title: Formaldehyde biodegradation and its effect on the denitrification process.
abstract: Simultaneous formaldehyde biodegradation and denitrification in batch assays and in a continuous lab-scale reactor were studied. In batch assays, initial biodegradation rates between 0.7 and 3.3 g CKH2O g VSS(-1) d(-1) were obtained at formaldehyde concentrations between 300 and 2150 mg l(-1). The denitrification process was affected by the presence of formaldehyde. The nitrite accumulation increased with the initial formaldehyde concentration. In the continuous reactor, removal efficiencies above 98.5% were obtained at formaldehyde loading rates between 0.37 and 2.96 kg COD m(-3) d(-1) (625-5000 mg CH2O l(-1)). Formaldehyde removal led to the appearance of methanol and formic acid in the medium. Denitrification process was almost complete (around 99.7%) at nitrogen loading rates up to 0.44 kg N-NO3- m(-3) d(-1). Nitrite occasionally appeared in the effluent at concentrations less than 2.9 mg l(-1). The composition of the biogas indicated that denitrification and methanogenesis occurred simultaneously in the same unit.
authors.affiliation: Chemical Engineering Laboratory, Faculty of Sciences, University of A Coruña Alejandro de la Sota n 1, 15008-A Coruña, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Eiroa
authors.forename: A
authors.initials: A
authors.lastname: Vilar
authors.forename: C
authors.initials: C
authors.lastname: Kennes
authors.forename: M C
authors.initials: MC
authors.lastname: Veiga
mesh_terms: D019149:Bioreactors; D005557:Formaldehyde / Q000378:metabolism*; D007220:Industrial Waste; D009566:Nitrates / Q000378:metabolism*; D017680:Potassium Compounds / Q000378:metabolism*; D014865:Waste Disposal, Fluid; D014874:Water Pollutants, Chemical / Q000378:metabolism*
chemical_list: D007220:Industrial Waste; D009566:Nitrates; D017680:Potassium Compounds; D014874:Water Pollutants, Chemical; D005557:Formaldehyde; C023844:potassium nitrate