Assessment of human adenovirus removal by qPCR in an advanced water reclamation plant in Georgia, USA

Abstract

Aims: To assess human adenoviruses (HAdVs) removal in an advanced wastewater treatment facility and compare two parallel tertiary treatment methods for the removal of HAdVs.

Methods and results: Tangential flow ultrafiltration was used to concentrate the water samples, and HAdVs were precipitated by polyethylene glycol. HAdVs were detected only by TaqMan real-time PCR, and HAdV genotype was determined by DNA sequence. HAdVs were detected in 100% of primary clarification influent, secondary clarification effluent and granular media (GM) filtration effluent samples but only in 31·2% of membrane filtration (MF) effluent and 41·7% of final effluent (FE) samples, respectively. The average HAdVs loads were significantly reduced along the treatments but HAdVs were still present in FE. Comparison of two parallel treatments (GM vs MF) showed that MF was technically superior to GM for the removal of HAdVs.

Conclusions: These findings indicate that adenoviruses are not completely removed by treatment processes. MF is a better treatment for removal of adenoviruses than GM filtration. Because only qPCR was used, the results only indicate the removal of adenovirus DNA and not the infectivity of viruses.

Significance and impact of the study: Presence of HAdVs in FE by qPCR suggests a potential public health risk from exposure to the treated wastewater and using the FE for recreational or water reuse purposes should be cautious.