Optimization of Bed Material Height in a Submerged Biological Aerated Filter

Several years after beginning to study submerged biological aerated filters, the Environmental Technology and Environmental Microbiology Research Group (University of Granada, Spain) optimized the performance of this system, using a ceramic-based material bed. This material is generated by ceramic materials factories, as a waste product which is then grinded. Therefore, the use of this bed material maximizes the use of discarded material. A comparative study of height for the ceramicbased material bed, with regard to the TBOD5 and suspended solids parameters, is presented. For every bed material height, relations among volumetric loads applied and effluent concentrations are presented, as well as relations among hydraulic loads applied and effluent concentrations. Aiming for a maximum consumption value of 1.2 kg O2/kg TBOD5,eliminated, the air volume supplied was fixed. The real values obtained for this parameter are presented in relation to the TBOD5 volumetric load applied. The tests were performed at a pilot plant with full-scale height and a pilot scale cross-sectional area. The influent that was the primary effluent of a conventional treatment plant, was injected in the top of the filter, to create countercurrent flow.