Urban water management

Water management – water resources management, safe water supply, sanitation, and wastewater treatment – is a global key challenge of the 21st century. Innovations in all sectors of water management are essential – in industrialized countries and especially for the developing world, in arid and semi-arid environments.

The Fraunhofer IGB has developed a toolbox of technical innovations for sustainable decentralized water management systems, which are embedded in holistic infrastructure concepts and combined with energy and waste management. These innovations can be adapted and combined to generate individually the most favorable solution for the specific needs of each country or region.

Application areas

The water infrastructure system designed by Fraunhofer IGB comprises technologies for the cost-effective and efficient management of water in urban structures through the semi-decentralized treatment of water and wastewater streams. Systems solutions are available for future-oriented municipal water management in rural regions, for newly developed areas, urban districts in need of modernization and also for holiday resorts, tourist centers and hotel complexes. The system is especially effective for regions with no previous water infrastructure, lacking sewage networks and central sewage treatment plants. The concept is also ideal for areas where old types of infrastructure can no longer be adapted to cope with new challenges arising from climate changes or population increases/decreases.

Combined water-, waste-, and energy management

In combination with sustainable waste management concepts, energy from regenerative sources and innovative building services engineering, the concept is a holistic solution for a self-sufficient water supply infrastructure which is completely independent of central water supplies and wastewater disposal networks.

Semi-decentralized water management

The DEUS 21 water management concept, already operating on a demonstration scale in Heidelberg-Neurott and Knittlingen, is especially suitable for export to areas suffering from water-shortage as it can be adapted specifically to the requirements of arid and semi-arid regions.

Saving water and costs

Industrialized nations are used to wasting good drinking water although it would be relatively easy for each household to save this precious resource by installing appropriate faucets and toilets. Vacuum and pressure systems are excellent alternatives to conventional gravity sewers. Flushing toilets could be replaced by vacuum toilets, already common on airplanes, ships and trains and also in some Scandinavian households.

Use of rainwater

There is no need to use good drinking water for such activities as watering flowers in the garden or flushing a toilet. Especially in regions where water is scarce, it is well worth-while for each household to use rainwater and treated washing water for personal requirements. The Fraunhofer IGB has developed appropriate technologies to treat rainwater for subsequent use in households.

Anaerobic wastewater treatment

Anaerobic biotechnology, where organic carbon compounds are converted into biogas, i.e. a mixture of carbon dioxide and methane, is an attractive alternative to today's common aerobic wastewater purification treatment especially for decentralized or semi-decentralized water infrastructure systems. Biogas can be used as a regenerative energy carrier for running combined heat and power plants or, alternatively, can be fed into the existing natural gas network. Just like natural gas, biomethane can also be purified for use as fuel for automobiles.

Nitrogen and phosphorus compounds remain in the purified water and residual solids after anaerobic wastewater purification in enclosed bioreactors, which is not the case in the conventional, aerobic activated sludge process. Microorganisms are removed by microfiltration with a rotating disk filter. This treatment supplies water that is hygienic and safe to use for irrigating agricultural land, economizing on both clean water and fertilizers. Alternatively, the nutrients can be recovered from the purified water for fertilizing purposes. In this case, the water can then be discharged into the environment or reused.

Successful paradigm shift
Biogas and fertilizer from purified wastewater – Service water from rainwater