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Electrochemically and Bioelectrochemically Induced Ammonium Recovery
Published on: January 22, 2015
Sanitation of faeces from source-separating dry toilets using urea
A Nordin1, J R Ottoson, B Vinnerås
1Department of Energy and Technology, Swedish University of Agricultural Sciences, Uppsala, Sweden. annika.nordin@et.slu.se
Journal of Applied Microbiology
|May 12, 2009
Summary
Adding urea to human excreta effectively sanitizes feces, transforming waste into safe fertilizer. This method rapidly inactivates pathogens like Salmonella Typhimurium, making human waste a valuable resource for agriculture.
Area of Science:
- Environmental microbiology
- Sanitation science
- Sustainable agriculture
Background:
- Human excreta poses significant sanitation and health risks.
- Nutrient-rich human waste is a potential resource for fertilizer.
- Current methods for excreta treatment can be complex or inefficient.
Purpose of the Study:
- To develop a simple and effective method for sanitizing human feces using urea.
- To assess the potential of urea-treated excreta as safe fertilizer.
- To evaluate the inactivation of specific pathogens and a bacteriophage in feces treated with urea.
Main Methods:
- Urea was added to fecal matter at varying concentrations (0.5-2% w/w).
- Inactivation of Salmonella Typhimurium, Enterococcus spp., and a Salmonella Typhimurium bacteriophage was monitored.
- Experiments were conducted at different temperatures (14, 24, and 34°C).
Main Results:
- Urea addition significantly enhanced pathogen inactivation.
- Inactivation rates correlated positively with ammonia concentration and temperature.
- Salmonella Typhimurium was most sensitive; Enterococcus spp. showed persistence; bacteriophages were most resistant.
Conclusions:
- Urea treatment effectively reduces Salmonella levels to meet safety requirements for fertilizer reuse.
- A 6 log(10) reduction of Salmonella can be achieved within weeks, depending on temperature and urea concentration.
- Urea treatment is a robust and efficient method for the safe recycling of plant nutrients from human waste.
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