INACTIVATION AND REPAIR OF ENTEROCOCCUS FAECALIS AND VIBRIO CHOLERA BY UV FOR BALLAST WATER TREATMENT

Abstract

Invasive aquatic species discharged through ballast water carried by ships to ensure stability is one of the serious problems posed nowadays in the marine environment. UV disinfection has been increasingly applied to microbial inactivation in ballast water mainly due to the advantages of non-toxic by-products and low maintenance costs. In this study, Enterococcus faecalis (DSM 20478) and Vibrio cholerae (NCTC 7253) were selected as indicators to investigate the UV susceptibility and repair potential. Results indicated that V. cholerae is more sensitive to UV inactivation than E. faecalis. For repair, LP UV resulted in a greater level of light repair than MP and the light repair results were all higher than dark repair. The tested three water quality parameters including salinity, turbidity and temperature were found to decrease log removal of UV. Effects of salinity and turbidity on repair were related with different UV sources, but the temperature usually inhabits the repair.