Abstract

In aerated processes, the oxygen transfer was limited by the presence of the suspended matter as colloid and the dissolved matter, which might decrease the biological degradation effectiveness. In this publication, three series of tests were conducted to study possibilities to reduce these matters: bacterial adaptation which was conducted in a biological aerated filter, adsorption/biosorption conducted on a biological aerated filter with a biofilm of adapted bacteria and percolation in a bioreactor with a packed plastic media. All the tests carried out gave convincing results concerning turbidity and chemical oxygen demand, as parameters limiting the oxygen transfer for a better biodegradation. The advanced adaptation improved their elimination. So, all these treatment techniques could be used as pretreatment processes; in addition, they required very little energy, particularly adsorption/biosorption and percolation.

Key words: Pretreatment, purification, biological aerated filter, adsorption, biosorption, percolation, packed plastic media.