Cathleen Ascalic
Institute of Agricultural Technology

Bundesallee 47
38116 Braunschweig
Phone: +49 531 596 4102/ 4103
Fax: +49 531 596 4199

Recirculation air scrubbing of inside stable air


View of a typical fattening stable suitable for the planned project (c) Thünen-Institut
View of a typical fattening stable suitable for the planned project (© Thünen-Institut)

Internal elimination of ammonia and aerosols from the air in buildings for livestock using a Moving Bed Biofilm Reactor (MBBR)

With 95 % the agriculture is the main polluter of ammonia emissions in Germany.  A considerable portion of these emission is released from animal livestock. Emissions should be reduced and animal welfare improved as well by using the recirculation air scrubbing within the animal keeping.

Background and Objective

As one of the relevant air pollutants ammonia contributes to acidification and nutrient accumulation processes in surface and ground waters. Ammonia is also a precursor chemical for the nitrous oxide production which is a relevant greenhouse gas. Above that ammonia affects the animal health within keepings by mucous membrane irritations an affections of the respiratory tract. Germany heavily exceeds the Europe-wide concerted emission ceilings for ammonia. Therefore the ammonia emission needs to be reduced significantly.  Aim of the project is the developing of a process for ammonia and aerosol separation in the animal keeping using an inside located recirculation air scrubber. With the moving bed bio film reactor (MBBR) washed-out pollutants should be degraded. Aerosols as forage compounds should be oxidized in the bio film reactor to carbon dioxide, heat and water, while ammonia should be oxidized in the MBBR reactor to nitrate and transferred to atmospheric nitrogen if applicable.

Target Group

Livestock owners, pig farmers

Agriculture organizations, livestock stakeholders, organizations of chart Chambers    

Agriculture industry (process engineering, plastic material production)

Research and educational institutions


On the basis of practical data generated from pig keepings (trace gas concentrations, volume flows, temperature and humidity) a prototype consisting of an inside circulation scrubber and MBBR bio reactor is planned. After that the technical equipment and the process control will be defined. Construction and installation of the prototype will then be realized in a pig fattening stable. After this a scrubber performance test will be made in view of ammonia and aerosol separation at different volume flows and operation conditions. During the performance test of the MBBR bio reactor the nitrification rate at different aeration intensities and the production of reaction products are matter of particular interest. Required structural and procedural improvements will be implemented within the test phases. In further project steps it will be investigated how the process affects the indoor air quality and animal health. In addition operation costs and process stability should be assessed.

Our Research Questions

Is it possible to reduce ammonia and aerosol concentrations permanent in the inside stable air by using the MBBR bio reactor?

Which separation efficiencies can be secured with the system and how much volume of processing water accumulates?

To what extent the washing water from the bio reactor can be recycled for the ammonia separation in the scrubber unit?


Involved Thünen-Partners

Involved external Thünen-Partners

  • Kunststoff-Sranger GmbH
    (08525 Plauen, Deutschland)
  • Institut für Binnenfischerei e.V. Potsdam-Sacrow
    (Potsdam, Deutschland)

Funding Body

  • Landwirtschaftliche Rentenbank
    (national, privat)


9.2018 - 8.2021

More Information

Projekt type:
Project funding number: 100362952
Project status: ongoing