High Rate Biological Sewage Treatment

EfloSAF is a biological treatment process based on submerged aerated biofilter using a fixed film and attached biological growth process. It is designed to achieve a final effluent of 10/10/2 in terms of BOD5/TSS/N-NH3. The high rate biological oxidation process is performed using an extremely efficient Submerged Aerated Filter with a very high specific surface area.

The flow of raw sewage to a treated final effluent is as follows:

  1. Raw sewage is lifted by a pump at average flow rate and delivered to a primary settling tank
  2. The settled sewage passes to the Biozone Submerged Aerated Filter
  3. Biologically treated liquor discharges from the Biozone to settlement
  4. Biologically treated liquor passes by gravity through the Final Settlement Tank
  5. Effluent discharges from settlement tank to a chlorination
  6. Final effluent is filtered via pressure sand filters prior to discharge or reuse


  • Small foot print
  • Low sludge production
  • No moving parts
  • High efficiency
  • Stable high quality effluent of 10 BOD and 10 TSS