Sustainable water management in urban areas:
During the past decades a most elaborated water management system has been developed and installed in cities and villages of the industrialized countries. Reliable supply of safe drinking water and advanced treatment of wastewater has been achieved. The »once-through« system which basically originates from the ancient Romans is not fully in line with the general concept of sustainable development, however, and implementation, operation and maintenance of the system in low-income countries is difficult.
In particular the layout of the sewer system requires high investments. To avoid sediment build-up and biogenic corrosion an enormous amount of tap water is needed – high quality water which is scarce in many parts of the world. To meet the Millennium Development Goals of the United Nations novel solutions are needed. Separate collection of the various wastewater fractions discharged from households, enterprises and industry, on site treatment and recovery of valuable substances for direct or indirect reuse are important measures to reduce the number of people who have not yet access to proper water supply and sanitation.