Sewage treatment plant

The wastewater from all Rodgau districts is treated at the wastewater treatment plant in Weiskirchen. The wastewater treatment plant has been continuously expanded and modernised since the end of the 1980s. It is state of the art.


For a clean environment and efficient cleaning, it is important that you as citizens behave correctly. This is because unauthorised waste and medication residues disposed of via the sewage system can cause damage both to the system and to nature!

  • What does not belong in waste water?

    Section 7 of the drainage regulations of the city of Rodgau lists what may not be discharged into the sewerage system. This prohibits the discharge of substances that:

    • clog the sewerage system
    • lead to deposits
    • form toxic, foul-smelling or explosive gases
    • Construction and materials
      (attack the sewerage system or impede wastewater treatment/sludge treatment)
      What are these?

    Overview

    Solid or liquid substances that do not belong in the sink or toiletWhat they doWhere they belong
    Ashis deposited, does not decomposeResidual waste containers
    Pads and nappiesclog pipework and pumpsResidual waste containers
    Chemicals (e.g. caustic soda, sulphuric acid)poison waste water, attack concrete pipesPollutant collection
    Colourspoison the waste waterPollutant collection
    Photographic chemicals (developer, fixer, etc.)poison the waste waterPollutant collection
    Deep-frying fatis deposited in the pipework, leads to blockagesCommercial: Disposal by specialised companies
    Household: Residues in sealed bags in residual waste containers
    Cat litteris deposited in the pipeworkIn the sealed bag in the residual waste container
    Lacquerspoison the waste waterPollutant collection
    Medicationpoison the waste waterPharmacy
    Engine oil and oily wastepoison the waste waterReturn to retailers in accordance with the Waste Oil Ordinance
    Plant protection productspoison the waste waterPollutant collection
    Cleaning agentpoison wastewater, corrode pipework and sealsPollutant collection
    Pest control agentspoison the waste waterPollutant collection
    Panty linerslead to blockagesResidual waste containers
    Cooking oils from householdslead to deposits and pipe blockagesIn a container in the residual waste bin
    Leftoverslead to blockages, attract ratsResidual waste containers
    Nappiesclog pipework and pumpsResidual waste containers

The wastewater is cleaned in various stages

1st stage: Mechanical cleaning

In the mechanical treatment process, undissolved substances are removed from the water via a screen, an aerated grit and grease trap and the primary clarifier, e.g:
  

  • Rags
  • Paper
  • Hygiene articles
  • Ear sticks
  • Vegetable scraps
  • Glass
  • Grit
  • Sand

2nd stage: Biological purification

In the next stage, the mechanically pre-cleaned wastewater undergoes intensive biological treatment.

  1. Soluble organic substances are treated with bacteria in "aeration tanks".
  2. The sludge containing bacteria is separated from the water in secondary clarifiers.
  3. The process water (wastewater from digested sludge dewatering) is treated in a separate small biology of a process water treatment plant.
  4. Here, over 90% of the ammonium load is removed from the wastewater from the digested sludge dewatering in the partial flow before it is then fed with a reduced load to the aeration tanks for further purification.

3rd stage: Dry cleaning

By adding precipitants, the phosphate contained in the wastewater is bound and thus eliminated.

Ecological utilisation of sewage sludge

The sludge separated in the secondary clarifiers is reused in the aeration tanks for wastewater treatment purposes.

  1. Excess sewage sludge is dewatered and pumped into the digestion towers.
  2. The sludge digestion process produces biogas, which is converted into heat and electrical energy in the company's own combined heat and power plant.
  3. The waste heat from the combined heat and power plant is in turn used to heat the digestion towers and buildings.
  4. The digested, dewatered sludge is disposed of purely thermally in mono-incineration plants.
  5. The water is then discharged back into the Rodau in a purified state.

Regular checks to protect the environment

Those responsible for the wastewater treatment plant ensure compliance with the prescribed discharge limits in their own operations. In addition, a commissioned laboratory monitors the purification performance of the wastewater treatment plant in accordance with the Self-Monitoring Ordinance (EKVO).

This is because the discharge of chemicals or other unauthorised substances into the sewerage system leads to

  • to wear and tear in the sewage treatment plant that drives up charges
  • also causes lasting damage to the environment

Ignorance does not protect against punishment. The drainage regulations of the city of Rodgau provide information on important provisions.


Tours of the sewage treatment plant

The wastewater treatment plant offers guided tours

  • for school classes
  • other interested groups

Simply call us to arrange an appointment at the contact address listed.