title: Modeling nitrogen removal for a denitrification biofilter.
abstract: Nitrous oxide (N2O) is a major greenhouse gas, heavily contributing to global warming. N2O is emitted from various sources such as wastewater treatment plants, during the nitrification and denitrification steps. ASM models, which are commonly used in wastewater treatment, usually consider denitrification as a one-step process (NO3- directly reduced to N2) and are as such unable to provide values for intermediate products of the reaction like N2O. In this study, a slightly modified ASM1 model was implemented in the GPS-X software to simulate the concentration of such intermediate products (NO2-, NO and N2O) and to estimate the amounts of gaseous N2O emitted by the denitrification stage (12 biofilters) of the Seine-Centre WWTP (SIAAP, Paris). Simulations running on a 1-year period have shown good agreements with measured effluent data for nitrate and nitrite. The calculated mean value for emitted N2O is 4.95 kgN-N2O/day, which stands in the typical range of estimated experimental values of 4-31 kgN-N2O/day. Nitrous oxide emissions are usually not measured on WWTPs and so, as obtained results show, there is a certain potential for using models that quantify those emissions using traditionally measured influent data.
authors.affiliation: Département de génie civil et génie des eaux, Université Laval, 1065 avenue de la Médecine, Quebec, G1V 0A6, Canada.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Samie
authors.forename: Jean
authors.initials: J
authors.lastname: Bernier
authors.forename: Vincent
authors.initials: V
authors.lastname: Rocher
authors.forename: Paul
authors.initials: P
authors.lastname: Lessard
mesh_terms: D003198:Computer Simulation; D058440:Denitrification; D008956:Models, Chemical; D009566:Nitrates / Q000737:chemistry; D009573:Nitrites / Q000737:chemistry; D009584:Nitrogen / Q000737:chemistry; D009589:Nitrogen Oxides / Q000032:analysis* / Q000737:chemistry; D010297:Paris; D012984:Software; D014865:Waste Disposal, Fluid / Q000379:methods; D018508:Water Purification / Q000379:methods
chemical_list: D009566:Nitrates; D009573:Nitrites; D009589:Nitrogen Oxides; D009584:Nitrogen