We launched pilot tests about 3 months ago to optimize the hygienization of dry toilet residues (sawdust and faeces mix) collected from about 30 households through composting. We would like the opinion of other researchers on this subject, and especially bibliographical references.
A generally fecal-phobic society reacts to the thought with a mix of snickering interest and fearful aversion, all dispatched in a single flush.
Bench-scale composting of source-separated human faeces for sanitation( https://doi.org/10.1016/j.wasman.2008.06.022 )
Abstract: In urine-diverting toilets, urine and faeces are collected separately so that nutrient content can be recycled unmixed. Faeces should be sanitised before use in agriculture fields due to the presence of possible enteric pathogens. Composting of human faeces with food waste was evaluated as a possible method for this treatment. Temperatures were monitored in three 78-L wooden compost reactors fed with faeces-to-food waste substrates (F:FW) in wet weight ratios of 1:0, 3:1 and 1:1, which were observed for approximately 20 days. To achieve temperatures higher than 15 °C above ambient, insulation was required for the reactors. Use of 25-mm thick styrofoam insulation around the entire exterior of the compost reactors and turning of the compost twice a week resulted in sanitising temperatures (⩾50 °C) to be maintained for 8 days in the F:FW = 1:1 compost and for 4 days in the F:FW = 3:1 compost. In these composts, a reduction of >3log10 for E. coli and >4log10 for Enterococcus spp. was achieved. The F:FW = 1:0 compost, which did not maintain ⩾50 °C for a sufficiently long period, was not sanitised, as the counts of E. coli and Enterococcus spp. increased between days 11 and 15. This research provides useful information on the design and operation of family-size compost units for the treatment of source-separated faeces and starchy food residues, most likely available amongst the less affluent rural/urban society in Uganda. Source : Waste Management,Volume 29, Issue 2, February 2009, Pages 585-589
Please find enclosed an interesting relevant PDF..
Dear Gaston,
according to Faechem et al. (1983, p. 79) it would require one day at 50°C to kill all pathogens in the substrate. Of course, that means the whole composting substrate would have to reach this temperature. At lower temperatures, for instance at the edges of the composting heap/bin, it would take longer.
For an extensive list of references you may take a look at https://www.sswm.info/node/8241
One book, which I often recommend from that list, is "The Humanure Handbook" by Joseph Jenkins.
Best Regards,
Daniel
Feachem, R., Mara, D. D., & Bradley, D. J. (1983). Sanitation and disease. Washington DC, USA:: John Wiley & Sons. http://documents.worldbank.org/curated/en/704041468740420118/pdf/multi0page.pdf
The Chinese are achieving faster turnaround times treating sewage sludge using higher temperatures and re-cycling the high temperature bacteria (see attached). BTW Anoop I think the thought of excreting in fresh drinking water should become repugnant!
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