title: Nutrients removal in hybrid fluidised bed bioreactors operated with aeration cycles.
abstract: Abstract Two hybrid fluidised bed reactors filled with sepiolite and granular activated carbon (GAC) were operated with short cycled aeration for removing organic matter, total nitrogen and phosphorous, respectively. Both reactors were continuously operated with synthetic and/or industrial wastewater containing 350-500 mg COD/L, 110-130 mg NKT/L, 90-100 mg NH3-N/L and 12-15 mg P/L for 8 months. The reactor filled with sepiolite, treating only synthetic wastewater, removed COD, ammonia, total nitrogen and phosphorous up to 88, 91, 55 and 80% with a hydraulic retention time (HRT) of 10 h, respectively. These efficiencies correspond to removal rates of 0.95 kgCODm(-3)d(-1) and 0.16 kg total N m(-3)d(-1). The reactor filled with GAC was operated for 4 months with synthetic wastewater and 4 months with industrial wastewater, removing 98% of COD, 96% of ammonia, and 66% of total nitrogen, with an HRT of 13.6 h. No significant phosphorous removing activity was observed in this reactor. Microbial communities growing with both reactors were followed using polymerase chain reaction (PCR) and denaturing gradient gel electrophoresis (DGGE) techniques. The microbial fingerprints, i.e. DGGE profiles, indicated that biological communities in both reactors were stable along the operational period even when the operating conditions were changed.
authors.affiliation: Department of Chemical Engineering and Environmental Technology, University of Valladolid, C/ Dr. Mergelina s/n, 47005 Valladolid, Spain
authors.forename: Martin
authors.initials: M
authors.lastname: Martin
authors.forename: L López
authors.initials: LL
authors.lastname: Enríquez
authors.forename: M
authors.initials: M
authors.lastname: Fernández-Polanco
authors.forename: S
authors.initials: S
authors.lastname: Villaverde
authors.forename: P A
authors.initials: PA
authors.lastname: Garcia-Encina
mesh_terms: D001419:Bacteria / Q000235:genetics / Q000378:metabolism; D018441:Biofilms; D018533:Biomass; D019149:Bioreactors; D002244:Carbon; D017633:Magnesium Silicates; D009584:Nitrogen / Q000302:isolation & purification* / Q000378:metabolism; D010758:Phosphorus / Q000302:isolation & purification* / Q000378:metabolism; D012329:RNA, Bacterial / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D014865:Waste Disposal, Fluid / Q000379:methods*; D014873:Water Pollutants / Q000302:isolation & purification* / Q000378:metabolism
chemical_list: D017633:Magnesium Silicates; D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S; D014873:Water Pollutants; D010758:Phosphorus; D002244:Carbon; C001671:magnesium trisilicate; D009584:Nitrogen