Human- and food waste consists of energy and valuable nutrients. The project’s Resource Factory makes use of this fact by transforming waste into valuable resources and sustainable energy.
All water-saving toilets and food grinders are connected to a separate vacuum sewage system. This combined waste is transported through smaller pipes using negative pressure created by vacuum pumps. Waste (biomass and a limited amount of water) are buffered in the vacuum station and subsequently delivered to the nearby resource factory.
If you want to have more information about vacuum sewage systems we recommend the Guideline document developed by Hamburg Wasser.
The resource factory is a digestor named “Upflow Anearobic Sludge Blanket Reactor” (UASB) that heats black water up to 35 degrees Celsius. During this process, biogas is withdrawn on the top of the digestor. This biogas can be converted into heat to keep the sludge on the same temperature. What remains are resources including nutrients such as nitrate and phosphate that can be used as fertilizers, which is further heated up to 70 degrees Celsius in order to remove all harmful bacteria and harmful substances.
The produced fertilizers will be tested in nearby green yards for non-food crops and horticulture production. This way, black waste water is directly treated on site, hence, less waste water needs to be transported to centralized services. Furthermore, it is directly transformed into valuable resources for developing green public spaces.