title: Nutrient content in sludge profiles from a full-scale stabilization pond in a temperate location.
abstract: The inorganic nutrient concentrations in sludge profiles from a full-scale municipal facultative pond in Puerto Madryn City (Argentina) were measured. Sludge samples were collected with cores during autumn, winter, and summer at three sites: inlet, intermediate, and outlet. In general, the sludge accumulates NH4+ and PO4(3-), increasing their concentrations with depth. However, NH4+ presented a different behavior at the outlet station during the summer, when the lower concentrations were recorded. This finding reflects a nutrient release, originating in their greater demand from the water column. In the sludge, the NO3- followed the spatial and seasonal pattern recorded in the surface water: detectable concentrations in the warmer months at the outlet. The vertical reduction of NO3- could be an indication of denitrification. The study supported the hypothesis that the sludge can act as a nutrient trap or source, depending on factors such as the temperature, nutrients/oxygen concentration, mixing processes, and location.
authors.forename: Mauricio
authors.initials: M
authors.lastname: Faleschini
authors.forename: José L
authors.initials: JL
authors.lastname: Esteves
mesh_terms: D064751:Ammonium Compounds / Q000737:chemistry; D002980:Climate; D009589:Nitrogen Oxides / Q000737:chemistry; D010710:Phosphates / Q000737:chemistry; D061005:Ponds; D012621:Seasons; D012722:Sewage / Q000737:chemistry*; D014865:Waste Disposal, Fluid / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D064751:Ammonium Compounds; D009589:Nitrogen Oxides; D010710:Phosphates; D012722:Sewage; D014874:Water Pollutants, Chemical