Disinfecting Secondary Wastewater Effluent Using the CT Approach

The Metro Wastewater Reclamation District (District) is completing disinfection improvements at its Robert W. Hite Treatment Facility (RWHTF) to convert from a gas-based chlorine and sulfur dioxide system for disinfection and dechlorination to a liquid-based system using sodium hypochlorite and sodium bisulfite. The new system will be operated using the CT disinfection approach—a process widely used for drinking water disinfection, but with limited applications in wastewater treatment plants to date. This paper describes the CT approach for disinfection of secondary wastewater effluent at the RWHTF and how it was implemented as part of the plant's conversion to a liquid-based disinfection and dechlorination system.