Influence of DOC on the inactivation efficacy of ozonation assessed with Clostridium perfringens and a lab-scale continuous flow system

Abstract

Routine quality monitoring for fecal indicators after ozonation at the river-lake waterworks Weesperkarspel of Amsterdam Water Supply (AWS) show large variation in inactivation. The influence of the high DOC in the water on the inactivation efficiency was investigated. Results showed a higher inactivation of Clostridium perfringens in the AWS water than in a water with low DOC at the same CT conditions. The contribution of the gas feed chamber to the overall inactivation of C. perfringens was high in the AWS water and was reduced after DOC reduction with GAC. This result may alter the current CT concept of the process. Further research will be focused on the ozone dosage strategy and control related to the required CT for inactivation and the production of by-products.