title: Evaluation of denitrification-nitrification biofilter systems in treating wastewater with low carbon: nitrogen ratios.
abstract: A two-stage biological aerated/anoxic filter (BAF) system for denitrification-nitrification was developed to increase nitrogen removal in the treatment of municipal wastewater with low carbon:nitrogen (C/N) ratio [Formula: see text]. This system exhibited a high denitrification efficiency (67%), despite the low C/N ratio, and the ratio of reduced nitrate to consumed organic compounds was greater than the theoretical value due to the minimization of the conversion of organic carbon to biomass growth, the maintenance of low levels of dissolved oxygen in recycled water, and the maximization of use of organic carbon biosorbed inside biomass in the denitrification BAF. The maximum rate of nitrogen removal was achieved at a recycle ratio of 170%, and the headloss in two BAFs was maintained after a 24-h backwash. Biological nitrogen removal in a two-stage BAF system was possible in a short hydraulic retention time (1.2 h) because the maximum reaction rates of nitrifiers and denitrifiers in each column were achieved.
authors.affiliation: a Environmental Engineering Department , Samsung Engineering Co., Ltd , 500 Samsung GEC, Sangil-Dong, Gangdong-Gu, Seoul 134-728 , Republic of Korea.
authors.forename: Seungjin
authors.initials: S
authors.lastname: Kim
authors.forename: Wookeun
authors.initials: W
authors.lastname: Bae
authors.forename: Moonil
authors.initials: M
authors.lastname: Kim
authors.forename: Jong-Oh
authors.initials: JO
authors.lastname: Kim
authors.forename: Jinwook
authors.initials: J
authors.lastname: Chung
mesh_terms: D058440:Denitrification; D005374:Filtration; D058465:Nitrification; D009584:Nitrogen / Q000302:isolation & purification*; D009930:Organic Chemicals; D010100:Oxygen; D018508:Water Purification
chemical_list: D009930:Organic Chemicals; D009584:Nitrogen; D010100:Oxygen
keywords: biological aerated/anoxic filter; carbon/nitrogen ratio; postnitrification; predenitrification