KINETICS OF PATHOGEN DESTRUCTION DURING STORAGE OF DEWATERED BIOSOLIDS

The kinetics of pathogen destruction were determined during storage of digested and dewatered wastewater treatment biosolids to obtain relat ionships between temperature and duration of biosolids storage. Biosol ids, seeded with Salmonella typhimurium, Yersinia enterocolitica, Camp ylobacter jejuni, bacteriophage f2, poliovirus, and Ascaris suum eggs were incubated at 5 degrees, 22 degrees, 38 degrees, and 49.5 degrees C, under both aerobic and anaerobic conditions for up to 62 days. Dest ruction of pathogens in stored biosolids occurred at all temperatures examined; however, rates increased with increasing temperature. There was no significant difference between the destruction of pathogens und er aerobic or anaerobic conditions at all temperatures studied. At 50 degrees C, the decay rate of S. typhimurium, Y. enterocolitica, bacter iophage f2, poliovirus, and A. suum eggs was estimated to be 1.13, 1.1 0, 1.54, 0.81, and 0.21 log(10) reductions per day, respectively.