Abstract

It is challenging and expensive to monitor and test decentralized composting toilet systems, yet critical to prevent the mismanagement of potentially harmful and pathogenic end-product. Recent studies indicate that mixed latrine composting toilets can be inhibited by high ammonia content, a product of urea hydrolysis. Urine-diverting vermicomposting toilets are better able to accomplish the goals of remote site human waste management by facilitating the consumption of fecal matter by earthworms, which are highly sensitive to ammonia. The reliability of Solvita (R) compost stability and maturity tests were evaluated as a means of determining feedstock suitability for vermicomposting (ammonia) and end-product stability/completeness (carbon dioxide). A significant linear regression between Solvita (R) ammonia and free ammonia gas was found. Solvita (R) ranking of maturity did not correspond to ranking assigned by ammonium:nitrate standards. Solvita (R) ammonia values 4 and 5 contained ammonia levels below earthworm toxicity limits in 80% and 100% of samples respectively indicative of their use in evaluating feedstock suitability for vermicomposting. Solvita (R) stability tests did not correlate with carbon dioxide evolution tests nor ranking of stability by the same test, presumably due to in situ inhibition of decomposition and microbial respiration by ammonia which were reported by the Solvita (R) CO2 test as having high stability values. (C) 2013 Elsevier Ltd. All rights reserved.

Keywords

Composting toilet; Human feces; Solvita; Ammonia; Maturity; Stability

Published in

Waste Management
2013, Volume: 33, number: 7, pages: 1602-1606
Publisher: PERGAMON-ELSEVIER SCIENCE LTD

SLU Authors

• Vinnerås, Björn

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

UKÄ Subject classification

Other Environmental Engineering


Publication identifier

DOI: https://doi.org/10.1016/j.wasman.2013.03.021

Permanent link to this page (URI)

https://res.slu.se/id/publ/52990