Abstract

Thermal treatment at temperatures between 46.0 degrees C and 55.0 degrees C was evaluated as a method for sanitization of organic waste, a temperature interval less commonly investigated but important in connection with biological treatment processes. Samples of dairy cow feces inoculated with Salmonella Senftenberg W775, Enterococcus faecalis, bacteriophage phi X174, and porcine parvovirus (PPV) were thermally treated using block thermostats at set temperatures in order to determine time-temperature regimes to achieve sufficient bacterial and viral reduction, and to model the inactivation rate. Pasteurization at 70 degrees C in saline solution was used as a comparison in terms of bacterial and viral reduction and was proven to be effective in rapidly reducing all organisms with the exception of PPV (decimal reduction time of 1.2h). The results presented here can be used to construct time-temperature regimes in terms of bacterial inactivation, with D-values ranging from 0.37h at 55 degrees C to 22.5h at 46.0 degrees C and 0.45h at 55.0 degrees C to 14.5h at 47.5 degrees C for Salmonella Senftenberg W775 and Enterococcus faecalis, respectively and for relevant enteric viruses based on the phi X174 phage with decimal reduction times ranging from 1.5h at 55 degrees C to 16.5h at 46 degrees C. Hence, the study implies that considerably lower treatment temperatures than 70 degrees C can be used to reach a sufficient inactivation of bacterial pathogens and potential process indicator organisms such as the phi X174 phage and raises the question whether PPV is a valuable process indicator organism considering its extreme thermotolerance.

Keywords

Bovine feces; D-value; PPV; Salmonella; sanitization treatment; z-value

Published in

Journal of Environmental Science and Health, Part B
2014, Volume: 49, number: 9, pages: 679-689
Publisher: TAYLOR & FRANCIS INC

SLU Authors

• Vinnerås, Björn

  • Department of Energy and Technology, Swedish University of Agricultural Sciences
    

• Ottoson, Jakob

  • Department of Animal Biosciences, Swedish University of Agricultural Sciences
    

Sustainable Development Goals

SDG12 Ensure sustainable consumption and production patterns


UKÄ Subject classification

Environmental Sciences related to Agriculture and Land-use
Agricultural Science


Publication identifier

DOI: https://doi.org/10.1080/03601234.2014.922783

Permanent link to this page (URI)

https://res.slu.se/id/publ/67659