UV dose definition

UV dose means the units of intensity of ultra violet light that is required to kill bacteria and viruses present in the effluent;
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UV dose means the UV energy per unit area incident on a surface, typically reported in units of mJ/cm2 or J/m2. The UV dose received by a waterborne microorganism in a reactor vessel accounts for the effects on UV intensity of the absorbance of the water, absorbance of the quartz sleeves, reflection and refraction of light from the water surface and reactor walls, and the germicidal effectiveness of the UV wavelengths transmitted.
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Examples of UV dose in a sentence

  • UV dose is the amount of UV energy per unit area that falls on a surface.

  • Table 4-7 Recommended UV dose for the inactivation of microbes (mJ/cm2; EPA, 2011) Target Log Inactivation Giardia cysts1 1.5 2.1 3.0 5.2 7.7 11 15 22 Cryptosporidium oocysts1 1.6 2.5 3.9 5.8 8.5 12 15 22 “Viruses”1 39 58 79 100 121 143 163 186 Adenovirus type 402 56 111 167 Poliovirus2 7 15 22 30 B.

  • The reactor operation is fully automatic and controlled to maintain required UV dose for the flow rate and water quality conditions as described above.

  • In air and surface disinfection applications UV effectiveness is estimated by calculating the UV dose which will be delivered to the microbial population.

  • The UV dose is calculated as follows: where D is UV dose Ws/cm², I is UV intensity W/cm² and t is exposure time (seconds) For a linear lamp, the UV intensity is inversely proportional to the radial distance from the lamp.

  • To ensure proper inactivation of pathogens, an effective UV dose needs to be calculated based on UVT, UV light intensity and flow rate (exposure time).