Introduction to Ultraviolet (UV) Water Disinfection Systems

Over 100 years ago, German scientists discovered that the top surface of lake-water was sterile when exposed to sunlight. Investigation led to the discovery of ultraviolet light. Situated in the electromagnetic spectrum between X-rays and visible light, ultraviolet (UV) light has many beneficial properties.

UV light is split into four main categories, UV-A, UV-B, UV-C and Vacuum UV. The area between 240 and 280 nanometres (nm) is UV-C, commonly known as the germicidal region.

Bacteria, viruses and yeast are deactivated by UV-light at a wavelength of 254 nm (the main emission of a Mercury low-pressure lamp). The deactivation rate is a function of the UV-dose this leads to fixing the UV-dose at 400 J/m² for drinking water disinfection, test work has confirmed that this dose showed a reliable reduction of more than 99.99% for the relevant types of microorganisms.

UV disinfection

How Ultraviolet (UV) Water Disinfection Works

UV disinfection reactors have to be able to penetrate water with a minimum dose. The absorption of UV-light in water, the geometry of the irradiation chamber, the residence time in the irradiated area and the residence time distribution of the water are important parameters.

Ultraviolet (UV) light water purification is a physical, non-intrusive method of ensuring that organisms, which are airborne or present in most fluids, are unable to replicate and thus remain inert. Correctly sized UV light water sterilization systems can also be used to de-chlorinate or de-ozonate process water and to assist in the removal of TOC and urea from ultra-pure water.

UV water filtration systems do not affect the taste, colour or pH of the fluid being disinfected and, as such, the technique is often used where conventional chlorine disinfection cannot be applied.

The layout design of UV-reactors is critical when determining flow through UV dosage rates. The residence time in a conventional UV-reactor is always difficult to determine accurately. For this reason an exact calculation of the dose is not possible for conventional UV-reactors and thus a corresponding deactivation rate. This is the reason why Enviolet UV-reactors are designed with a rotational flow with high levels of mixing ensuring that water passing through the reactor has at some point had an optimum dosage rate of 400 J/m².

UV Systems

Belmar Technologies Ultraviolet (UV) Water Disinfection

Belmar Technologies is the exclusive UK distributor for the full range of UV Water Disinfection products designed and manufactured in Germany by Enviolet GmbH.

Working with Enviolet we can supply ultraviolet water treatment systems designed to meet any customer's specific requirements.