A COMPARISON BETWEEN HIGH RATE CHLORINE AND BROMINE DISINFECTION

The disinfection of combined sewer overflows (CSO) at satellite locations involves primarily the use of sodium hypochlorite (NaOCl). A typical process generally involves storage of liquid NaOCl, high-rate mixing, a control feed back loop measuring total residual chlorine (TRC), and a contact chamber. Owing to the highly variable nature of CSOs in quality and quantity of flow, improvements in the last several years have made CSO disinfection at remote locations more feasible. Recent developments in the application of a bromine compound, bromochlorodimethyhydantoin (BCDMH) presents an alternative with advantages in footprint, safety and storage. This paper presents comparisons of CSO disinfection employing NaOCl and BCDMH. In terms of effectiveness, toxicity, equipment employed and capital and O&M costs presently the costs of BCDMH are within 11 percent of the NaOCl costs. The more frequent use of BCDMH could reduce this difference.