title: Nitrification-denitrification in waste stabilisation ponds: a mechanism for permanent nitrogen removal in maturation ponds.
abstract: A pilot-scale primary maturation pond was spiked with (15)N-labelled ammonia ((15)NH(4)Cl) and (15)N-labelled nitrite (Na(15)NO(2)), in order to improve current understanding of the dynamics of inorganic nitrogen transformations and removal in WSP systems. Stable isotope analysis of delta(15)N showed that nitrification could be considered as an intermediate step in WSP, which is masked by simultaneous denitrification, under conditions of low algal activity. Molecular microbiology analysis showed that denitrification can be considered a feasible mechanism for permanent nitrogen removal in WSP, which may be supported either by ammonia-oxidising bacteria (AOB) or by methanotrophs, in addition to nitrite-oxidising bacteria (NOB). However, the relative supremacy of the denitrification process over other nitrogen removal mechanisms (e.g., biological uptake) depends upon phytoplanktonic activity.
authors.affiliation: Sección de Saneamiento Ambiental, Universidad Nacional de Colombia, Bogotá, Colombia. macamargov@unal.edu.co
authors.forename: M A
authors.initials: MA
authors.lastname: Camargo Valero
authors.forename: L F
authors.initials: LF
authors.lastname: Read
authors.forename: D D
authors.initials: DD
authors.lastname: Mara
authors.forename: R J
authors.initials: RJ
authors.lastname: Newton
authors.forename: T P
authors.initials: TP
authors.lastname: Curtis
authors.forename: R J
authors.initials: RJ
authors.lastname: Davenport
mesh_terms: D000641:Ammonia / Q000737:chemistry; D001419:Bacteria / Q000378:metabolism; D018533:Biomass; D056890:Eukaryota / Q000378:metabolism; D009573:Nitrites / Q000737:chemistry; D009584:Nitrogen / Q000737:chemistry / Q000378:metabolism*; D009587:Nitrogen Isotopes / Q000737:chemistry; D010839:Phytoplankton / Q000378:metabolism*; D012621:Seasons; D012722:Sewage / Q000032:analysis*; D013696:Temperature; D014865:Waste Disposal, Fluid / Q000379:methods*; D014871:Water Microbiology; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*; D018508:Water Purification / Q000379:methods*
chemical_list: D009573:Nitrites; D009587:Nitrogen Isotopes; D012722:Sewage; D014874:Water Pollutants, Chemical; D000641:Ammonia; D009584:Nitrogen