microplastics and nanoplastics in tap water vs. well water: where is the risk higher?
A widespread myth is that groundwater from wells is safely protected from plastic pollution by soil layers. Data from hydrogeological surveys, however, refute this assumption.
Tap water: the price of urban infrastructure
In municipal water networks, most microplastics come from two sources: surface reservoirs (atmospheric deposition and run-off from the landscape) and the distribution system itself. Degradation of plastic pipes (polyethylene, PVC, polypropylene) releases microscopic fragments directly into the flowing water. Water treatment plants can capture up to 90% of particles through coagulation, sedimentation and sand filtration, but submicron particles and nanoplastics (smaller than 1 micrometre) pass into the network unnoticed.
Well water: the risk of vertical migration
For wells, the contamination mechanism is different. Microplastics reach groundwater through:
- agriculture: degradation of agricultural textiles and the use of sewage sludge as fertiliser,
- infiltration of rainwater: rain washes particles from tyres (wear), brake pads and roads into the surrounding soil,
- macropores in the soil: during heavy rain, particles are rapidly transported vertically through the soil profile directly into shallow wells.
Standard tap water analyses test dozens of chemicals, but microplastics are not detected. Given their size, concentration, inertness and transparency, they are very difficult to detect at all. We do know, however, that treatment in waterworks removes roughly 90% of microplastics from the source water. We know almost nothing about nanoplastics. Well owners are worse off – they are fully exposed to micro- and nanoparticles, which also often act as carriers for heavy metals and pathogenic bacteria.
What science says: size limits and health risks
According to data published by the Institute of Hydrodynamics of the Czech Academy of Sciences, Czech water sources commonly contain thousands of particles per litre. The key factor, however, is their size. Most plastics detected are smaller than 10 micrometres (μm).
Why is this alarming? The human body excretes particles larger than 150 μm. Particles below 10 μm, however, can penetrate the intestinal barrier and pass into the lymphatic system. Nanoplastics (below 1 μm) pass freely through cell membranes and cause cellular stress.
The water filter market often offers conventional activated carbon filters or sediment cartridges with a porosity of 5 to 20 μm as a “universal solution”. These systems improve the taste of water and capture coarse impurities, but let through much of the most dangerous fraction of microplastics. Almost all nanoplastics pass through.
How to remove microplastics and nanoplastics from water
To remove microplastics and nanoplastics from water effectively, you need to look at the absolute pore size of the filter medium. There are currently four basic technological approaches on the market:
- Carbon blocks and sediment filters: only partially effective against microplastics (usually capturing most microplastics larger than 50 μm). All nanoplastics pass through. A Canadian scientific study from 2023 (1) even found more microplastics after a household granular carbon filter than at its inlet. A compact carbon block is a better but not an ideal solution.
- Reverse osmosis (RO): can eliminate both microplastics and nanoplastics, but at the cost of complete demineralisation of the water (no magnesium or calcium at all) and a large amount of wastewater (up to 3 litres of waste for every litre of clean water).
- Ultrafiltration: a membrane method with a pore size of about 0.01 μm (i.e. 10 nm) that reliably captures all microplastics. It removes nanoplastics down to 20 nm; for smaller nanoplastics, efficiency decreases. It works as a purely mechanical sieve with an extremely dense network of pores that blocks particles of a defined size but lets dissolved mineral salts (calcium, magnesium) pass completely. Publication on the use of ultrafiltration for microplastics (2).
- Nanomembrane filtration or nanofiltration: with a pore size of about 0.001 μm (i.e. 1 nm), this is the technological peak. It captures 100% of microplastics and nanoplastics down to 2 nm. Again, it works as a sieve with an extremely dense network of pores that blocks particles larger than 2 nm, and partially retains and partially passes dissolved mineral salts (calcium, magnesium) (3). The diameter of the hydrated ions of these metals is 0.8–0.9 nm, so the retention of some of these ions indirectly confirms the stated pore size.
Nanotechnology as the solution: the advantages of H2O nanotec systems
In the light of current scientific knowledge, the most effective solutions are ultrafiltration and nanofiltration, which H2O nanotec offers. The H2O nanotec range is built on advanced membrane technologies that are changing the rules of home water treatment.
Unlike conventional solutions, H2O nanotec does not rely on physical sorption to remove microplastics and nanoplastics, but on a barrier formed by a special membrane. The following table compares ultrafiltration and nanofiltration (both for the membranes used in H2O nanotec units).
| Plastic particle size | PAN ultrafiltration, 10 nm pore | Nanofiltration, effective pore approx. 1 nm |
|---|---|---|
| >1 μm – microplastics | 100% | 100% |
| 100–1,000 nm | 100% | 100% |
| 50 nm | 100% | 100% |
| 20 nm | almost 100% | 100% |
| 10 nm | partially | 100% |
| 2–5 nm | low retention | almost 100% |
| approx. 1 nm | 0% | approx. 60% * |
* This is an estimate derived from the retention of hydrated ions of similar size.
Key benefits of H2O nanotec nanofiltration:
- Particle retention: the nanomembrane structure reliably captures not only microplastics and most nanoplastics, but also bacteria, viruses, cysts and microorganisms without the need for UV disinfection.
- Partial preservation of minerals: unlike reverse osmosis, the H2O nanotec filter is relatively gentle on the natural composition of water. The concentration of calcium and magnesium decreases as water passes through the membrane, but some of it remains.
- High flow rate and low pressure loss: the large specific surface of the membrane ensures minimal resistance while maintaining maximum filtration capacity.
For users dealing with contamination of tap or well water, installing the IMT-NC9 nanofiltration under-sink filter from H2O nanotec is an investment in clean water.
Protection against microplastics and nanoplastics in drinking water is no longer a matter of aesthetics or a subjective feeling of cleanliness, but a necessity. Traditional filtration methods reach their technological limits because they cannot capture submicron particles.
H2O nanotec ultrafiltration and nanofiltration membranes are a rational, scientifically based and environmentally sustainable way to turn both tap and well water into a safe source of drinking water for the whole family.
FAQ – microplastics and nanoplastics in drinking water
How do I remove microplastics and nanoplastics from water?
If you are looking for an effective microplastics and nanoplastics filter, you need to look at the absolute pore size of the filter medium. There are four basic approaches on the market: carbon blocks and sediment filters – only partially effective against microplastics (usually capturing most microplastics larger than 50 μm); reverse osmosis (RO) – removes both microplastics and nanoplastics, but at the cost of complete demineralisation and a large amount of wastewater; ultrafiltration – a membrane with pores of about 0.01 μm (10 nm) reliably captures all microplastics and nanoplastics down to 20 nm; nanofiltration – with pores of about 0.001 μm (1 nm) it captures 100% of microplastics and nanoplastics down to 2 nm.
Microplastics and nanoplastics in tap water or well water: where is the risk higher?
A widespread myth is that groundwater from wells is safely protected from plastic pollution by soil layers. Data from hydrogeological surveys, however, refute this assumption.
What are the main advantages of H2O nanotec nanofiltration?
Particle retention – the nanomembrane reliably captures microplastics and most nanoplastics, as well as bacteria, viruses and cysts, without the need for UV disinfection; partial preservation of minerals – unlike reverse osmosis, part of the calcium and magnesium remains in the water; high flow rate and low pressure loss.
Written by:
RNDr. Jiří Polman CSc., Managing Director
References:
- (1) Cherian A., Liu Z., McKie M.J., Almutharam M., Andrews R.C.: Polymers 2023 15(6) 1331
- (2) Zhang U., Zhad W. et al.: J. Environ. Chem. Eng. (2025) Article 114697
- (3) Severino A., Russo B. et al.: Separation and Purification Technology Vol. 360, Part 3, 131232
