A Somatic Coliphage Threshold Approach To Improve the Management of Activated Sludge Wastewater Treatment Plant Effluents in Resource-Limited Regions
| Autor: | Luz Chacón, Rosario Achí, Melissa Solano, Carolina Santamaría-Ulloa, Erin M. Symonds, Kenia Barrantes, Carmen Valiente, Lizeth Taylor, Liliana Reyes |
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| Rok vydání: | 2020 |
| Předmět: |
Costa Rica
Enteric viruses 0208 environmental biotechnology Sewage Wastewater treatment 02 engineering and technology Wastewater 010501 environmental sciences Reuse medicine.disease_cause Coliphages Waste Disposal Fluid 01 natural sciences Applied Microbiology and Biotechnology medicine Coliphage Effluent 0105 earth and related environmental sciences Ecology biology Public and Environmental Health Microbiology business.industry Somatic coliphage biology.organism_classification 020801 environmental engineering Biotechnology Activated sludge Fecal indicator bacteria Norovirus Environmental science Sewage treatment Threshold values business Food Science |
| Zdroj: | Appl Environ Microbiol Applied and Environmental Microbiology, vol.86(17), pp.1-52 Kérwá Universidad de Costa Rica instacron:UCR |
| ISSN: | 1098-5336 0099-2240 |
| Popis: | Effective wastewater management is crucial to ensure the safety of water reuse projects and effluent discharge into surface waters. Multiple studies have demonstrated that municipal wastewater treatment with conventional activated sludge processes is inefficient for the removal of a wide spectrum of viruses in sewage. In this study, a well-accepted statistical approach was used to investigate the relationship between viral indicators and human enteric viruses during wastewater treatment in a resource-limited region. Influent and effluent samples from five urban wastewater treatment plants (WWTPs) in Costa Rica were analyzed for somatic coliphage and human enterovirus, hepatitis A virus, norovirus genotypes I and II, and rotavirus. All WWTPs provide primary treatment followed by conventional activated sludge treatment prior to discharge into surface waters that are indirectly used for agricultural irrigation. The results revealed a statistically significant relationship between the detection of at least one of the five human enteric viruses and somatic coliphage. Multiple logistic regression and receiver operating characteristic curve analysis identified a threshold of 3.0 × 103 (3.5 log10) somatic coliphage PFU per 100 ml, which corresponded to an increased likelihood of encountering enteric viruses above the limit of detection (>1.83 × 102 virus targets/100 ml). Additionally, quantitative microbial risk assessment was executed for farmers indirectly reusing WWTP effluent that met the proposed threshold. The resulting estimated median cumulative annual disease burden complied with World Health Organization recommendations. Future studies are needed to validate the proposed threshold for use in Costa Rica and other regions. IMPORTANCE Effective wastewater management is crucial to ensure safe direct and indirect water reuse; nevertheless, few countries have adopted the virus log reduction value management approach established by the World Health Organization. In this study, we investigated an alternative and/or complementary approach to the virus log reduction value framework for the indirect reuse of activated sludge-treated wastewater effluent. Specifically, we employed a well-accepted statistical approach to identify a statistically sound somatic coliphage threshold value which corresponded to an increased likelihood of human enteric virus detection. This study demonstrates an alternative approach to the virus log reduction value framework which can be applied to improve wastewater reuse practices and effluent management. |
| Databáze: | OpenAIRE |
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