Measuring and controlling UV and ozone – safe and efficient

Wapure International stands for 35 years of experience in research and development of water purification

Deactivation of a chlorine-resistant bacterium using the UVOX method

systems with ultraviolet irradiation, ozone oxidation and advanced oxidation. The main objective of Wapure is to push ahead with environmentally friendly, safe and healthy water purification equipment and making this technology available for smaller budgets. Wapure International attaches particular importance to the quality and performance assurance of its systems. The UVOX-Redox measurement and control systems therefore have absolute priority.

UV-Disinfection: the minimum UV Dosage in order to guarantee a 99,9 % killing rate of all pathogens.

UV-Disinfection: the minimum UV Dosage in order to guarantee a 99,9 % killing rate of all pathogens.

• Lamp output in UV Light (254 and 185 nm)
• the layer density
• the dwell time of the cells in the ultraviolet light, which results again from the flow rate.

This minimum ultraviolet irradiation dosage leads to a killing-offrate of 99,9% of all pathogens, like bacteria, viruses and algae, when passing through the UVOX-System once.

The optimal dosage of ozone and the advanced oxidation process (AOP):

The needed amount of ozone depends on various factors and therefore differs to a large extent. A redox measurement gives insight in the actual oxidation power of ozone (and therefore its concentration) at time of measurement. The concentration of ozone is determined by the increase in redox potential as result of the injection of the ozone. In case there is sufficient dissolved ozone left in the water, when passing through the UVOX reaction chamber, the Advaned Oxidation Process (AOP) will automatically be accomplished in order to reduce various persistent compounds.

In order to measure the effectiveness of the Advanced Oxidation Process, a two point redox measurement will be made in order to adjust the sucking in performance of the UVOX injection system.

Selection of the right UVOX-System

A pre-requiste for the UVOX System is a defined UV irradiation dose rate measured in mJ/cm² at the end of the service life of the UVOX Lamp.

This minimum UV-Intensity is a function of:

  • lamp efficiency (Lamp Output in UV-C)
  • retention or dwell time of the cells exposed to UV-C light, which results in the flow rate through reaction chamber
  • the UV-Transmission through the fluid, which is determined by the layer density and the clouding of the water.

Depending upon the application UVOX guarantees a certain minimum UV- Intensity (in mJ/ cm²):


Control by measurements

The UV-Compact measures the UV intensity of the water, the water temperature and the internal temperature of the UVOX system. This ensures the proper functioning of the UVOX.

A redox measurement provides information about the currently existing oxidation power of the water. The increase of the redox potential due to the ozone supply is informative. For some process water applications, the UVOX Redox Pilot therefore measures the redox potential in two places: once before and once after the ozone injection. This allows an optimal and stepless adjustment of the ozone supply for the best possible result.

As result of this you can select your UVOX System:
UV-Transmission at t=10 / 90%