Persistence of Surrogates for High Consequence Viral and Bacterial Pathogens in a Pilot-Scale Activated Sludge Treatment System
Citation:
Schupp, D., A. Burdsall, R. Silva, L. Heckman, R. Krishnan, Jeff Szabo, AND M. Magnuson. Persistence of Surrogates for High Consequence Viral and Bacterial Pathogens in a Pilot-Scale Activated Sludge Treatment System. PLOS ONE . Public Library of Science, San Francisco, CA, 17(10):e0275482, (2022). https://doi.org/10.1371/journal.pone.0275482
Impact/Purpose:
Removal or inactivation of high consequence public health pathogens during wastewater treatment can be critical for the safety of workers, the public, and downstream water bodies. This study utilizes organism viability to evaluate the persistence of three pathogen surrogates in bio-contaminated wastewater using a pilot-scale activated sludge treatment (AST) system, operated to mimic treatment processes of large-scale plants. Depending on AST operating conditions, Bacillus globigii spores, surrogate for Bacillus anthracis, persisted in the AST system for at least a 50 day observation period. MS2 bacteriophage, surrogate for Poliovirus and other non-enveloped enteric viruses, was observed for up to 35 days after introduction. Phi-6 bacteriophage, a surrogate for Ebola virus and other enveloped viruses, was detected for no more than 4 days after introduction, even if the AST system was operated to provide three times slower solids removal than for the other surrogates. These results may suggest similar persistence for the surrogated pathogens, leading to appropriate consequence management actions.
Description:
This study utilizes organism viability to evaluate the persistence of three pathogen surrogates in bio-contaminated wastewater using a pilot-scale activated sludge treatment (AST) system, operated to perform like a large-scale wastewater treatment process. The persistence of high consequence public health pathogens in a wastewater treatment system can significantly impact worker safety, as well as the public and downstream water bodies, particularly if the system is forced to shut down the treatment processes. This study utilizes organism viability to compare the persistence of three pathogen surrogates in wastewater using a pilot-scale activated sludge treatment (AST) system, operated to mimic treatment processes of large-scale plants. Bacillus globigii spores, surrogate for Bacillus anthracis, persisted in the AST system for at least a 50-day observation period leading to a possible steady condition far beyond the solid retention time for sludge particles. MS2 bacteriophage, surrogate for Poliovirus and other non-enveloped enteric viruses, was observed for up to 35 days after introduction, which largely and expectedly correlated to the measured solid retention time. Phi-6 bacteriophage, a surrogate for Ebola virus and other enveloped viruses, was detected for no more than 4 days after introduction, even though the AST system was operated to provide three times slower solids removal than for the other surrogates. This suggests Phi-6 is subject to inactivation under AST conditions rather than physical removal. These results may suggest similar persistence for the surrogated pathogens, leading to appropriate consequence management actions.
URLs/Downloads:
DOI: Persistence of Surrogates for High Consequence Viral and Bacterial Pathogens in a Pilot-Scale Activated Sludge Treatment System