Inactivation of reovirus: Impact of temperature and low-lime dose on survival in digested and dewatered biosolids

The resistance of reovirus to inactivation by mesophillic and thermophillic temperatures was investigated and compared to existing inactivation patterns for poliovirus, the most commonly used enteric virus indicator. The resistance of reovirus to alkaline condition resulting from the addition of lime (CaO) to biosolids was also examined. Phase one involved the incubation of reovirus in a buffered solution for a 28-day period at different temperatures ranging from 4°C to 50°C. This phase also involved reovirus incubation at thermophillic temperatures ranging from 50°C to 55°C for a 30-minute period. The second phase looked at reovirus survival in biosolids mixed with lime doses ranging from 0 to 100g lime per kg dry biosolids over a 23-day period. Reovirus was more resistant to inactivation caused by long-term storage under mesophilic temperature conditions than poliovirus. Reovirus also was more resistant to inactivation caused by short-term storage under thermophilic temperature conditions than poliovirus. Treatment doses of 80g lime per kg dry biosolids and greater were able to achieve class A levels for enteric viruses.