UV lamps do utilize mercury to generate germicidal ultraviolet radiation. But UV mercury lamps can be safe or dangerous.
A UV recirculator (also known as a closed irradiator) is a device intended to disinfect indoor air in occupied rooms.
UV dose is the main process parameter to evaluate the effectiveness of UV equipment.
Each microorganism requires a specific UV dose due to their individual sensitivity to UV radiation. For a different disinfection level (disinfection efficiency), different UV doses are required. To achieve the higher disinfection level you need to deliver a higher UV dose.
Ultraviolet technology for water, air and surface disinfection is based on germicidal effect of UV-C radiation.
UV radiation is electromagnetic radiation between x-rays and visible light. UV wavelengths range from 100 to 400 nanometer.Within the UV spectrum, UV-C range is considered the strongest UV radiation, which is easily absorbed by DNA, RNA and proteins. This range is often called germicidal due to its high disinfection efficiency against bacteria and viruses. The highest germicidal effect occurs at 205-280 nm and the maximum germicidal sensitivity of microorganisms at 265 nm.
The major advantages of this technology:
Main industrial available sources of UV radiation are low pressure amalgam lamps and mercury medium pressure lamps. Medium pressure lamp technology have higher power per lamp (several kW) but significant lower efficiency (9-12%) in comparison to low pressure lamp technology with efficiencies between of 35-40% and power per lamp up to 1000 watt.