Towards sustainable sanitation: Mitigating microbial health risks in the production of urine-derived fertilizers in South Africa
Event details
| Date | 11.11.2014 |
| Hour | 16:15 › 17:15 |
| Speaker | Dr Heather N. Bischel, Environmental Chemistry Laboratory (LCE) |
| Location | |
| Category | Conferences - Seminars |
Abstract:
South Africa aims to achieve universal access to sanitation services. Aggressively pursuing this goal, the eThekwini Municipality of Durban, South Africa installed over 80,000 urine-diverting dry toilets (UDDTs) since the early 2000s at households in peri-urban regions of the city. Urine from these toilets is typically diverted from households into soak pits. However, approximately two thirds of phosphorus and 80% of nitrogen in human excrement are contained in the urine fraction and could be applied in agriculture either directly or in a processed fertilizer form. The VUNA project, sponsored by the Bill & Melinda Gates Foundation, aims to design and optimize the recovery of nutrients from urine in Durban as part of a decentralized sanitation system that is affordable for the poor, produces a valuable fertilizer, and reduces environmental pollution.
Little systematic evaluation regarding the health risks determinants in urine and microbial treatment efficacy of urine nutrient recovery processes has been conducted. Source-separated urine contains excreted pharmaceuticals as well as fecal pathogens resulting from cross-contamination of collected urine with fecal matter. This presentation provides an overview of the VUNA project and specifically addresses the presence of human pathogens in urine storage tanks throughout Durban. The pathogen inactivation performance of urine nitrification moving bed biofilm reactors (MBBRs) that are used to produce a nitrogen- and phosphorous-rich fertilizer is further evaluated.
While urine diversion and nutrient recovery have typically been implemented as grassroots or community-driven initiatives, the magnitude of the UDDT installation in the eThekwini Municipality will allow an evaluation of the potential for urine nutrient recovery processes at scale. A hygiene evaluation is particularly important in such a large-scale urban or peri-urban setting in which urine storage times are reduced and fertilizer production rates are high.
Short biography:
Heather N. Bischel is Postdoctoral Researcher interested in safe and efficient reuse of water resources and sustainable sanitation to improve environmental and human health. As part of the Laboratory of Environmental Chemistry at EPFL and the VUNA project, she works in collaboration with the Swiss Federal Institute of Aquatic Science and Technology (Eawag), the eTheKwini Water and Sanitation (EWS) Municipality, and the University of Kwa-Zulu Natal (www.eawag.ch/vuna). VUNA aims to recover nutrients from urine in Durban, South Africa as part of a decentralized sanitation system that is affordable for the poor, produces a valuable fertilizer, and reduces environmental pollution. Previously, she worked at the US NSF Engineering Research Center for Re-inventing the Nation’s Urban Water Infrastructure (ReNUWIt) to address technological and management challenges associated with recycling wastewater for streamflow augmentation and ecosystem enhancement. Heather earned a Ph.D. and M.Sc. from the Environmental Engineering & Science Program at Stanford University (2011, 2007) and a B.S. in Civil and Environmental Engineering from the University of California, Berkeley (2005).
South Africa aims to achieve universal access to sanitation services. Aggressively pursuing this goal, the eThekwini Municipality of Durban, South Africa installed over 80,000 urine-diverting dry toilets (UDDTs) since the early 2000s at households in peri-urban regions of the city. Urine from these toilets is typically diverted from households into soak pits. However, approximately two thirds of phosphorus and 80% of nitrogen in human excrement are contained in the urine fraction and could be applied in agriculture either directly or in a processed fertilizer form. The VUNA project, sponsored by the Bill & Melinda Gates Foundation, aims to design and optimize the recovery of nutrients from urine in Durban as part of a decentralized sanitation system that is affordable for the poor, produces a valuable fertilizer, and reduces environmental pollution.
Little systematic evaluation regarding the health risks determinants in urine and microbial treatment efficacy of urine nutrient recovery processes has been conducted. Source-separated urine contains excreted pharmaceuticals as well as fecal pathogens resulting from cross-contamination of collected urine with fecal matter. This presentation provides an overview of the VUNA project and specifically addresses the presence of human pathogens in urine storage tanks throughout Durban. The pathogen inactivation performance of urine nitrification moving bed biofilm reactors (MBBRs) that are used to produce a nitrogen- and phosphorous-rich fertilizer is further evaluated.
While urine diversion and nutrient recovery have typically been implemented as grassroots or community-driven initiatives, the magnitude of the UDDT installation in the eThekwini Municipality will allow an evaluation of the potential for urine nutrient recovery processes at scale. A hygiene evaluation is particularly important in such a large-scale urban or peri-urban setting in which urine storage times are reduced and fertilizer production rates are high.
Short biography:
Heather N. Bischel is Postdoctoral Researcher interested in safe and efficient reuse of water resources and sustainable sanitation to improve environmental and human health. As part of the Laboratory of Environmental Chemistry at EPFL and the VUNA project, she works in collaboration with the Swiss Federal Institute of Aquatic Science and Technology (Eawag), the eTheKwini Water and Sanitation (EWS) Municipality, and the University of Kwa-Zulu Natal (www.eawag.ch/vuna). VUNA aims to recover nutrients from urine in Durban, South Africa as part of a decentralized sanitation system that is affordable for the poor, produces a valuable fertilizer, and reduces environmental pollution. Previously, she worked at the US NSF Engineering Research Center for Re-inventing the Nation’s Urban Water Infrastructure (ReNUWIt) to address technological and management challenges associated with recycling wastewater for streamflow augmentation and ecosystem enhancement. Heather earned a Ph.D. and M.Sc. from the Environmental Engineering & Science Program at Stanford University (2011, 2007) and a B.S. in Civil and Environmental Engineering from the University of California, Berkeley (2005).
Practical information
- General public
- Free
- This event is internal
Organizer
- EESS - IIE
Contact
- Prof. Tamar Kohn, LCE