Industrial applications of Biological Aerated Filters

Biological aerated filters (BAF's) are compact wastewater treatment reactors capable of achieving biological oxidation and solids removal in a single reactor. The basic principle of operation is that biomass grows on the surface of a submerged medium. Air is injected at or near the base of the medium. The effluent to be treated flows either upward or downward through the bed. Biological oxidation occurs during passage through the bed and suspended solids are retained within the bed. These solids are removed periodically by backwashing. The use of BAF technology is well known for treatment of municipal sewage. The application of this technology to industrial effluents is less well documented. In this paper the application of the TETRA ColOXTM BAF to treatment of effluents arising from paper making, from steel making, from plastics manufacture and from the electronics industry is described.