title: Comparison of dissolved-organic-carbon residuals from air- and pure-oxygen-activated-sludge sequencing-batch reactors.
abstract: Literature shows that full-scale pure-oxygen activated sludge (O2-AS) wastewater treatment plants (WWTPs) generate effluents with higher dissolved-organic carbon (DOC) concentrations and larger high-molecular-weight fractions compared to air-activated-sludge (Air-AS) WWTP effluents. The purpose of this paper was to evaluate how gas supplied (air vs. pure oxygen) to sequencing-batch reactors affected DOC transformations. The main conclusions of this paper are (a) O2-AS effluent DOC is more refractory than air-AS effluent DOC; and (b) O2-AS systems may have higher five-day biochemical oxygen demand removals than air-AS systems; however, in terms of COD and DOC removal, air-AS systems are better than O2-AS systems. Analysis of a database from side-by-side O2- and air-AS pilot tests from literature supported these observations.
authors.affiliation: Centro Interamericano de Recursos del Agua, Universidad Autónoma del Estado de México, Toluca. marioesparza@uaemex.mx
authors.forename: Mario
authors.initials: M
authors.lastname: Esparza-Soto
authors.forename: Peter
authors.initials: P
authors.lastname: Fox
authors.forename: Paul
authors.initials: P
authors.lastname: Westerhoff
mesh_terms: D000388:Air; D019149:Bioreactors; D002244:Carbon / Q000302:isolation & purification* / Q000378:metabolism; D016208:Databases, Factual; D008970:Molecular Weight; D009930:Organic Chemicals / Q000302:isolation & purification* / Q000378:metabolism; D010100:Oxygen; D012722:Sewage / Q000737:chemistry / Q000382:microbiology*; D014865:Waste Disposal, Fluid / Q000379:methods; D018508:Water Purification / Q000379:methods
chemical_list: D009930:Organic Chemicals; D012722:Sewage; D002244:Carbon; D010100:Oxygen