Stabilization of fecal substrates by lactic acid fermentation - FAEKASHI
In this research project we identify, describe and define stable boundary conditions for the lactate fermentation of human faeces from dry separation toilets during storage. Our overall goal is to develop a robust and user-oriented process for successful hygienization, handling and resource recovery from human faeces in the medium term. Ideally, the output of the fermentation process will be a product that meets all the requirements for stable lactate fermentation and can be produced worldwide using only local resources. All findings, as for example, relevant parameters of process operation and the formulation of the used additives, will be disclosed to the general public at the end of the project.
The project will also investigate the potential benefits and cost savings that can be realized through hygienized faeces for different areas of application. One focus is on open/pit latrines in Sierra Leone, which are to be replaced with dry separation toilet systems in the future, as these are responsible for the widespread contamination of groundwater close to the surface.
In our estimation, the project has a high environmental relief potential in the medium term with regard to water consumption when water-operated toilets are not used, hygienization and thus the protection of the adjacent surface waters, but also soil fertility in the event of further processing of the stabilized faeces into terra-pretta products.
Project partners:
- Helmholtz-Centre for Environmental Research (Coordination)
- Holzapfel und Konsorten KG
- Forikolo Action Group
- Wasser ohne Grenzen e.V.
- Steinbeis-Innovationszentrum Organismische Mykologie und Mikrobiologie
The project is funded by the Deutsche Bundesstiftung Umwelt (DBU) (AZ 37541/01).
News
February 2025 - First LAF experiments started in Sierra Leone
The first LAF experiments have been successfully launched by our project partner in Mathen, Sierra Leone. The experiments are being conducted at the Mathen Educational Center (MEC) by local staff and accompanied by employees of the UFZ and Forikolo e.V. In the experiments various locally available substrates are tested as sugar sources for the LAF. The objectives are primarily to test the experimental implementation on site and to train the technical staff to carry out further, more extensive experiments.
November 2024 - Elimination of E. coli by LAF was demonstrated
Recent results show the complete elimination of E. coli in human feces by lactate fermentation (LAF). The naturally occurring organisms in feces were reduced from 108 CFU/mL (colony forming units per milliliter) to zero CFU/mL within 7 days.
October 2024 - New Master's student joins the Faekashi team
We warmly welcome Lithiya James to our team. Lithiya is studying Molecular Biotechnology at Anhalt University of Applied Sciences. In scope of her master's thesis at the UFZ, she is investigating the degradation of pharmaceutical residues in human feces by lactate fermentation.
April 2024 - New member of the Faekashi team
We warmly welcome Marie Loidl to our team. Marie has been working at the UFZ since 1.4.2024 and is investigating nutrient sources for the growth of lactic acid-producing bacteria as well as their immobilization for the fermentation of human faeces as part of her bachelor thesis.
February 2024 - New findings on the buffering capacity of human faeces
The buffering capacity of a substrate indicates how much acid must be added to the substrate in order to lower the pH value to a certain level. The buffering capacity of human faeces was previously unknown and was investigated as part of the project work. This has provided important new insights:
Other than previously assumed the formation of higher lactic acid concentrations is required to achieve a pH reduction to 4, which is the target for hygienization. This has an influence on various process engineering parameters, including the quantity of additives to be added and the fermentation conditions.
October 2023 - Project Meeting in Weimar, Germany
On October 23, 2023, the Faekashi team visited Holzapfel und Konsorten KG. After discussing the initial results, various dry separation toilet systems were presented.
August 2023 - Preliminary trials started
Preliminary trials started at the end of August with the aim of testing the previously developed experimental apparatus and gaining initial experience with lactate fermentation.
July 2023 - Kick-off meeting
The first meeting of the Faekashi consortium took place on July 20, 2023. During the meeting, which took place online, the first steps in the project were discussed and the next (face-to-face) meetings were planned.