Supercritical UV™ Disinfection of Viruses in Wastewater
Viruses in wastewater can pose significant risks to human health if not appropriately treated before being released into the environment. The effectiveness of a UV disinfection system to deactivate a virus depends on the virus type. This effectiveness is typically measured by the UV dose, where the higher the UV dose the more difficult the virus is to treat. For example, as shown in the graphic, influenza requires a low UV dose and is relatively easy to disinfect, while adenovirus requires a much higher dose and is harder to disinfect.
*There are many variants for each virus with varying degrees of treatability. While this diagram is based on literature dose rates, it should only be understood as a generalisation for illustrative purposes. For specific concerns or applications please talk to our team.
Due to its difficulty to treat and ability to be cultured in the laboratory, bacteriophages are routinely used in wastewater effluents as a viral indicator organism. As such, bacteriophage has been used to demonstrate the viral disinfection capability of Novolabs™ Supercritical UV™ technology.
Case Study 8A:
A large multi-pond waste stabilisation system exhibited the following wastewater characteristics: a UV transmittance (UVT) of 47.8%, total suspended solids (TSS) of 12.8 g/m3, and a bacteriophage concentration before UV averaging 1,061 pfu/L.
After Supercritical UV™ disinfection, only 1 sample had a detectable bacteriophage concentration of just 16 pfu/L. Novolabs™ Supercritical UV™ system reduced the bacteriophage concentration in every other sample to below the detection limit of 10 pfu/L.
Case Study 8B:
A single waste stabilisation pond with a dividing baffle had the following wastewater characteristics: a UVT of 54%, TSS of 4 g/m3, and a bacteriophage concentration before UV averaging 53,600 pfu/L.
Bacteriophage was reduced by an average of 3 log across all UV doses tested. The highest bacteriophage concentration after Supercritical UV™ disinfection was 340 pfu/L which occurred when the inlet concentration reached a peak of 140,000 pfu/L. At the Supercritical UV™ system's highest UV dose, every single bacteriophage sample was reduced to below the detection limit of 10 pfu/L in all 5 days of testing.
