Validation & certification

Good in theory

When the biological quality of liquids or surfaces is important for your organisation, a UV disinfection system is an essential link in the chain. However, it is not automatically true that all UV systems are disinfecting well. Many producers calculate the effectiveness of their system based on theory. The intensity of the lamp is multiplied with the to be treated volume and the flow (the amount of liquid passing through), the number derived from this is the average UV dose. But an average dose does not mean very much. This is due to the fact that part of the liquid is above average and part of it is below average. One part of the stream gets too little UV (which means the micro organisms simply survive) and part of the stream gets too much UV (which gives the micro organisms a lethal dose ten times over, when just once is enough). Good in theory doesn’t translate to good in practice.

Good in practice: validation

We want to produce systems that are high quality both in theory and in practice. As such, all reactors in the Van Remmen UV Technology Validated and Certified series are tested in a standardised practice situation. We measure the actual biological breakdown. That way you can be sure that every UV-reactor gets the biological killing off level and UV dosage it is meant to get. That way, not a single aspect is dependent on theoretical calculations based on assumptions. You have the assurance and hard guarantees and a process that uses UV light efficiently.

Standards and certification

Our systems are produced and certified according to European standards.
As such, we work according to NEN EN 14897:2006+A1. This is identical to CEN, the European standard. This standard has been assigned to Van Remmen UV Technology, licensed by NEN.
But what does this mean exactly?
The standard makes a distinction between water treatment and disinfection. Due to this there are two levels of validation:

• For water treatment, it is based on the system’s technical abilities. In other words: the abilities are not guaranteed, but under standard conditions, you can safely assume that the system works for the goal in mind.
• Disinfection: treatment capabilities are properly tested according to the NEN standards and can be guaranteed.

Sterilisation

Disinfection is often confused with sterilisation. There are some important differences. With sterilisation, micro organisms are completely removed from liquid. No micro organism survives a proper sterilisation. Disinfection removes the danger of infection and harmful micro organisms are not completely deactivated or reduced.

Why would you choose disinfection instead of sterilisation? Sterilisation is a drastic and expensive method. High temperatures, chemicals, and intensive radiation are used. Disinfection is preferable for many purposes. This removes the danger of infection. That is usually enough. Generally, sterilisation is only used when even the smallest risks have to be avoided at all costs.

How does validation work?

We test our Validated and Certified series with biodosimetric tests. With this, a predetermined amount of bacteria traces (bacillus subtillus, ATCC 6633) is added to the entering water stream before the UV reactor. These traces have very consistent UV sensitivity, are easy to grow, and are harmless to humans and the environment.

By measuring how many bacteria traces enter the UV reactor and how many come out alive one can determine the exact level of removal. The applied UV-C dosage in the validation tests is 400 – 600 J/m² but always higher than 400 J/m². Van Remmen UV-reactors are always validated at a minimum reduction of 99.9% of Bacillus subtillus. Usually we reach a removal level that is much higher, this can run up to 99.999%.

For the validation process we also vary the light transmittance of the liquids and we use a varied UV output from the lamp itself. From that we can also tell when the lamp is at the end of its lifespan and needs replacing. Up to the end of the listed lifespan, the system will meet the requirements of the determined UV dosage and determined reduction requirement.
The values from the validation test can be calculated into a UV-Dosage according to the latest European norm (NEN-14897).

The two graphs below detail what validation provides:

Operation of a competing UV system with calculated UV-C dosage, which is noticeably higher than the actual dosage after validation. Such a reactor would provide (close to) no disinfection results.

Abilities of Van Remmen UV system with a theoretical capability that is lower than the actual capability. Higher efficiency that translates in lower investments, less energy use, less maintenance, while keeping a high level of disinfection.