ABSTRACT
The development of high rate anaerobic bioreactors to treat industrial wastes in the past few years has focused on retention of the bacteria within the bioreactors. Fixed media, fluidized beds, granules and flocculated bacteria have been used in different anaerobic systems. 1 All of these systems seemed to have two phases, an attached phase and a dispersed phase. 2 The bacteria easily attached to each other as in activated sludge, but only became lightly attached to solid surfaces. A study by Canovas-Diaz and Howell 3 in 1986 indicated that a partially submerged, fixed media bioreactor gave better treatment than the system when it was completely submerged. It appeared that an anaerobic trickling filter might have potential in retaining the bacteria and for providing good contact between the wastewaters and the bacteria. For these reasons a laboratory study was performed to examine the characteristics of anaerobic trickling filters as a new type of anaerobic bioreactor for treating organic industrial wastewaters.
