title: Anaerobic whey treatment by a stirred sequencing batch reactor (ASBR): effects of organic loading and supplemented alkalinity.
abstract: An assessment was made of cheese whey treatment in a mechanically stirred anaerobic sequencing batch reactor (ASBR) containing granular biomass. The effect of increasing organic load and decreasing influent alkalinity supplementation (as sodium bicarbonate) was analyzed. The reactor operated on 8-h cycles with influent COD concentrations of 500, 1000, 2000 and 4000 mg/L, corresponding to volumetric organic loads of 0.6 to 4.8 mgCOD/L.d. Organic COD removal efficiencies were always above 90% for filtered samples. These results were obtained with an optimized alkalinity supplementation of 50% (ratio between mass of NaHCO3 added and mass of influent mgNaHCO3/mgCOD) in the assays with 500 and 1000 mgCOD/L and of 25% in the assays with 2000 and 4000 mgCOD/L. Initial alkalinity supplementation was equal to the mass of influent COD (100%). The system showed formation of viscous polymer-like substances. These were probably of microbiological origin occurring mainly at influent CODs of 2000 and 4000 mg/L and caused some biomass flotation. This could, however be controlled to enable efficient and stable reactor operation.
authors.affiliation: Departamento de Engenharia Química e de Alimentos-Escola de Engenharia Mauá-Instituto Mauá de Tecnologia (IMT); Praça Mauá 1; CEP 09.580-900; São Caetano do Sul-SP; Brazil.
authors.forename: Gustavo
authors.initials: G
authors.lastname: Mockaitis
authors.forename: Suzana M
authors.initials: SM
authors.lastname: Ratusznei
authors.forename: José A D
authors.initials: JA
authors.lastname: Rodrigues
authors.forename: Marcelo
authors.initials: M
authors.lastname: Zaiat
authors.forename: Eugenio
authors.initials: E
authors.lastname: Foresti
mesh_terms: D000818:Animals; D001421:Bacteria, Anaerobic / Q000378:metabolism*; D018533:Biomass; D019149:Bioreactors; D002417:Cattle; D002611:Cheese; D003612:Dairying / Q000379:methods; D004305:Dose-Response Relationship, Drug; D006863:Hydrogen-Ion Concentration; D007220:Industrial Waste; D008894:Milk Proteins / Q000378:metabolism*; D010100:Oxygen / Q000032:analysis / Q000378:metabolism; D017693:Sodium Bicarbonate / Q000378:metabolism* / Q000494:pharmacology; D014865:Waste Disposal, Fluid / Q000379:methods*; D000067816:Whey Proteins
chemical_list: D007220:Industrial Waste; D008894:Milk Proteins; D000067816:Whey Proteins; D017693:Sodium Bicarbonate; D010100:Oxygen