Abstract |
The survival of indigenous enteric viruses in samples of unconcentrated and concentrated wastewater sludge eluates, which had been prepared using a combination beef extract elution-organic flocculation concentration procedure, was studied at 2, 23 and -70C. Changes of virus titer occurring in the samples were followed during an 84-day observation period, with rates of change then calculated by least-squares regression. Virus survival in both types of eluates was statistically dependent upon storage temperature. Based upon the observed rates of inactivation the average times which would be required for a 90 percent decrease (one log10 unit) in virus titer for unconcentrated eluates are 27 days at 23C, 198 days at 2C, and 375 days at -70C. The three study temperatures were selected to approximate holding of samples in an air conditioned room, fluid on wet ice (H2O) and frozen on dry ice (CO2). |