title: Oxygen transfer in a full-depth biological aerated filter.
abstract: The City of San Diego, California, evaluated the performance capabilities of biological aerated filters (BAFs) at the Point Loma Wastewater Treatment Plant. The City conducted a 1-year pilot-plant evaluation of BAF technology supplied by two BAF manufacturers. This paper reports on the first independent oxygen-transfer test of BAFs at full depth using the offgas method. The tests showed process-water oxygen-transfer efficiencies of 1.6 to 5.8%/m (0.5 to 1.8%/ft) and 3.9 to 7.9%/m (1.2 to 2.4%/ft) for the two different pilot plants, at their nominal design conditions. Mass balances using chemical oxygen demand and dissolved organic carbon corroborated the transfer rates. Rates are higher than expected from fine-pore diffusers for similar process conditions and depths and clean-water conditions for the same column and are mostly attributed to extended bubble retention time resulting from interactions with the media and biofilm.
authors: Civil and Environmental Engineering Department, University of California, Los Angeles, USA.
authors: Michael K
authors: MK
authors: Stenstrom
authors: Diego
authors: D
authors: Rosso
authors: Henryk
authors: H
authors: Melcer
authors: Ron
authors: R
authors: Appleton
authors: Victor
authors: V
authors: Occiano
authors: Alan
authors: A
authors: Langworthy
authors: Pete
authors: P
authors: Wong
mesh_terms: D019149:Bioreactors; D005374:Filtration; D010100:Oxygen / Q000378:metabolism*; D010865:Pilot Projects; D014865:Waste Disposal, Fluid / Q000295:instrumentation*
chemical_list: D010100:Oxygen