Disinfection of Viral Indicators and Treatability Implications for WRRFs

摘要

This bench-top study evaluated the treatability of viral indicators (coliphages) versus traditional bacterial indicators (E. coli and enterococci) with the major wastewater disinfectants in response to the USEPA's ongoing evaluations of adding coliphages to future updates of the Recreational Water Quality Criteria (RWQC). The major disinfectants tested included sodium hypochlorite (free and combined chlorine), ultraviolet light (UV), peracetic acid (PAA), and ozone. The results suggest that facilities using sodium hypochlorite (in the presence of ammonia and forming chloramines) or peracetic acid could be affected more by coliphage criteria than plants using free chlorine or UV at the typical doses and contact times used in disinfection. Furthermore, for both chloramines and peracetic acid significant tailing was observed, suggesting that facilities with these disinfectants may have to improve upstream processes or change disinfectants to meet low coliphage criteria. Facilities using free chlorine, UV, or ozone are less likely to be affected by coliphage criteria, depending on the numerical value established for such criteria. This work is part of the WE&RF Study (U3R15) - Evaluating Fate of Coliphages in WRRFs and Potential Costs to Reduce Coliphages in WRRF Effluents.