Differential removal of human pathogenic viruses from sewage by conventional and ozone treatments

Abstract

Sewage contains a mixed ecosystem of diverse sets of microorganisms, including human pathogenic viruses. Little is known about how conventional as well as advanced treatments of sewage, such as ozonation, reduce the environmental spread of viruses. Analyses for viruses were therefore conducted for three weeks in influent, after conventional treatment, after additional ozonation, and after passing an open dam system at a full-scale treatment plant in Knivsta, Sweden. Viruses were concentrated by adsorption to a positively charged filter, from which they were eluted and pelleted by ultracentrifugation, with a recovery of about 10%. Ion Torrent sequencing was used to analyze influent, leading to the identification of at least 327 viral species, most of which belonged to 25 families with some having unclear classification. Real-time PCR was used to test for 21 human-related viruses in inlet, conventionally treated, and ozone-treated sewage and outlet waters. The viruses identified in influent and further analyzed were adenovirus, norovirus, sapovirus, parechovirus, hepatitis E virus, astrovirus, pecovirus, picobirnavirus, parvovirus, and gokushovirus. Conventional treatment reduced viral concentrations by one to four log10, with the exception of adenovirus and parvovirus, for which the removal was less efficient. Ozone treatment led to a further reduction by one to two log10, but less for adenovirus. This study showed that the amount of all viruses was reduced by conventional sewage treatment. Further ozonation reduced the amounts of several viruses to undetectable levels, indicating that this is a promising technique for reducing the transmission of many pathogenic human viruses.

Detection and Characterization of Hepatitis E Virus Genotype 3 in Wastewater and Urban Surface Waters in Germany

“…So far, reports with quantified HEV concentrations in environmental waters are rare and mainly restricted to wastewater influent samples. The HEV concentrations in wastewater influents determined in this study correspond to the concentrations reported by Rodriguez-Manzano et al (2010), Masclaux et al (2013), Wang et al (2018b) and Miura et al (2016). In contrast to the findings of Masclaux et al (2013), where HEV RNA was detected more frequently in summer, no clear seasonal pattern of HEV RNA occurrence was observed in the present study, similar to the report of Ram et al (2016).…”

“…Ultracentrifugation and PEG precipitation are standard virus concentration methods for detection of HEV in sewage samples (Clemente-Casares et al 2003;Rodriguez-Manzano et al 2010;Masclaux et al 2013;Myrmel et al 2015;Ram et al 2016;Iaconelli et al 2017;Wang et al 2018b;Matos et al 2018). The 25% positive samples during the 1-year period using the PEG precipitation method were comparable to findings of Masclaux et al (2013) and Miura et al (2016), which reported rates of 32% and 22%, respectively.…”

Removal of Enteric Pathogens from Real Wastewater Using Single and Catalytic Ozonation

“…The conventional wastewater treatment reveals difficulty in removing both chemical and biological emerging contaminants from water [1][2][3][4][5][6][7]. Among these pollutants, pharmaceutical and personal care products, as well as enteric pathogens [8][9][10][11][12], are of concern.…”

Hepatitis E Virus Genotype 3 Genomes from RNA-Positive but Serologically Negative Plasma Donors Have CUG as the Start Codon for ORF3

“…Newly built libraries were amplified for 8 cycles and purified with AMPureXP-beads (Beckman Coulter, Brea, CA, USA) and thereafter analysed and loaded on an ion 318 chip and sequenced on an IonTorrent PGM with an Ion-PGM-Hi-Q-View-Sequencing Kit (ThermoFisher) as previously described [33]. The sequences obtained were imported into a CLC Genomic Workbench 9.5.1 (Qiagen, Hilden, Germany) and analysed as previously described [33]. The contigs and singleton reads were blasted against known HEV genomes using BLASTn, and a cut-off for E-value of 10 -3 for significant hits.…”