In order to define the optimum size of the UV reactor, suitable to your needs, we need information regarding the water quality, which is determined by Ultraviolet Transmittance (UVT), the distance between the lamp and the reactor wall, the distribution of UV light and hydraulic characteristics. UVT is the most critical parameter and represents the required UV light intensity to penetrate a fluid. Thus, if the water is of high quality, e.g. borehole water, the UVT will be high – around 95% UVT, while a low quality water, e.g. river water, will have a low UVT – around 80% UVT. It should be mentioned that a slight decrease in UVT% alters the amount of UV intensity required to provide disinfection. Turbidity and natural organic matter (NOM) affect the UVT significantly.
The UV dose is measured as energy per unit area (e.g. mJ/cm2) and is the product of UV intensity (mW/cm2) and contact time (s) within the UV reactor of the treatment system. The UV intensity is a function of lamp features (type and power), while the contact time depends on the volumetric flow rate of the water and the geometry of the UV chamber.
The criteria that ensure the selection of an appropriate UV system suited to your needs are:
- Water ﬂow rate
- Type of lamps
- UV dose
- Type of microorganisms to be deactivated
- Rate of disinfection
- Water temperature
Water ApS offers significant benefits over competitive systems. Many of the benefits are unique due to the design of UV system, which creates the most efficient UV reaction chamber and delivers a constant UV dose with fewer UV lamps, meaning that the required energy, the total cost – including operation costs and maintenance, are limited to minimum and therefore, it results in an incomparable UV performance. Depending on the water characteristics UV systems are equipped either with low or medium pressure lamp.