title: Biological nitrogen removal using a vertically moving biofilm system.
abstract: In this study, a biological nitrogen removal process using a vertically moving biofilm system was used to treat synthetic wastewater. The process consisted of two pre-denitrification units, one combined carbonaceous removal/nitrification unit and three nitrification units. Each unit employed biofilm growth on a plastic module. In the anoxic units, the modules were vertically moved, while always submerged, in the bulk fluid; in the aerobic units, they were moved vertically up into the air and down into the wastewater. Three small-scale experiments, having different recirculation ratios and influent loadings, were conducted at a controlled temperature of 11 degrees C. In this system, the carbonaceous removal efficiency was in the range of 94-96% and the total nitrogen removal efficiency was 77-82%. In the anoxic units, the denitrification efficiency was 94-98% and the areal denitrification rates, based on the surface area of the biofilm modules, were 2.9-3.8 g NO3-N/(m2 x d). The nitrification efficiency occurring in the aerobic tanks was up to 95% and the maximum areal ammonium removal rates were 1.3-1.8 g NH4-N/(m2 x d).
authors.affiliation: Department of Civil Engineering, National University of Ireland, Galway, Ireland.
authors.forename: Michael
authors.initials: M
authors.lastname: Rodgers
authors.forename: Xin-Min
authors.initials: XM
authors.lastname: Zhan
mesh_terms: D001419:Bacteria / Q000378:metabolism*; D018441:Biofilms; D019149:Bioreactors; D009584:Nitrogen / Q000378:metabolism*; D010100:Oxygen / Q000378:metabolism; D000644:Quaternary Ammonium Compounds / Q000378:metabolism; D013696:Temperature; D013997:Time Factors; D014865:Waste Disposal, Fluid / Q000379:methods*
chemical_list: D000644:Quaternary Ammonium Compounds; D009584:Nitrogen; D010100:Oxygen