Different Fates of FRNA Phage Genotypes in a Sequencing Batch Reactor Treating Domestic Wastewater in a Satellite City of Hanoi

摘要

FRNA phages have been used as indicators of human enteric viruses for microbial water safety management. In this study, the fate of each FRNA phage genotype was investigated in a sequencing batch reactor treating domestic wastewater in a satellite city of Hanoi, Vietnam. This plant has a capability to process 28,000 m~3 of wastewater per day with HRT less than 6 hours under 3-hour cycle operation. Sequencing batch reactor allows us to collect time-series samples, which contributes to dynamic assessment of virus fate in a biological treatment. Integrated cell culture-RT-qPCR coupled with MPN method was applied to detect four genotypes of FRNA phages (GI, GII, GUI, and GIV) using WG49 as a host strain and genotype specific PCR. FRNA phages adsorbed to sludge were recovered following the EPA method. Non-negligible amount of FRNA phage GIV was found in the influent and tended to decrease more than the other genotypes during treatment. FRNA phage GII and GIII were more abundant in influent than GI and GIV, while FRNA phage GI was majority in the effluent. FRNA phage GIII can possibly be used as an indicator of contamination of domestic wastewater which received insufficient treatment.