5861: MICROBIOLOGICAL ASSESSMENTS OF COMPOST TOILETS: IN-SITU MEASUREMENTS AND LABORATORY STUDIES OF THE SURVIVAL OF FECAL MICROBIAL INDICATORS USING SENTINEL CHAMBERS

Tønner-Klank, L.; Møller, J.; Forslund, A. and Dalsgaard, A. (2005) MICROBIOLOGICAL ASSESSMENTS OF COMPOST TOILETS: IN-SITU MEASUREMENTS AND LABORATORY STUDIES OF THE SURVIVAL OF FECAL MICROBIAL INDICATORS USING SENTINEL CHAMBERS. Waste Management and Research.^*

Summary

Compost toilet systems were assessed for their ability to reduce microbial indicators and pathogens. Bacterial pathogens were not detected in any samples indicating a low survival rate in composting feces and/or an initial low occurrance. Indicator bacteria showed large variations with no clear trend of lower bacterial numbers after longer storage.
In controlled composting experiments , thermophilic conditions were only reached when amendments were made (grass and a sugar solution). Even then it was impossible to ensure a homogenous temperature in the composting faecal material and therefore difficult to achieve a uniform reduction and killing of indicator organisms.
Thermotolerant coliforms, Salmonella Typhimurium Phage 28B and eggs of Ascaridia galli proved useful as indicators. However, regrowth was detected for enterococci and total numbers of bacteria grown at 36 °C. These indicator parameters may therefore overestimate the level of other (pathogenic) bacteria present in the material and can based on our studies not be recommended for use as indicator organisms in composting toilet systems.
Addition of indicator bacteria to fecal material contained in semi-permeable capsules proved to be a useful technique. Thus, microorganisms, e.g. bacteria, virus and parasites can be added in known concentrations to materials to test their survival over time.

Archive Staff Only: edit this record