title: An evaluation of the performance and optimization of a new wastewater treatment technology: the air suction flow-biofilm reactor.
abstract: In this laboratory study, a novel wastewater treatment technology, the air suction flow-biofilm reactor (ASF-BR) - a sequencing batch biofilm reactor technology with a passive aeration mechanism - was investigated for its efficiency in removing organic carbon, nitrogen and phosphorus, from high-strength synthetic wastewaters. A laboratory-scale ASF-BR comprising 2 reactors, 350 mm in diameter and 450 mm in height, was investigated over 2 studies (Studies 1 and 2) for a total of 430 days. Study 1 lasted a total of 166 days and involved a 9-step sequence alternating between aeration, anoxic treatment and settlement. The cycle time was 12.1 h and the reactors were operated at a substrate loading rate of 3.60 g filtered chemical oxygen demand (CODf)/m2 media/d, 0.28 g filtered total nitrogen (TNf)/m2 media/d, 0.24 g ammonium-nitrogen (NH4-N)/m2 media/d and 0.07 g ortho-phosphate (PO4-P)/m2 media/d. The average removal rates achieved during Study 1 were 98% CODf, 88% TNf, 97% NH4-N and 35% PO4-P. During Study 2 (264 days), the unit was operated at a loading rate of 2.49 g CODf/m2 media/d, 0.24 g TNf/m2 media/d, 0.20 g NH4-N/m2 media/d and 0.06 PO4-P/m2 media/d. The energy requirement during this study was reduced by modifying the treatment cycle in include fewer pumping cycles. Removal rates in Study 2 averaged 97% CODf, 86% TNf, 99% NH4-N and 76% PO4-P. The excess sludge production of the system was evaluated and detailed analyses of the treatment cycles were carried out. Biomass yields were estimated at 0.09 g SS/g CODf, removed and 0.21 g SS/g CODf, removed for Studies 1 and 2, respectively. Gene analysis showed that the use of a partial vacuum did not affect the growth of ammonia-oxidizing bacteria. The results indicate that the ASF-BR and passive aeration technologies can offer efficient alternatives to existing technologies.
authors.affiliation: a Civil Engineering, College of Engineering and Informatics , National University of Ireland, Galway , Galway , Ireland.
authors.forename: P
authors.initials: P
authors.lastname: Forde
authors.forename: C
authors.initials: C
authors.lastname: Kennelly
authors.forename: S
authors.initials: S
authors.lastname: Gerrity
authors.forename: G
authors.initials: G
authors.lastname: Collins
authors.forename: Eoghan
authors.initials: E
authors.lastname: Clifford
mesh_terms: D000641:Ammonia / Q000378:metabolism; D018441:Biofilms; D019149:Bioreactors; D009584:Nitrogen / Q000302:isolation & purification; D009930:Organic Chemicals / Q000302:isolation & purification; D010084:Oxidation-Reduction; D010100:Oxygen / Q000032:analysis; D010758:Phosphorus / Q000302:isolation & purification; D012722:Sewage / Q000737:chemistry; D014618:Vacuum; D018508:Water Purification / Q000295:instrumentation*
chemical_list: D009930:Organic Chemicals; D012722:Sewage; D010758:Phosphorus; D000641:Ammonia; D009584:Nitrogen; D010100:Oxygen
keywords: biofilm; biofilm analysis; high-strength synthetic wastewater; low energy; sequencing batch biofilm reactor