Biofilm Carrier Discs (BFTS)

Within our corporate group, we have been providing the foamed carrier material, made of HDPE, for biofilm carriers for 12 years. The final manufacturing step of cutting and distribution was carried out by a well-known company in the market from 2010 to 2020. Meanwhile, we have integrated the complete manufacturing process, including the cutting of the biofilm carrier discs (BFTS), into our production process.

We completed the integration of the entire manufacturing processes in 2021 and have since offered our Biofilm Carrier Discs (BFTS) directly to our users. The production of the foamed carrier material, the processing of the material into round, parabolically curved discs, and sales are now handled by a single source, while maintaining the market-recognized quality.

Together with planning engineers, we support you in the areas of

  1. Design and Basic Engineering,
  2. Calculation of the required BFTS quantities

and adapt our biofilm carriers to your requirements. Through specific adjustments to the raw material formulation and manufacturing, it is possible to specifically influence the following aspects:

  1. Prevention of calcification,
  2. Promotion of bacterial growth,
  3. Adjustment of geometry (diameter, thickness), density, foam cell structure, and coloring.

Further information is also available on our website: www.biofilmtraeger.de

BFTS are used in biological water and wastewater treatment using the moving bed biofilm reactor (MBBR) process. Moving bed biology (MBBR), also known as fluidized bed biology or swirling bed biology, is a biological wastewater treatment process in which the microorganisms involved in degradation processes are immobilized on specially developed carrier material, where they ideally form a thin biofilm. The carrier material was specifically developed for nitrogen elimination but also shows very high conversion rates in the degradation of carbon compounds. This carrier material is used in both industrial and municipal biological wastewater treatment plants for nitrification, denitrification, and COD elimination (COD: chemical oxygen demand). Operating experience has shown that the COD elimination of the foamed carrier material exhibits a 10-fold higher degradation performance in direct comparison with conventional carrier material. In the nitrification stage, degradation rates of 4 to 5 kg NH4-N per m³ of carrier volume were achieved in small reactors.

The biofilm carrier is also increasingly used, for example, in ornamental fish farming, the wood-based materials industry, or the chemical industry.

The method of immobilizing microorganisms on the surface of the carrier material is of particular importance. The effectiveness of biological conversion is largely determined by the active surface area of the carrier. Here, the carrier material must have a sufficiently protected surface so that microorganisms can adhere and multiply in these areas. At the same time, maximum mass transfer between the microorganisms and the wastewater must be ensured.
Our thin and largely open carrier has a high surface area where microorganisms can settle in protected pores while still remaining in contact with the surrounding wastewater. This ensures optimal nutrient supply to the microorganisms and efficient removal of metabolic products, which explains the effectiveness and high degradation performance (the active surface area of the BFTS is approximately 4,500 – 5,500 m²/m³). The special geometry of the carrier material makes it possible to intensify the hydraulic shear forces acting on the surface and initiate a self-cleaning process, which constantly renews the active surface of the carrier. This effectively prevents the limitation of biological performance due to mass transfer resistances, e.g., by an excessively thick biofilm. In addition, the parabolic shape creates a high degree of turbulence in the flow, which enhances mass transfer. At the same time, the mobility of individual carriers within the entire quantity of BFTS is effectively increased, and a homogeneous distribution of the carrier material is achieved.

Other carrier materials, such as cylindrical floating bodies with internal chambers, have the disadvantage of having a smaller active surface area, and the relatively large interstices either become overgrown with biomass, thus hindering the supply of nutrients and oxygen, or merely occupy volume. Compared to other manufacturers of disc- or chip-shaped carrier materials, our BFTS carrier material offers the advantages of a more uniform pore distribution, a protective outer ring, and a plastic density > 1 g/cm³. As a result, the BFTS sink more easily, and complete mixing is achieved faster; the time required for commissioning is shortened. With our circular, foamed, HDPE BFTS, microorganisms find an ideal habitat. With an active surface area of approx. 4,500 – 5,500 m²/m³, optimal cultivation of microorganisms is achieved, and the highest volumetric conversion rates available on the market are attained. We can offer our BFTS with a diameter of 25 to 35 mm, any thickness, and any color for the core and shell. The established and common standard product has a diameter of approx. 30 mm and a thickness of 1.1 – 1.2 mm and is now preferably offered and used in sky blue.