Suspended Growth Systems

In this type of treatment plants the biomass is floating in suspension in the reactor. The air can be supplied by mixing devices or by pneumatic means (compressors); both aeration systems also maintain the biomass in suspension. The biomass is returned (recirculated) from the sedimentation tank to the reactor by means of a pump. An Illustration is shown on Figure 11. The figure shows three aeration chambers in sequence, followed by the sedimentation tank. The treated effluent is discharged at the top of the tank. At its bottom, there are pumps or ejectors for sludge recirculation and discharge of excess sludge. The aeration system is with diffusers and compressed air (the compressor is shown at the top of the unit).

Figure 11 Suspended growth treatment system