Two effective methods of water disinfection, but with decisive differences. Where chlorine dioxide has the edge over UV disinfection.
Chlorine dioxide and UV disinfection are both effective methods of water treatment, but they have different advantages and fields of application. Unlike UV light, chlorine dioxide continues to work even after the water has long left the treatment system.
Chlorine dioxide and UV disinfection are both effective methods of water treatment, but they have different advantages and fields of application. Where the effect of UV disinfection ends as soon as the water leaves the irradiation chamber, chlorine dioxide develops a lasting protective effect throughout the entire distribution system.
From the residual effect to water quality: this is how chlorine dioxide differs from UV disinfection.
Chlorine dioxide leaves a lasting effect in the treated water.
Unlike UV disinfection, where the disinfecting effect is limited to the water's direct contact with the UV light, chlorine dioxide continues to inactivate micro-organisms even after the water has already left the treatment system. This helps control the growth of bacteria and biofilms in water distribution systems.
Chlorine dioxide is a strong oxidising agent.
It can oxidise and remove unwanted taste and odour compounds in water, such as phenols and hydrogen sulphide, whereas UV disinfection has no such effect on taste and odour compounds.
Chlorine dioxide remains effective even in turbid water.
The effectiveness of UV disinfection can be impaired by water quality, in particular by turbidity and dissolved or suspended solids, which weaken the UV radiation. Chlorine dioxide is less sensitive in this respect and can remain effective even in water with higher turbidity.
Both methods disinfect water reliably. The decisive difference lies in the reach of the effect: UV light works only at a single point in the irradiation chamber, whereas chlorine dioxide works throughout the entire downstream pipe network.
| Criterion | Chlorine dioxide | UV disinfection |
|---|---|---|
| Lasting effect in the distribution system | Yes, residual effect | No, direct contact only |
| Oxidation of taste & odour compounds | Yes (incl. phenols, H₂S) | No |
| Effectiveness in turbid water | Largely independent | Limited by turbidity |
It is precisely this lasting effect that makes chlorine dioxide so strong in everyday use: biofilms, and the germs that settle in them, such as Legionella, form preferentially in drinking water pipes, which is exactly where UV light no longer reaches once past the irradiation chamber. Chlorine dioxide, by contrast, retains its disinfecting effect throughout the entire distribution system.
All statements about efficacy are based on biostream® GmbH's many years of experience as well as information from technical literature, laws, regulations and positive customer references.