title: Nitrogen removal in a SBR operated with and without pre-denitrification: effect of the carbon:nitrogen ratio and the cycle time.
abstract: The effects of cycle time (CT) (8, 12 and 16h) and C/N ratio (3, 6 and 9) on nitrogen removal efficiencies in a bench top sequencing batch reactor treating slaughterhouse wastewater were investigated under different operating conditions: in condition 1, the reaction comprises an aerobic/anoxic phase and in condition II, the reaction comprises anoxic I/aerobic/anoxic II phases (with pre-denitrification). The greatest percentages of nitrogen removal were obtained in the CT range from 12 to 16 h and C/N ratios from 3 to 6, with mean efficiency values of 80.76% and 85.57% in condition I and 90.99% and 91.09% in condition II. Although condition II gave a higher removal of total inorganic nitrogen (NH4+ - N + NO2- - N + NO3- - N) than condition I, only condition I showed statistically significant and predictive regression for all the steps of nitrogen removal.
authors.affiliation: Center for Biological and Environmental Sciences, Federal Technological University of Parancá - UTFPR, Avenida Brasil 4232, Medianeira 85884000, Brazil. juliana@utfpr.edu.br
authors.forename: Juliana Bortoli Rodrigues
authors.initials: JB
authors.lastname: Mees
authors.affiliation: PGEAGRI/CCET- Center of Exact Sciences and Technology, State University of Western of Parana-UNIOESTE, Rua Universitária 2069, Cascavel 85819110, Brazil.
authors.forename: Simone Damasceno
authors.initials: SD
authors.lastname: Gomes
authors.affiliation: PGEAGRI/CCET- Center of Exact Sciences and Technology, State University of Western of Parana-UNIOESTE, Rua Universitária 2069, Cascavel 85819110, Brazil.
authors.forename: Salah Din Mahmud
authors.initials: SD
authors.lastname: Hasan
authors.affiliation: PGEAGRI/CCET- Center of Exact Sciences and Technology, State University of Western of Parana-UNIOESTE, Rua Universitária 2069, Cascavel 85819110, Brazil.
authors.forename: Benedito Martins
authors.initials: BM
authors.lastname: Gomes
authors.affiliation: PGEAGRI/CCET- Center of Exact Sciences and Technology, State University of Western of Parana-UNIOESTE, Rua Universitária 2069, Cascavel 85819110, Brazil.
authors.forename: Márcio Antonio Vilas
authors.initials: MA
authors.lastname: Boas
mesh_terms: D000003:Abattoirs / Q000295:instrumentation; D001419:Bacteria / Q000378:metabolism*; D061249:Batch Cell Culture Techniques / Q000295:instrumentation; D019149:Bioreactors / Q000382:microbiology*; D002244:Carbon / Q000378:metabolism*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D058465:Nitrification / Q000502:physiology; D009584:Nitrogen / Q000302:isolation & purification / Q000378:metabolism*; D013997:Time Factors; D062065:Wastewater / Q000382:microbiology*; D014874:Water Pollutants, Chemical / Q000302:isolation & purification / Q000378:metabolism*; D018508:Water Purification / Q000295:instrumentation*
chemical_list: D002244:Carbon; D009584:Nitrogen; D062065:Wastewater; D014874:Water Pollutants, Chemical