Hamburg Water Cycle

The Hamburg Water Cycle (HWC) is a concept developed by Hamburg Wasser for holistic wastewater disposal and energy supply in urban areas. As with other innovative sanitary systems, the essential feature is the partial flow treatment, the separate collection and treatment of various partial flows of the wastewater. In contrast to conventional systems, where all of the domestic wastewater is channeled into the sewer system and is usually treated in a central sewage treatment plant , with the HWC the partial flows are treated semi-centrally, which enables new usage options and efficient treatment. The concept here is the fermentation of black water for biogas generation ago, the treatment of gray water with possibility of use as process water and a natural and local management of rainwater . The HWC aims to provide energy-efficient wastewater treatment and is suitable for use in cities around the world.

background

Against the background of the global shortage of phosphorus and drinking water and other challenges such as drug residues in wastewater as well as demographic changes in some countries such as Germany associated with decreasing flow in the sewer system, new ways of wastewater disposal are in demand.

As in most European cities, wastewater in Hamburg has so far been discharged and treated in a central system. In the Hanseatic city, wastewater is channeled through a 5000-kilometer-long sewage network to the Köhlbrandhöft / Dradenau sewage treatment network . On the way there, the various wastewater flows and rainwater are partly discharged together in a so-called mixed sewer system. However, this has some disadvantages, so it is possible that the volumes of water to be treated exceed the capacities of the canals and the sewage treatment plant in the event of high amounts of precipitation and that wastewater has to be released into nature untreated. On the other hand, the mixture of black water (waste water) , yellow water , gray water , industrial waste water and rainwater requires more complex water treatment . In addition, the recovery of nutrients is as nitrogen and phosphorus from the toilet water contained therein and the elimination of micropollutants considerably more difficult due to the dilution effect.

Circular-oriented systems for wastewater management and sanitation (Ecosan) form a novel approach within urban water management that is already being used several times in rural regions, especially in developing countries. Hamburg Wasser developed the Hamburg Water Cycle in order to transfer this approach and its advantages into an urban concept without sacrificing comfort for the user .

The concept

The general aim of the new drainage concept is no longer just to treat, but also to recycle. The use of the wastewater is adapted to the specific properties of black, gray and rainwater in order to achieve the most efficient and ecologically profitable results possible. This includes installations in buildings, a vacuum network, logistics and the specific treatment technology for the various wastewater flows.

Black water treatment

Due to its relatively high concentration of organic substances ( faeces and toilet paper), black water is suitable for anaerobic fermentation and the production of biogas. Subsequently, energy in the form of heat and electricity can be generated from the biogas by means of a combined heat and power system (e.g. combined heat and power plant ), thus avoiding energy-intensive cleaning of the wastewater. After the anaerobic treatment, the digestate can be used for soil improvement or fertilization.

The less diluted the black water can be obtained, the more efficient the energy generation becomes. Therefore, the black water is consistently kept separate from the gray and rain water. To further concentrate the black water, the HWC concept includes the use of water-saving toilets. A convincing alternative is, for example, the vacuum toilet in combination with a vacuum drainage . These toilets only use around one liter of water per flush and thus save around five to nine liters per flush compared to conventional flush toilets.

Gray water treatment

Compared to black water, gray water is polluted with only a few organic substances, is poor in nutrients and has only low bacterial concentrations and drug residues. Because of these properties, gray water is much easier and more energy-saving to clean than conventional waste water.

In the HWC, gray water is strictly separated from black water via a separate canal system. It is clarified in a specially designed system and can then be discharged into local receiving waters . Reuse as service water in the home is also conceivable, for example for watering the garden, use in washing machines or as toilet flushing water.

Rainwater harvesting

In many areas rainwater is drained together with the wastewater from households and industry in a so-called mixed sewer system. This can lead to the fact that the capacity of the sewer system is exhausted in the event of heavy precipitation, which leads to overflow and thus, in the case of mixed sewer systems, to the discharge of pollutants into the waters. The aim of the HWC, on the other hand, is to separate the wastewater flows and to manage the rainwater as close to nature as possible and on site. So the rainwater z. B. can be used for local uses such as green area irrigation or with the help of decentralized management methods in ponds are retained and evaporated, drained through hollows or discharged into nearby waters.

The measures of decentralized rainwater management improve the so-called microclimate and the formation of new groundwater . Another advantage is the relief of the canal system and the waters. The separation of the sewage flow has remarkable advantages with reference to the rainwater: The functions of a near-natural water cycle are strengthened, the flooding and flooding risk of the respective area are reduced and the drainage comfort is also maintained in the future.

Realizations

Gut Karlshöhe

Gut Karlshöhe is a 9-hectare environmental adventure park run by the Hamburg Climate Protection Foundation for educational purposes. After the fundamental renovation of the former stable building in 2011, Gut Karlshöhe will offer up to 140,000 people a year a comprehensive program of environmental education.

New environmental technologies are being used on the site and made available to visitors as objects to show. An essential component here is the drainage of the site, which is based on the Hamburg Water Cycle and at the same time represents the first demonstration system. In theory and practice, the way in which the new type of drainage can develop is shown. The plant-based sewage treatment plant for gray water purification that is located on the site is particularly interesting , but also the use of rainwater, which is used for irrigation and as toilet flushing water. Anaerobic treatment of the black water is not carried out due to the small amount of toilet waste water produced. This demonstration project was funded by the German Federal Environment Foundation (DBU) .

Jenfelder Au

In the Hamburg district of Wandsbek , the HWC has been implemented on a larger scale for the first time since 2012. The “Jenfelder Au” project was chosen as the IBA Hamburg reference project . Residential units for around 2,000 new residents will be built on around 35 hectares of a former barracks site. Climate-neutral living and sustainable drainage are made possible there as part of the HWC. With a total of around 630 residential units connected to the Hamburg Water Cycle, Jenfelder Au will be the largest residential area in Europe that uses a drainage system that separates part of the current. As a reference project of the IBA, it is gaining in importance, especially against the background of the IBA's guiding theme City in Climate Change : By extracting "green" energy from "black" wastewater, it helps to transform the vision of an energy-self-sufficient district into reality thus also significantly reducing CO ₂ emissions.

The implementation of the HWC is funded by the EU as part of the LIFE + program . In addition, this project is accompanied by the joint research project KREIS, which is supported by funds from the BMBF . Energy optimization is the core topic of an accompanying project funded by the BMWi .

Prizes and awards

In 2013 the Hamburg Water Cycle was awarded the VKU Innovation Prize. In the same year, the construction and research project around the Jenfelder Au was one of the winners in the BMBF's “Excellent Places in the Land of Ideas” competition.

literature

• Thomas Giese, Jörg Londong Coupling of regenerative energy generation with innovative urban drainage. Synthesis report on the research project KREIS Volume 30 of the series of publications of the Bauhaus Institute for Future-Oriented Infrastructure Systems (b.is). 16th year 2015
• Maika Wuttke lighthouse project of urban drainage ENTSORGA-Magazin 06-07 / 2015, pp. 48–50

Web links

• Hamburg Water Cycle (Official Website)
• District - supply through disposal
• Gut Karlshöhe
• Hamburg water

Individual evidence

1. ↑ D. Cordell, J.-O. Drangert, S. White: The story of phosphorus: Global food security and food for thought. Global Environmental Change 19 (2009), pp. 292-305
2. ↑ Frank R. Rijsberman: Water scarcity, Fact or fiction? Agricultural Water Management, Volume 80, Issues 1–3, February 24, 2006, pp. 5–22, ISSN  0378-3774 , 10.1016 / j.agwat.2005.07.001.
3. ^ Paul E. Stackelberg, Edward T. Furlong, Michael T. Meyer, Steven D. Zaugg, Alden K Henderson, Dori B Reissman, Persistence of pharmaceutical compounds and other organic wastewater contaminants in a conventional drinking-water-treatment plant . In: Science of the Total Environment , Volume 329, Issues 1-3, August 15, 2004, pp. 99-113, doi : 10.1016 / j.scitotenv.2004.03.015 .
4. ^ T. Hillenbrand, J. Niederste-Hollenberg, E. Menger-Krug, S. Klug, R. Holländer, S. Lautenschläger, S. Geyler: Demographic change as a challenge for securing and developing a wastewater infrastructure that is efficient in terms of costs and resources . (2010)
5. ↑ M. Oldenburg, R. Otterpohl: Possibilities of decentralized and semi-centralized wastewater treatment . Series of publications on water research (1997)
6. ^ S. Rüd, E. v. Münch: Ecological Sanitation: Selected example projects from Sub-Saharan Africa, Asia and Europe. International Conference Pathways towards Sustainable Sanitation in Africa, 2008
7. ↑ R. Ingle, E. v. Münch: Compilation of 27 case studies on sustainable sanitation projects from Sub-Sahara Africa. Sustainable Sanitation Alliance (SuSanA) and GIZ, 2011
8. ↑ Claudia Wendland: Anaerobic digestion of blackwater and kitchen refuse . Hamburg Reports on Urban Water Management 66th Technical Univ. Hamburg-Harburg 2008
9. ↑ M. Oldenburg, A. Albold, C. Wendland, R. Otterpohl: Experiences from the operation of a new sanitary concept over a period of eight years, 2008
10. ^ Association of Municipal Enterprises: Innovation Awards awarded wwt, December 9, 2013
11. ↑ HAMBURG WATER Cycle® in Jenfelder Au ( Memento of the original from February 14, 2016 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice.