Removal of rotavirus and adenovirus from artificial ground water using hydrochar derived from sewage sludge

Aims: To determine the pathogenic virus removal performance of an adsorbent produced from hydrothermal carbonization of sewage sludge. Methods and Results: The removal of human pathogenic rotavirus and adenovirus was investigated with columns of 10 cm saturated sand with and without amendments of 1·5% (w/w) hydrochar. Virus concentrations were determined with reverse transcription (RT) quantitative polymerase chain reaction (qPCR). The experiments with sand showed 1 log removal, while the columns with 1·5% (w/w) hydrochar amendment showed 2 to >3 log removal for both viruses. Deionized (DI) water flushing into the virus-retaining columns revealed that the secondary energy minimum played a larger role in the attachment of rotavirus onto hydrochar surfaces than adenovirus. Improved virus removal may be attributed to the introduction of hydrophobic and/or meso-macro surface structures of the hydrochar providing favourable attachment sites for viruses. Conclusions: Hydrochar amended sand beds showed improved virus removal efficiencies exceeding 99·6% corresponding to 2·4 log removal. The addition of humic acid in the influent did not hinder the adsorptive removal of viruses. Significance and Impact of the Study: This study suggests that hydrochar derived from sewage sludge can be used as an adsorbent for virus removal in water treatment.