Department Sanitation, Water and Solid Waste for Development

Partnership for Urban Resource Recovery (PURR)

Sandec is working in collaboration with the Hanoi University of Civil Engineering to evaluate the feasibility of treating faecal sludge through anaerobic digestion. This project focuses on the development of knowledge and reliable methods that ensure the appropriate design of faecal sludge treatment technologies.


Context and problematic:

One quarter of Vietnam's population lives in cities, and the urban population is expected to keep increasing by at least 1 million people annually. Currently, there is no faecal sludge management, despite the fact that about 80 to 90% of the urban households have septic tanks. An initial assessment conducted by PURR in 2013 in five cities revealed an urgent need for faecal sludge management. Indeed, large volumes of faecal sludge are currently discharged without control in the environment and fields, and this amount is expected to increase in the upcoming 5 to 15 years. This faecal sludge needs to be treated to avoid the spread of pathogenic organisms. The aim is to produce stable end-products that are not harmful to the environment, and that can be locally used.


This three years project aims to:

  1. Develop basic understanding of faecal sludge characteristics, sampling and laboratory methods to facilitate the design of faecal sludge treatment plants
  2. Evaluate and optimize the potential for anaerobic digestion of faecal sludge to produce safe-to-use end-products
  3. Assess local conditions influencing the selection of appropriate treatment technologies, considering the potential market demand for resource recovery

PURR has undertaken several field studies in Vietnam to assess the local context and its influence on the potential for anaerobic co-digestion and other treatment technologies. Several laboratory and bench-scale studies are being done in Switzerland and in Vietnam to optimize the configuration and operation of anaerobic digesters. Further field studies will be conducted to assess the resource recovery options, and to provide recommendations on the appropriate treatment of faecal sludge in Vietnam.


Official partner:

Hanoi University of Civil Engineering

Laboratoire de Biotechnologies Environnementales