BIOLOGICAL AERATED FILTERS - ASSESSMENT OF THE PROCESS-BASED ON 12 SEWAGE-TREATMENT PLANTS

Biological aerated filtration is a recent and intensive process which has been greatly developed over the last few years. It is a technology based on biological processes with certain advantages, in particular the absence of secondary clarifiers, the modular nature and the wide variety of treatment applications. The monitoring of a dozen medium capacity (7,500 to 150,000 p.e.) plants designed to treat organic pollution, has enabled us to evaluate the process and its performance. The results obtained show that at applied loads of less than 7 kg of COD, the effluent is of satisfactory quality (<90 mg / 1 of COD) and that the process has a high efficiency to remove suspended solids. Numerous other aspects have been studied and the data collected confirm the potential of this process, which nevertheless requires a careful and regular system operation procedure.