Monitoring of ultraviolet light sources for water disinfection

Disinfection of waste and drinking water using ultraviolet (UV) light has become a recognized method of protecting public health as part of a multiple barrier approach. UV provides an ideal method to inactivate harmful pathogens that are resistant to treatment by chlorine, allowing the use of less chlorine so that less chlorinated carcinogenic byproducts are present in drinking water. The most widely accepted UV light sources for disinfection are low and medium pressure mercury arc lamps. The advantages and disadvantages of both light sources for disinfection are highlighted. The challenges of providing sufficient UV dose to compensate for water transmittance quality and the spectral properties of the sensor used to monitor UV light intensity are discussed.