Removal of Noroviruses from Municipal Wastewater by Foam Separation using Dispersed Air-Bubbles and Surface-Active Substance

To prevent the spread of acute gastroenteritis, which prevails during winter and is called the winter vomiting disease, it is necessary to develop a technology for the detection and removal of noroviruses (NVs) from contaminated water. In this study, the removal from municipal wastewater and concentration in foam of NVs using dispersed bubbles and milk casein as a surface-active protein were examined. Real-time reverse transcription loop-mediated isothermal amplification (RT-LAMP) as a new nucleic acid amplification method was used for NV detection. Although NV-GII was detected in two wastewater samples, NV-GI was not detected. By foam separation using dispersed bubbles, NV-GII was removed from wastewater and concentrated into the generated foam. The concentration of NV-GII in the collapsed foam water was more than approximately 8-fold higher than that in the wastewater. Because the generated foam can be analyzed by real-time RT-LAMP, it is possible to sensitively monitor NV pollution in aqueous environments. Here, we show for the first time the removal from aqueous solution and concentration of NVs in foam using dispersed bubbles and a surface-active substance.