title: Boosting nitrification by membrane-attached biofilm.
abstract: Nitrification is a key step for reliable biological nitrogen removal. In order to enhance nitrification in the activated sludge (AS) process, membrane-attached biofilm (MAB) was incorporated in a conventional activated sludge tank. Simultaneous organic carbon removal and nitrification of the MAB incorporated activated sludge (AS + MAB) process was investigated with continuous wastewater treatment. The effluent TOC concentration of AS and the AS + MAB processes were about 6.3 mg/L and 7.9 mg/L, respectively. The TOC removal efficiency of both AS and AS + MAB were above 95% during the wastewater treatment, indicating excellent organic carbon removal performance in both processes. Little nitrification occurred in the AS process. On the contrary, successful nitrification was obtained with the AS + MAB process with nitrification efficiency of about 90%. The volumetric and surface nitrification rates were about 0.14 g/Ld and 6.5 g/m2d, respectively. The results clearly demonstrated that nitrification in the conventional AS process was boosted by MAB. Furthermore, the microfaunal population in the AS + MAB process was different from that in the AS process. The high concentration of rotifers in the AS + MAB process was expected to decrease the generation of excess sludge in the process.
authors.affiliation: Department of Chemistry and Chemical Engineering, Niigata University 8050, Ikarashi 2, Niigata City 950-2181, Japan.
authors.forename: C Y
authors.initials: CY
authors.lastname: Wu
authors.forename: S
authors.initials: S
authors.lastname: Ushiwaka
authors.forename: H
authors.initials: H
authors.lastname: Horii
authors.forename: K
authors.initials: K
authors.lastname: Yamagiwa
mesh_terms: D001419:Bacteria / Q000254:growth & development; D018441:Biofilms; D002244:Carbon / Q000302:isolation & purification / Q000378:metabolism; D008566:Membranes; D009573:Nitrites / Q000737:chemistry / Q000378:metabolism*; D009584:Nitrogen / Q000302:isolation & purification / Q000378:metabolism; D009930:Organic Chemicals / Q000737:chemistry / Q000378:metabolism; D012722:Sewage / Q000032:analysis / Q000737:chemistry*; D012828:Silicones / Q000737:chemistry; D013997:Time Factors; D014865:Waste Disposal, Fluid / Q000295:instrumentation / Q000379:methods*
chemical_list: D009573:Nitrites; D009930:Organic Chemicals; D012722:Sewage; D012828:Silicones; D002244:Carbon; D009584:Nitrogen