Hamburg city drainage
| Hamburg city drainage
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| legal form | Institute of public right |
| founding | 1995 (1842) |
| Seat | Hamburg , Germany |
| management |
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| Number of employees | 1,142 (2012) |
| Branch | Water supply |
| Website | www.hamburgwasser.de |
The Hamburg water (HSE) is a company of waste water management.
It collects Hamburg's wastewater in underground channels (also called Siele in Hamburg) and sends it to the Köhlbrandhöft / Dradenau sewage treatment network for cleaning. The annual average is around 410,000 cubic meters per day.
In 2017, the company had 1,022 employees, divided into 613 salaried employees and 409 industrial employees. In December 2004 there were a total of 30 trainees in the company, 17 of them in training to become specialists in wastewater technology, 2 as IT specialists and 11 in the commercial area.
Hamburger Stadtentwässerung and Hamburger Wasserwerke have been part of the Hamburg Wasser group since January 1, 2006 .
Field of activity
The HSE is in the areas of water conservation and groundwater protection , wastewater discharge and treatment , sludge treatment and waste recycling business. HSE also offers these services to municipal clients, including transferring the overall task of waste water disposal to a municipality.
history
Hamburg's municipal drainage system has existed for around 160 years and on January 1st, 1995 it changed from an authority to a company.
After the great fire in May 1842 , the English engineer William Lindley was commissioned to build a sewer system in Hamburg.
Hamburg's inner-city sewer network - it is the oldest in continental Europe, only in England there was already a sewer system at the time - covers 943 kilometers. Its construction began in 1842 and was largely completed in 1910. These canals - called Siele in Hamburg - are up to 4.70 meters wide and 3.85 meters high. They still form the backbone of the inner-city sewer system today. It is geared towards the Hafenstrasse pumping station and includes more than 80 mixed water overflows.
From 1967 onwards, a second, deep sewer network, about 100 kilometers long, made up of collectors and transport sewers. The new network relieved the old system to such an extent that it has since been systematically examined, renewed and refurbished.
Since October 1999, sampling and analysis of discharges from industry and trade (the so-called indirect dischargers) has also been part of the range of tasks of the HSE laboratories.
Since the end of 2003, HSE has been disposing of the wastewater from around 65,000 residents of Buxtehude , Neu Wulmstorf and Apensen .
Since the installation of a new gas engine system in mid-2004, all of the digester gas produced at Köhlbrandhöft can be converted into electricity in an environmentally friendly way.
Sewage network
The HSE collects the wastewater from a catchment area of around 300 square kilometers in the sewer network with a total length of around 5,400 kilometers with 200,800 house connections.
In the HSE sewer cadastre, 5,600 km of its own and external sewer networks are technically and geodetically documented. The basis for this is a geodetically oriented information system. In this system, all network-relevant information is recorded and mapped in a spatial relationship to the city topography.
Mixing process
The length of the mixed water pool is approx. 1,200 km.
Within the mixed system, there are underground emergency valves in the vicinity of bodies of water, the so-called mixed water overflows, which largely prevent the roads from flooding in heavy rain.
Relief concepts
The transport centers Winterhude and Alsterdorf are the backbone of the Alster relief concept . In the event of heavy rain, these relieve the drainage net above. Shortly after the onset of rain, all of the dirt on the streets is flushed into the sewer, resulting in particularly dirty mixed water. It is precisely this water that is brought directly to the sewage treatment plant by the transport sewers. These transport destinations are not connected to any body of water along the entire route.
Another cornerstone of the Alster relief concept are six mixed water retention basins with a capacity between 7,000 and 25,000 cubic meters. They store the amount of water that the sewer system can no longer absorb in heavy rain. After the rain has ended, when the sewer network is able to absorb again, i.e. there is no longer any risk of overflow, the temporarily stored water is pumped back into the sewer network or drained off.
Two new retention basins will protect the Bergedorf city waters and the Bille from mixed water overflows from 2008.
Separation process
The pipe system for waste water is approx. 2,250 kilometers long, that for rainwater is approx. 1,700 kilometers. The rainwater from the paved areas is either seeped into the ground or discharged into a local body of water using the shortest possible flow path. The wastewater is completely led to the sewage treatment plant and cleaned there.
Pressure drainage
In the shallow drainage areas such as B. Vier- und Marschlande , Francop and Neuenfelde , the drainage of the wastewater from 6,965 house connections (2004) takes place via a pressure drainage system of approx. 200 km in length. There is no rain sewer system in these areas.
Sewage treatment plant
Wastewater treatment
In dry weather, the sewage inflow averages four to five cubic meters per second. An amount that can increase to up to 17 cubic meters per second in heavy rainfall. An annual average of around 150 million cubic meters of wastewater is treated in the Köhlbrandhöft / Dradenau sewage treatment network.
The Köhlbrandhöft sewage treatment plant forms the first purification stage with mechanical treatment, where almost a third of the pollutants contained is removed from the wastewater. The second purification stage is at the Dradenau sewage treatment plant. For this purpose, the pre-treated wastewater from Köhlbrandhöft is passed through a 2.3 km long connecting pipe at a depth of 80 m under the Köhlbrand and pumped up in the sewage treatment plant. In the aeration tank, the microorganisms present here naturally break down the carbon and nitrogen compounds contained in the wastewater . A lot of oxygen is required for these metabolic processes , which was initially introduced into the wastewater through large surface aerators with high energy expenditure . From 2008 the 16 aeration basins of the Dradenau sewage treatment plant were gradually converted to pressure aeration, which promises significant energy savings. This conversion was completed in spring 2011, so that there are no more surface aerators at HSE.
The activated sludge is separated from the wastewater in the secondary clarifier, the second and last stage of the biological wastewater treatment. As return sludge, it is mixed with the mechanically pretreated wastewater and fed back into the aeration tank. The constant proliferation of the microorganisms creates a surplus of sludge, which is drawn off, pumped to the Köhlbrandhöft sewage treatment plant, thickened and given to the digestion towers . The treated wastewater is fed into the Köhlbrand. Up until then, the wastewater had spent between 7 and 30 hours, an average of 24 hours, in the sewage treatment plant network.
Sludge treatment and waste recycling
Around 3,600 cubic meters of sewage sludge are separated off during the various treatment steps for the wastewater. These are the primary sludge from mechanical and the excess sludge from biological wastewater treatment. Before the sewage sludge reaches the digestion towers , it is thickened by settling or centrifugation. In addition, over 100,000 tons of organic residues are accepted annually as part of external services at the Köhlbrandhöft sewage treatment plant and fed to the sludge or residue treatment.
Phosphorus is removed from wastewater by chemical precipitation . This is done by dosing iron salts prior to biological cleaning. The phosphate salts present in the wastewater form insoluble flakes that can be separated off together with the activated sludge.
The sludge water that occurs during sludge dewatering - also called centrate - accounts for around 30% of the nitrogen load in the inlet to the biological treatment, despite the relatively small volume flow. This partial flow is therefore treated biologically using the Store and Treat process specially developed by Hamburger Stadtentwässerung . In this way, around 1800 kg of nitrogen can be eliminated per day in the sewage treatment plant network.
Energy concept
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Including sewage sludge incineration, the sewage treatment plant network consumes around 115 million kilowatt hours of electrical energy annually .
The energy contained in the sewage sludge is used consistently. In a combined gas and steam turbine process from VERA sewage sludge incineration , around 72 million kilowatt hours of electricity and 74 million kilowatt hours of heat are generated. The power of two by 2010 production erected on the site of the treatment plant is completed Dradenau wind turbines of the type Nordex N100 / 2500 , which provide together approximately 14 million kWh of electrical energy per year. As a result, the in-house production rate of the sewage treatment plant network for electricity and heat is 100%.
Over the past few years, HSE has converted all 16 aeration basins to pressure aeration step by step. This means that a total of around 10,000 tons of CO 2 emissions can be avoided each year, with electricity savings of 17 million kilowatt hours.
Digestion towers
Ten digestion towers , each with a capacity of 8,000 cubic meters and 30 meters high, are an eye-catcher that can be seen from afar in the Port of Hamburg . Its formerly visible concrete cladding is now clad with silver-colored metal. Seven of the towers can be illuminated in different colors, and various motifs can also be projected onto the four front towers.
The sewage sludge rots here under constant circulation at a constant temperature of around 35 degrees Celsius. In the absence of air, i.e. anaerobic conditions, bacteria break down around 50% of the organic matter into methane , carbon dioxide and water. Water-soluble ammonium compounds are formed from organic nitrogen compounds. An average of 84,000 cubic meters of digester gas are generated per day , which are used in the VERA sewage sludge incinerator to generate electricity. Part of the gas is cleaned and fed into the Hamburg gas network.
laboratory
There are two laboratories available to Hamburg's municipal drainage system. These analyzes are necessary for the procedural control of the sewage treatment plants, for the monitoring and control of the treated wastewater and for the detection of poisonous and other prohibited substances that are discharged into the sewage network without permission. In the laboratories, the effluent values of the sewage treatment plants, in particular the biochemical oxygen demand and the chemical oxygen demand, are monitored.
Residues
Around 48 tons of ash remain as residual material per day , which is melted down and used as building material. A good six tons of gypsum are added from the flue gas cleaning , which is also used in the construction industry. The heavy metal sludge alone - 210 tonnes in 2004 - still has to be disposed of as hazardous waste .
New construction and renovation of sluices
In order to get an overview of the efficiency of a sewer network and to carry out dimensioning, the HSE can fall back on a wealth of experience of 25 years in hydrodynamic simulation calculations. With these calculation methods, the flow processes in the sewer system can be realistically mapped with the help of mathematical models and new construction and renovation measures can be planned economically.
Hamburger Stadtentwässerung uses various construction methods, whereby the effort, the costs and the local conditions determine the use of the respective construction technology or the process. The procedures used are:
- Open design
- Semi-open construction
- Underground construction
- Pipe lining
- Pipe relining
- Tunnel construction
- Directional drilling
Wherever possible and economically justifiable, the Hamburg municipal drainage system uses underground construction methods. More than 50% of the canal construction work in Hamburg is now carried out underground. This protects the environment and reduces the negative impact on residents from construction sites.
The sewer draft of the Hamburg municipal drainage system is certified according to DIN EN ISO 9001 : 2000 .
Current
Projects
The international project "Urban Water Cycle" (UWC) is funded by the EU regional fund and has been running since October 2004. The four UWC partners from Germany, the Netherlands, England and Denmark will investigate water management problems in metropolitan areas and develop solution strategies until 2007 . HSE and the authority for urban development and the environment oversee three sub-projects in Hamburg:
In the catchment areas of Mittlere Bille , Isebekkanal and Wandsbeker Gehölzgraben , different methods are being tested to improve the fresh water supply and reduce the pollution.
The sewage and sewer museum existed at the St. Pauli Landungsbrücken until March 2009 . In addition to historical cleaning equipment, employees of Hamburger Stadtentwässerung (HSE) salvaged the most astonishing objects - teeth, the fashion of the last decades, children's and shopping carts, even a wheelbarrow - from the wastewater floods and brought them together for an exhibition. At the confluence of two old sewers, wastewater could be experienced "live" and "sniffed".
literature
- Gerd Eich, Norbert Wierecky: From Hasenmoor to Transportsiel. 160 years of Hamburg city drainage , Hamburg city drainage, Hamburg 2002
- Ulrich Alexis Christiansen: Hamburg's dark worlds. The mysterious underground of the Hanseatic city. Ch.Links Verlag, Berlin 2008, ISBN 3-8615-3473-8
Web links
Individual evidence
- ↑ Annual Report 2012 ( Memento of the original dated October 4, 2013 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. (PDF; 2.1 MB)
- ↑ Status of wind energy use in Hamburg (PDF; 2.7 MB). Website of the Federal Wind Energy Association . Retrieved July 13, 2013.
