Themista results

A Themista installation increases the organic sludge degradation - and with this the energy yields - by 10% to 20%. Given the lab performance, affordable energy balance, simple and lower-developed costs, the payback time - depending on the local situation - will be 5 to 10 years.

Advantages of Themista

Compared to a WWTP with a traditional sludge digestion concept:

  • Enhanced biogas production (compared to traditional sludge digestion)
  • Improved energy balance compared to TPH
  • Lower total cost of ownership (lower construction and operational costs) compared to TPH
  • Lower use of chemicals (poly-electrolyte) for sludge thickening
  • Better dewaterability of the digested sludge
  • Smaller reactor, due to a higher sludge concentration in the reactors
  • No foam forming in the digester, resulting in a higher capacity of the reactor and reduced chemical usage (Antifoams)

‘Triple Helix’ partnership

The innovative sludge digestion technology Themista was developed by Royal HaskoningDHV in cooperation with STOWA (Foundation for Applied Water Research), Water board of Schieland and Krimpenerwaard. This project was co-financed with a contribution from the LIFE financial instrument of the European Union and with the Top Sector Energy subsidy from the Ministry of Economic Affairs.

To stimulate the innovation process of Ephyra®, the following parties have set up a ‘triple helix’ partnership: STOWA (Foundation for Applied WaterResearch), Waterboard Schieland en de Krimpenerwaard, Royal HaskoningDHV, TU Delft, Logisticon Water Treatment and Endress + Hauser.

The aim of this partnership is to gain knowledge and experience from joint (pilot) research. In 2016 we jointly realized the first practical installations.
The research program is financially supported by the Netherlands Enterprise Agency (RVO) and European Union (LIFE+).

The parties involved have consciously opted for cooperation within the ‘triple helix’ of government, knowledge organizations and the business community. This was very successful, for example, in the development of the Nereda® technology for waste water purification from the National Nereda Research Program (NNOP).


In recent years there has been an increasing attention for extracting more energy and raw materials from wastewater globally. This is underlined by the realisation of numerous wastewater treatment plants worldwide.

In addition, in 2015, governments worldwide agreed on Global goals, also known as the Sustainable Developments Goals (SDGs). The following goals for access to affordable and clean energy by 2030 have been formulated:

  • Ensure universal access to affordable, reliable and modern energy services
  • Increase significantly the share of renewable energy in the global energy mix
  • Double the global rate of improvement in energy efficiency
  • Enhance international cooperation to facilitate access to clean energy research and technology, including renewable energy, energy efficiency and advanced and cleaner fossil-fuel technology, and promote investment in energy infrastructure and clean energy technology
  • Expand infrastructure and upgrade technology for supplying modern and sustainable energy services for all in developing countries, in particular least developed countries, small island developing States, and land-locked developing countries, in accordance with their respective programmes of support

Themista contributes to the global sustainable energy goals. Also, it contributes to the reduction of waste from sewage treatment plants.

With the application of the Themista technology, water boards reduce the operational costs for wastewater treatment and the costs for sludge processing, while the biogas yields increase.