Grantee Research Project Results
2022 Progress Report: Developing surrogate-based crediting frameworks for virus control through water recycling facilities
EPA Grant Number: R840256Title: Developing surrogate-based crediting frameworks for virus control through water recycling facilities
Investigators: Wigginton, Krista , Haas, Charles N. , Gerrity, Daniel , Pecson, Brian , Olivieri, Adam
Institution: University of Michigan - Ann Arbor
EPA Project Officer: Ludwig-Monty, Sarah
Project Period: August 1, 2021 through July 31, 2024
Project Period Covered by this Report: August 1, 2021 through July 31,2022
Project Amount: $1,239,980
RFA: Viral Pathogen and Surrogate Approaches for Assessing Treatment Performance in Water Reuse (2021) RFA Text | Recipients Lists
Research Category: Water Treatment
Objective:
1.Generate Data: Develop robust virus log reduction values (LRV) datasets by systematic manipulation of unit processes
in high-throughput bench-scale experiments.
2. Develop Models: Develop and validate mechanistic and/or numerical models for virus LRVs
based on operational and water quality parameters.
3. Develop Frameworks: Develop surrogate-based LRV crediting frameworks based on conservative
interpretation of data and models.
4. Stakeholder Communication: Facilitate industry adoption of LRV crediting frameworks through
data communication and regulatory engagement.
Progress Summary:
Systematic literature reviews were conducted on Virus Reduction through Secondary Biological Treatment, Virus Reduction through Coagulation, Flocculation, and Sedimentation, and Virus Reduction through Sub-Residual Ozone Treatment.
The review on Secondary Biological Treatment resulted in data on virus reduction and water quality parameters from 34 of the 54 studies. Early studies relied exclusively on culture data, whereas more recent studies generally rely on molecular data. The molecular data seems to yield lower LRVs, including for norovirus and rotavirus, but few studies show a direct comparison of culture and molecular data. Thus, it is not clear whether the low LRVs for rotavirus and norovirus are virus-specific or method-related. The proposed experimental work will address this knowledge gap.
The literature review on Virus Reduction through Coagulation, Flocculation, and Sedimentation (CFS) identified several studies evaluating the impact of CFS on typical drinking water quality parameters including TOC and turbidity reduction. A smaller subset of studies evaluated virus removal through these processes and found that optimum conditions for TOC and turbidity removal were frequently similar or identical to those needed for maximum virus removal. The virus log reduction values (LRVs) achieved by CFS were observed to vary widely depending on factors like source water quality, coagulant type, coagulant dose, virus type, and method of virus quantification.
Finally, during the literature review of Virus Reduction through Sub-Residual Ozone Treatment only a few studies were identified that investigated the impact of sub-residual ozone treatment on virus inactivation. There were two important conclusions from this review: 1) Large variation in virus log reduction exists based on source water quality and ozone dose; 2) Correlations are possible between virus inactivation and factors including UV254 absorbance, total fluorescence, and other trace organic chemical degradation.
At the end of this project year, experimental plans for each three methods have been drafted and reviewed and commented on by the research team. Comments and suggestions are being integrated for a second draft of the plans.
Virus Reduction through Secondary Biological Treatment (SNWA)
We developed an experimental plan and have completed 7 weeks of routine sampling and associated water quality and virus analyses. The paired samples have been analyzed for male-specific and somatic coliphages using the double agar layer culture method. Additional analyses include flow cytometry with ‘live/dead’ staining, virus concentration with InnovaPrep concentrating pipettes, and nucleic acid extraction.
Virus Reduction through Coagulation, Flocculation, and Sedimentation (Trussell Tech)
Testing will compare the behavior of human virus(es) to the bacteriophages in order to identify an appropriate indicator that will be used for the majority of the studies. The test plan intends to identify surrogate parameters that can be measured online (e.g., TOC, turbidity, UVA) and used to quantify the level of virus reduction occurring through the CFS processes.
Virus Reduction through Sub-Residual Ozone Treatment (UM)
A national transect of wastewater treatment samples will be taken following biological treatment. The water quality parameters, such as temperature, pH, turbidity, and total organic carbon content, of each will be measured using standard methods. These experiments will address the contribution of both ozone and hydroxyl radicals to the inactivation of different surrogate bacteriophages and native human pathogens in a range of wastewater effluents.
Future Activities:
The Regulatory Advisory Committee (RAC) has been recruited and a meeting will be held in the next quarter to review and discuss the plans in order to finalize the plans and start experiments later that quarter. Bench-top experiments with sub-residual ozone (UMich), biological treatment (SNWA), and coagulation/flocculation/sedimentation (Trussell Tech) will be conducted over the next year. Model development (Objective 2) will begin as data is generated. Team members will submit abstracts to begin presenting work at national conferences in summer/fall 2023.
Journal Articles:
No journal articles submitted with this report: View all 3 publications for this projectSupplemental Keywords:
Carbon-based advanced treatment (CBAT), direct potable reuse, indirect potable reuse, virus log removal values, sub-residual ozone, biological treatment,coagulation/flocculation/sedimentation.
Progress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.