Viable ova of Ascaris lumbricoides, an indicator organism for pathogens, are frequently found in feces-derived compost produced
from ecological toilets, demonstrating that threshold levels of time, temperature, pH, and moisture content for pathogen
inactivation are not routinely met. Previous studies have determined that NH3 has ovicidal properties for pathogens, including
Ascaris ova. This research attempted to achieve Ascaris inactivation via NH3 under environmental conditions commonly found
in ecological toilets and using materials universally available in an ecological sanitation setting, including compost (feces and
sawdust), urine, and ash. Compost mixed with stored urine and ash produced the most rapid inactivation, with significant inactivation
observed after 2 weeks and with a time to 99% ovum inactivation (T99) of 8 weeks. Compost mixed with fresh urine and
ash achieved a T99 of 15 weeks, after a 4-week lag phase. Both matrices had relatively high total-ammonia concentrations and pH
values of >9.24 (pKa of ammonia). In compost mixed with ash only, and in compost mixed with fresh urine only, inactivation
was observed after an 11-week lag phase. These matrices contained NH3 concentrations of 164 to 173 and 102 to 277 mg/liter,
respectively, when inactivation occurred, which was below the previously hypothesized threshold for inactivation (280 mg/liter),
suggesting that a lower threshold NH3 concentration may be possible with a longer contact time. Other significant results include
the hydrolysis of urea to ammonia between pH values of 10.4 and 11.6, above the literature threshold pH of 10.