Carrier retention sieve

The use of a retention system (retention sieve) that prevents the carriers within the biological reactor from being forwarded to discharge and dispersed into the environment is perhaps the most critical aspect in sizing a plant design with attached biomass on moving media.

When speaking of construction preferences, we prefer the adoption of completely submerged horizontal cylindrical sieves made of stainless steel that can guarantee a limited pressure drop and at the same time ensure easier cleaning than more traditional vertical grids.

Thanks to a timed air cleaning system placed under each sieve and connected to the main air manifold for the biological process, it is possible to generate a localized turbulence that promotes cleaning by hindering the adhesion and the sieve’ clogging due to organic biomass.

The variables that need to be considered when choosing the retention sieve system are:

  • Number and orientation in the tank
  • Cylindrical diameter and length
  • Diameter and density of the passage holes
  • Sustainable hydraulic flow
  • Pressure drops generated