Wastewater Association Braunschweig

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Logo of the wastewater association

The Abwasserverband Braunschweig is a water and soil association based on the Water Association Act of 1991 and thus a corporation under public law .

history

The biological wastewater utilization began in Braunschweig in 1894 with the construction of the sewage fields at the Steinhof monastery (soil filtration), which is located north of the city. The area covers around 460 hectares and can hold 10,000 cubic meters of wastewater per day. The population of Braunschweig at that time was 100,000.

However, as the number of inhabitants in Braunschweig continued to rise, the sewage fields were no longer sufficient to absorb and purify all of the wastewater. Because of this and a measure taken by the federal and state governments to keep public waters clean, the city of Braunschweig needed a new organizational structure with regard to wastewater recycling. The result was the founding of the Braunschweig wastewater association in 1954.

In 1979, a pretreatment plant with mechanical and biological cleaning was put into operation in the Steinhof sewage treatment plant . This reduced the unpleasant smell to a minimum. Up to 1991 the expansion to a fully biological sewage treatment plant took place. In 2000, the sewage treatment plant was supplemented by sludge digestion.

In 1990 the sewage fields were also converted for biological post-treatment. In 1991 the "meander system" was introduced as a new cleaning process in the trickle operation.

In 2007, the wastewater association built a biogas plant in Hillerse to convert the energy crops that grow in the rainwater area into biogas.

Tasks of the association

Rain

The wastewater from the city of Braunschweig and some municipalities of the Gifhorn water association is mechanically and biologically cleaned in a multi-stage process in the Steinhof sewage works . This treated wastewater is rained together with nutrient-rich sewage sludge on the agricultural areas of the association members. Renewable raw materials such as maize and rye are grown on a good third of this area . These are converted into biogas in the Hillerse biogas plant , which is mainly used by BS Energy to generate electricity and heat for the city of Braunschweig.

Main tasks

Association area

The entire area managed by the Abwasserverband Braunschweig is around 4,300 hectares, of which 2,700 hectares are used as irrigation areas. In addition to the areas of the city of Braunschweig , this also includes parts of the districts of Gifhorn and Peine .

Brunswick model

The Braunschweig model is a water-nutrient-energy cycle. It was developed by the Braunschweig wastewater association.

  • Sewer network: The cycle begins in the sewer network. The wastewater from 290,000 inhabitants of the city of Braunschweig and some communities of the Gifhorn water association flows through the sewer network to the Steinhof sewage treatment plant.
  • Steinhof sewage treatment plant: The wastewater is mechanically and biologically treated in a multi-stage process. Sewage sludge is produced during this process. This is used as fertilizer on agricultural land.
  • Sewage fields: 1/3 of the fully biologically treated wastewater, around 7 million cubic meters per year, is discharged from the Steinhof sewage treatment plant into the Braunschweig sewage fields .
  • Rainfall: The remaining 2/3 of the treated wastewater is rained on the agriculturally used areas of the association area. A negative climatic water balance and the low water retention capacity of the soil are the reasons for this irrigation. During the growing season, the treated wastewater is enriched with nutrient-rich sewage sludge.
  • Hillerse biogas plant: Renewable raw materials such as maize and rye are grown on around 1/3 of the association's area, which are first converted into biogas and later into electrical energy in the biogas plant. 20% of the biogas is converted into electricity directly in the Hillerse biogas plant. The remaining part is transported to Braunschweig via an underground gas pipeline and converted into electricity and heat by BS | ENERGY.
  • City of Braunschweig: The cycle closes in the city of Braunschweig. The energy generated in the Hillerse biogas plant supplies 6,000 to 7,000 Braunschweig households with electricity and 1,000 to 1,500 households with heat.

literature

  • Rolf Ahlers , Theodor Eggers: Abwasserverband Braunschweig: 50 years of successful activity for people and the environment through cleaning and agricultural recycling of municipal wastewater. Krebs, Wendeburg 2004, ISBN 3-932030-30-3 .

Web links

Individual evidence

  1. ↑ Association area on abwasserverband-bs.de
  2. ↑ The Braunschweig model on abwasserverband-bs.de