title: Comparison of oxygen-transfer measurement methods under process conditions.
abstract: The objective of this paper is to compare the following four methods of measuring oxygen transfer in wastewater treatment plants under process conditions: the offgas, hydrogen peroxide (H2O2), reaeration, and in situ oxygen uptake rate (OUR) methods. Comparative tests were performed under controlled conditions in a pilot column and in six full-scale oxidation ditches equipped with fine-bubble diffusers and slow-speed mixers. The offgas and H2O2 methods give similar results (differences between the oxygen-transfer coefficients under field conditions [k(L)a(f)] from each method lower than 10%). The reaeration procedure gives more random results (differences from -5 to -43% compared with values obtained using the offgas method). The in situ OUR method, in the presence of a horizontal flow of mixed liquor, leads to an estimate of k(L)a(f) to within 15% of the offgas value.
authors.affiliation: Water Quality and Hydrology Research Unit of the Cemagref, National Institute of Agricultural and Environmental Engineering Research, Antony, France.
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Capela
authors.forename: Sylvie
authors.initials: S
authors.lastname: Gillot
authors.forename: Alain
authors.initials: A
authors.lastname: Héduit
mesh_terms: D004784:Environmental Monitoring / Q000379:methods*; D006861:Hydrogen Peroxide / Q000737:chemistry; D016877:Oxidants / Q000737:chemistry; D010084:Oxidation-Reduction; D010100:Oxygen / Q000032:analysis*; D014865:Waste Disposal, Fluid / Q000379:methods*
chemical_list: D016877:Oxidants; D006861:Hydrogen Peroxide; D010100:Oxygen