Conventional treatment — coagulation, filtration, disinfection — was designed to remove particles and micro-organisms. It does that job very well. It was not, however, conceived to retain dissolved molecules present at trace level.
What gets through
- Residues of pharmaceuticals and personal care products.
- Certain pesticides and their metabolites.
- PFAS and other persistent fluorinated compounds.
- Disinfection by-products formed during chlorination.
The advanced processes
Granular activated carbon adsorbs a wide range of organic molecules. Nanofiltration and reverse osmosis separate them physically. Advanced oxidation processes break them down chemically. Each has its own field of effectiveness — none of them treats everything.
Why this matters for health
The concentrations involved are low, but exposure is daily and lasts a lifetime. The principle adopted by health authorities is to reduce exposure wherever a process exists and remains proportionate.
Sensitive applications first
Healthcare facilities, food processing, laboratories, hospitality: these are the settings where an advanced treatment stage is justified first, because the water comes into direct contact with patients, products or critical processes.