Virus Removal by an On-Site Wastewater Treatment and Recycling System

On-site wastewater reclamation and recycling systems are a useful option in areas where moratoriums exist on sewer connections or water shortages encourage maximum use of all water resources. The Cycle-Let Recycling System is used to treat wastewater from offices, shopping centers, and commercial and public facilities. The system is designed to produce reclaimed water for toilet and urinal flushing or landscape irrigation by anoxic and aerobic biological treatment followed by ultrafiltration, passage through activated carbon, and disinfection by ultraviolet light. A full scale operating system was evaluated for its removal of the coliphage MS-2, rotavirus SA-11, poliovirus type 1 by seeding these viruses into the mixed liquor tanks before treatment. In addition, samples were collected for naturally occurring viruses after completion of the tests. Four hundred liter samples were processed and tested for the animal viruses after each of the treatment processes,No animal viruses could be detected after ultrafiltration, indicating a reduction of at least 99.9998%. MS-2 coliphage was reduced by 99.93% by the ultrafiher and more than 99.999% after disinfection. It appears that detectable levels of animal viruses are unlikely to survive this treatment process.