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Research article2009Peer reviewedOpen access

Inactivation of Ascaris Eggs in Source-Separated Urine and Feces by Ammonia at Ambient Temperatures

Nordin, Annika; Nyberg, Karin; Vinnerås, Björn

Abstract

Sustainable management of toilet waste must prevent disease transmission but allow reuse of plant nutrients. Inactivation of uterus-derived Ascaris suum eggs was studied in relation to ammonia in source-separated urine without additives and in human feces to which urea had been added, in order to evaluate ammonia-based sanitation for production of safe fertilizers from human excreta. Urine was used concentrated or diluted 1:1 and 1:3 with tap water at 4, 14, 24, and 34 degrees C. Fecal material, with and without ash, was treated with 1% or 2% (wt/wt) urea at 24 and 34 C. At 34 degrees C eggs were inactivated in less than 10 days in urine and in amended feces. At 24 degrees C only feces with 2% (wt/wt) urea or 1% (wt/wt) urea at high pH (10) inactivated all eggs within 1 month, and no inactivation was observed after 75 days in urine diluted 1: 3 (18 +/- 11 mM NH(3)). At temperatures of >= 24 degrees C, NH(3) proved to be an efficient sanitizing agent in urine and feces at concentrations of >= 60 mM. Treating fecal material at 34 degrees C can give a 6-log(10) egg inactivation within 1 month, whereas at 24 degrees C 6 months of treatment is necessary for the same level of egg inactivation. At temperatures of 14 degrees C and below, inactivation rates were low, with viable eggs after 6 months even in concentrated urine.

Published in

Applied and Environmental Microbiology
2009, Volume: 75, number: 3, pages: 662-667
Publisher: AMER SOC MICROBIOLOGY

      SLU Authors

    • Sustainable Development Goals

      Ensure sustainable consumption and production patterns

      UKÄ Subject classification

      Environmental Sciences related to Agriculture and Land-use
      Agricultural Science
      Food Science

      Publication identifier

      DOI: https://doi.org/10.1128/AEM.01250-08

      Permanent link to this page (URI)

      https://res.slu.se/id/publ/50204