INACTIVATION OF F-SPECIFIC RNA BACTERIOPHAGE GENOTYPES IN SECONDARY EFFLUENTS BY CHLORINE AND ULTRAVIOLET DISINFECTION, AND IDENTIFICATION OF SURVIVING STRAINS AFTER DISINFECTION USING NEXT GENERATION SEQUENCING

Abstract

 In this study, we investigated the inactivation of F-specific RNA bacteriophage (FRNAPH) genotypes I, II, III, and IV (GI, GII, GIII, and GIV, respectively) in secondary effluents by chlorine and ultraviolet disinfection and identified surviving FRNAPH strains after disinfection using next generation sequencing (NGS). The resistance of GII–GIV to chlorination was higher than that of GI in batch chlorine disinfection experiments, whereas the resistance of all four genotypes was similar in the FRNAPH-spiked batch chlorine disinfection experiments using the propagated indigenous FRNAPH genotypes in secondary effluents. GI showed the highest persistence to ultraviolet disinfection, followed by GII, GIII, and GIV in batch ultravi-olet disinfection experiments. Two strains belonging to GII were detected by NGS only in both chlorine and ultraviolet disinfected samples, suggesting that these strains may have higher persistence to both the disinfection treatments than that of other FRNAPH strains.