Chemical free disinfection using the fluid disinfection system (FDS)™

This paper describes trials carried out with a disinfection system developed by Packaged Environmental Solutions (F'ES). The trials were carried out at the Woolgoolga Sewage Treatment Plant, which is operated by the Coffs Harbour City Council, in New South Wales. The system uses a heat disinfection system with heat exchange and recovery to minimise operating costs. The disinfection system can handle from 200 L/h to 20,000 L/h, and the current tests were conducted at a rate of about 300 L/h at a temperature of 85 –90°C with a retention time of about two and a half minutes. The unit was positioned after secondary treatment (activated sludge) and filtering (disc filters) and results were also obtained following the standard disinfection by chlorine for comparison. Both faecal coliforms and total coliforms were measured, before and after disinfection. Results indicate that FDS is a viable alternative to conventional disinfection methods for reuse of treated effluent.