An environmental evaluation of urine-diverting dry toilets in Hiloweyn Camp, Dollo Ado, Ethiopia

• Published in: The Science of the total environment 2024-05, Vol.926, p.171838-171838, Article 171838
• Main Authors: Brown, Travis W., Murphy, Jennifer L., Akers, Patricia, Patrick, Molly, Hill, Vincent, Mattioli, Mia, Tsige, Yegerem, Adow, Ahmed, Abdirashid, Mohamed, Mohamed, Mohamed Nur, Githiri, David, Handzel, Thomas
• Format: Article
• Language: English
• Subjects: Ascaris ova; E. coli; Humanitarian emergencies; Pathogen inactivation; Sanitation; Urine-diverting dry toilets
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2024.171838

Safe and hygienic management of human waste is essential in humanitarian settings. Urine-diverting dry toilets (UDDTs) can enable this management in some humanitarian emergency settings. A seeded, longitudinal environmental study was conducted in Hiloweyn refugee camp, Dollo Ado, Ethiopia, to measure Escherichia coli and Ascaris suum ova inactivation within closed UDDT vaults and to document environmental conditions (temperature, moisture content, and pH) that could influence inactivation. Hiloweyn camp represented an optimal location for a desiccation-based sanitation technology such as the UDDT. E. coli and Ascaris ova inactivation was observed in UDDTs under warm, dry, alkaline conditions at 6, 9, and 12 months of storage; UDDTs with samples containing 2.8-log10 reduction in Ascaris ova viability was observed after 6 months. Additional laboratory-based studies were conducted to provide insights into the field study findings and study the impact of hydrated lime on E. coli and Ascaris ova inactivation. Results suggest that adding hydrated lime to elevate pH > 12 may increase inactivation and decrease storage time. Overall, UDDTs could contribute to the safe and hygienic management of human waste in comparable warm and dry humanitarian settings. [Display omitted] •Effective alternative sanitation options are needed in some humanitarian settings.•UDDT performance was assessed in Hiloweyn Camp, Ethiopia.•Substantial reductions in E. coli and Ascaris ova observed in stored UDDT waste.•Hydrated lime addition may decrease required UDDT waste storage time.•UDDTs could promote sustainable sanitation in comparable settings.