We have heard many predictions about water shortages plaguing future generations, yet wasteful consumption continues. Researchers at the Fraunhofer Institute are not sitting idly by.
Construction is in progress for a housing estate with a unique water treatment scheme capable of collecting rainwater, purifying wastewater and even generating power. The project, dubbed DEUS 21 (DEcentralized Urban infrastructure System), connects 100 homes to a plumbing network and a specially designed building with equipment to process all the water and waste from the community. Researchers hope this pilot experiment will yield successful results and influence other communities to adopt the approach.
One of the key concepts is to eliminate wastefulness. A flush in conventional toilets uses 4 to 8 liters of water, but vacuum toilets need 1 liter or less per flush. The new approach includes vacuum toilets for all homes. A small building at the edge of the estate houses the vacuum station as well as the treatment systems. Domestic wastewater undergoes biological purification in a high-performance, anaerobic membrane plant. The wastewater components are converted into biogas, which provides heat and electricity for the community, and fertilizer for the land. Fortunately, no odor escapes from the containers because processing occurs in airtight conditions.
Kitchen biowaste is also processed and put to use. An appliance under the kitchen sink adds shredded food scraps to the wastewater outflow. Installation of the appliance increases the output of biogas, thereby creating more power for the home and keeping the energy bills low. No rainwater will be channeled into sewers. Instead, it will be collected in natural seepage pits on individual properties. The rainwater is stored in underground containers and fed into a modern membrane plant where it undergoes purification. It can then be used to wash clothes and dishes or water the garden.