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Operational optimisation

Vietnam: Waste water sludge treatment and reuse & Energy efficiency

Tilia June 24, 2018 No Comments

Since 2015, Tilia supports Vietnamese waste water municipal companies in optimising their operation, notably by enhancing the quality of sludge treatment and disposal and reducing the costs while making use of the nutrients contained in the sludge. 

  • The first step consisted in demonstrating that the waste water sludge was non-hazardous, and could therefore stop being handled as such to be used for agricultural purposes. Tilia carried out the corresponding analyses proving, on the one hand, that no hazardous substances were present (e.g. heavy metals), and, on the other hand, that the sludge had a sufficient concentration of nutrients to be used as a sustainable soil fertilizer.
  • After this, Tilia and its Vietnamese partners jointly started to develop an idea and the associated technical solution. In order to avoid complex operation procedures and high investments, it was decided to take a low-tech approach for the conversion/production of the sludge, partly developed by tilia through its own research. Known as “Terra Preta”, this approach allows a conversion and hygienisation of organic materials into a soil enhancer on the basis of anaerobic conditions. The technical design was complemented with a detailed economic analysis based on market prices to evaluate the market opportunities for such a sludge-based fertilizer, proving the business case for producing it.
  • As a result, it was decided to jointly start producing such a soil fertilizer derived from sewage sludge, whose use allows improving the local resource efficiency while integrating local partners in the initiative, ultimately creating value for the communities.

In parallel, Tilia is working on the energy efficiency enhancement of several waste water treatment plants, implementing measures concerning operational optimisation (e.g. optimising the O2 inlet towards treatment, also with remote operation support from Tilia staff based in Europe, pumps, etc.) and also self-production of energy through a photovoltaic plant with storage.


Vietnamese waste water municipal companies




Project Manager
Stefan Böttger
03:01:34 - 141.42 MB