Sanitary sewage disinfection with ultraviolet radiation and ultrasound

In the present scenario, the globe is facing a horrible situation due to an infectious virus SARS-CoV-2. Its RNA was found in sewage waters, there are still no studies on RNA contamination detected in the sewage, however, a possible treatment of sewage is suggested in this work. The disinfection stage is extremely important in the treatment of effluents, minimizing the impacts on the receiving body and promoting public health. In this context, the sequential use of ultrasound and ultraviolet radiation, on a bench scale, was investigated as a way to improve the disinfection of domestic effluents from the septic tank and of an anaerobic filter. The better quality of the anaerobic filter effluent influenced the performance of both processes, decreasing the concentration of organic load and turbidity, even so, the concentration of total coliforms and <i>Escherichia coli</i> occurred in the lowest quality effluent (septic tank). In the sequential application, synergistic effects of more than 1 log of inactivity were found. It is suggested that the disinfection methods applied in this work to inactivate gram-negative bacteria (<i>E. coli</i>) can also be applied to secondary treatment effluents, as well as being better tested for viruses, protozoa, and helminths.