Wastewater cycle. Cascadic recycling of wastewater and organic residue streams in buildings.

Basic research is being conducted for a sustainable cycle-oriented system for the building-integrated recycling of wastewater and food waste. This includes nutrient recovery for a sustainable circulation system (production of plant fertiliser and biochar), electricity production to meet the demand (up to 15 %) of plus-energy buildings, as well as water recovery for irrigation of the building's own or urban greenery and for summer cooling.

Short Description

Running Time


Starting point / motivation

Our current sewage system is very well developed, but not a sustainable circulatory system. Nutrients that are brought into the wastewater via human excretions can no longer be returned to food production because there are already too many impurities in the sewage treatment plants.
As well, the energy content of the substances in the wastewater can not be used well due to the aerobic treatment in the sewage treatment plant. The sewage sludge is therefore dried, burned and the ash, among other things, is landfilled. The food waste from households is mainly disposed of in the residual waste and is also incinerated, which means that the nutrients it contains are lost.

Contents and goals

Building on previous projects (e.g. KREIS in Hamburg) and through the use, expansion and combination of new components and processes and with laboratory tests, a new, innovative material and energy cycle system is to be tested and a demo project is to be prepared.


  • The long-term behavior of the new urine separation toilet (winner of the international competition "Reinventing the Toilet") and the separation of flushing water and solids are investigated experimentally and empirically.
  • Plant fertilizers and industrial water are recovered from urine and digested sludge water. Here, the Eawag urine recycling process is expanded to include nutrient recovery from digestate water and is tested in order to recover nutrients from this fraction as well.
  • Recording and optimization of the separation of medicaments, drugs and hormone residues also from the digestate water.
  • The high-temperature fermentation and biogas production of faeces and food waste is optimized through research and the minimum volume is determined. In addition, the hygiene, the procedural robustness of incorrect throws and discharged household chemicals are checked.
  • The biogas obtained is analyzed according to time, quality and quantity and the electricity and heat potential is calculated via fuel cells or microturbines.
  • Concepts for the use of leftover food from households are examined in terms of process engineering and construction.
  • User acceptance and user preferences are analyzed.
  • Concepts for the use of sewage sludge via carbonization processes and phosphate recovery are analyzed and evaluated.

Expected results

This planned project is intended to enable an economically and ecologically sustainable recycling of building wastewater and household leftovers. In addition to scientific knowledge, realistic and quickly multipliable application examples for the technology and the cycle products are to be created.

Project Partners

Project management

  • Schöberl & Pöll GmbH

Project or cooperation partners

  • AAT - Abwasser- und Abfalltechnik GmbH
  • BOKU Wien, Institut für Umweltbiotechnologie, Institut für Verfahrens- und Energietechnik
  • Eawag (Eidgenössische Anstalt für Wasserversorgung, Abwasserreinigung & Gewässerschutz
  • LAUFEN Austria AG
  • Dr. Alexander Keul – Umweltpsychologie, Angewandte Psychologie

Contact Address

Schöberl & Pöll GmbH
Lassallestraße 2/6-8, 1020 Wien
+43 1 726 45 66