Simultaneous removal of rotavirus and adenovirus from artificial ground water using hydrochar derived from swine feces.

Hydrothermal carbonization technology can convert fecal waste into a valuable carbonaceous product referred to as hydrochar. We investigated the potential of fecal waste-derived hydrochar as an adsorbent for virus removal in water treatment. Swine feces was hydrothermally treated under two conditions: at 180 °C for 2 h and 230 °C for 7 h. The resulting solid products (hydrochar) were evaluated as virus adsorbents in water treatment. Simultaneous removal of pathogenic rotavirus (RV) and human adenovirus (HAdV) was investigated using a sand column set-up of 10 cm bed height with and without hydrochar supplement (1.5%, w/w). The removal efficiency of both viruses in a hydrochar-amended column was >3 log (complete removal). The amount of virus released in deionized water when flushed into the virus-retaining columns indicated that the secondary energy minimum played a more important role in RV retention than that of HAdV. Zeta-potential and hydrophobicity measurements on hydrochar materials indicated that the improved virus removal performance of hydrochar-amended columns was induced by the provision of extra hydrophobic surfaces. This study provides evidence that fecal waste-derived hydrochar can be used as a competent virus adsorbent.