title: Effect of dissolved oxygen and temperature on macromolecular composition and PHB storage of activated sludge.
abstract: The macromolecular composition of activated sludge (lipids, intracellular proteins and intracellular polysaccharides) was studied together with its capacity to store macromolecules such as polyhydroxybutyrate (PHB) in a conventional activated sludge system fed with synthetic sewage water at an organic load rate of 1.0 kg COD/(m(3)·d), varying the dissolved oxygen (DO) and temperature. Six DO concentrations (0.8, 1.0, 1.5, 2.0, 2.5 and 8 mg/L) were studied at 20°C with a sludge retention time (SRT) of 6 days. In addition, four temperatures (10ºC, 15ºC, 20ºC and 30ºC) were assessed at constant DO (2 mg/L) with 2 days SRT in a second experimental run. The highest lipid content in the activated sludge was 95.6 mg/g VSS, obtained at 30°C, 2 mg/L of DO and a SRT of 2 days. The highest content of intracellular proteins in the activated sludge was 87.8 mg/g VSS, obtained at 20°C, 8 mg/L of DO and a SRT of 6 days. The highest content of intracellular polysaccharides in the activated sludge was 76.6 mg/g VSS, which was achieved at 20°C, a SRT of 6 days and a wide range of DO. The activated sludge PHB storage was very low for all the conditions studied.
authors.affiliation: a Escuela de Ingeniería Bioquímica , Pontificia Universidad Católica de Valparaíso , Valparaíso , Chile.
authors.forename: Paula
authors.initials: P
authors.lastname: Reyes
authors.forename: Alejandra
authors.initials: A
authors.lastname: Urtubia
authors.forename: María C
authors.initials: MC
authors.lastname: Schiappacasse
authors.forename: Rolando
authors.initials: R
authors.lastname: Chamy
authors.forename: Silvio
authors.initials: S
authors.lastname: Montalvo
authors.forename: Rafael
authors.initials: R
authors.lastname: Borja
mesh_terms: D057919:Biological Oxygen Demand Analysis; D006885:Hydroxybutyrates / Q000737:chemistry*; D008055:Lipids / Q000032:analysis; D010100:Oxygen / Q000032:analysis*; D011091:Polyesters / Q000737:chemistry*; D011134:Polysaccharides / Q000032:analysis; D011506:Proteins / Q000032:analysis; D012722:Sewage / Q000737:chemistry*; D013696:Temperature; D013997:Time Factors; D014865:Waste Disposal, Fluid / Q000379:methods*; D000094122:Polyhydroxybutyrates
chemical_list: D006885:Hydroxybutyrates; D008055:Lipids; D010100:Oxygen; D011091:Polyesters; D011134:Polysaccharides; D011506:Proteins; D012722:Sewage; C003182:poly-beta-hydroxybutyrate; D000094122:Polyhydroxybutyrates