title: Respirometric evaluation of a mixture of organic chemicals with different biodegradation kinetics.
abstract: The study evaluated the biodegradation characteristics of a mixture of organics with different biodegradation characteristics in an integrated chemical plant effluent. The wastewater had a total chemical oxygen demand (COD) content of 12,800mg/L, mostly soluble and 93% biodegradable. The evaluation was based on respirometry, and mainly consisted on model calibration and interpretation of the oxygen uptake rate data, which exhibited an original and specific profile with a sequence of two peaks and three plateaus. A specific model was defined for this purpose, which identified four different biodegradable COD components with significantly different process kinetics. The major fraction accounting for 57% of the total biodegradable COD in the wastewater had to be hydrolyzed before biodegradation with a low hydrolysis rate of 1.3day(-1). The analysis of the experimental data showed that the oxygen utilization started with a delayed response after substrate addition. The delayed logarithmic phase could be characterized by a Haldane type of inhibition kinetics.
authors.affiliation: Istanbul Technical University, Faculty of Civil Engineering, Environmental Engineering Department, 34469 Maslak, Istanbul, Turkey. ubay@itu.edu.tr
authors.forename: Emine Ubay
authors.initials: EU
authors.lastname: Cokgor
authors.forename: Güçlü
authors.initials: G
authors.lastname: Insel
authors.forename: Egemen
authors.initials: E
authors.lastname: Aydin
authors.forename: Derin
authors.initials: D
authors.lastname: Orhon
mesh_terms: D001673:Biodegradation, Environmental; D007700:Kinetics; D008956:Models, Chemical; D009930:Organic Chemicals / Q000032:analysis* / Q000378:metabolism*; D010100:Oxygen / Q000032:analysis* / Q000378:metabolism*; D010101:Oxygen Consumption; D014865:Waste Disposal, Fluid; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism*
chemical_list: D009930:Organic Chemicals; D014874:Water Pollutants, Chemical; D010100:Oxygen