title: Promotion of nitrifiers through side-stream bioaugmentation: a full-scale study.
abstract: Bioaugmentation of nitrifiers from a side-stream treatment is an efficient method for boosting the mainstream process at a wastewater treatment plant (WWTP). Although this technology has been known for several years, the number of full-scale applications for it is limited. For a WWTP approaching its critical nitrogen load capacity, the benefits are doubled if the introduced side-stream treatment for digester supernatant is combined with bioaugmentation. Not only is the nitrogen load to the mainstream process decreased by 10-25%, but the mainstream process is also boosted with nitrifiers, increasing the nitrifying capacity. In this full-scale study, the increment of the nitrification rate is examined in the mainstream process at different temperatures and at different flow rates of returned activated sludge to the side-stream treatment. Our results show that the nitrification rate in the mainstream process was increased by 41% during the coldest period of the study, implying that the examined WWTP could treat considerably higher nitrogen loads if bioaugmentation were permanently installed.
authors.affiliation: VA-Ingenjörerna AB, Trädgårdsgatan 12, SE-702 12 Örebro, Sweden E-mail: fredrik.stenstrom@vaing.se; Water and Environmental Engineering, Department of Chemical Engineering, Lund University, Lund SE-221 00, Sweden.
authors.forename: F
authors.initials: F
authors.lastname: Stenström
authors.affiliation: Water and Environmental Engineering, Department of Chemical Engineering, Lund University, Lund SE-221 00, Sweden.
authors.forename: J
authors.initials: J
authors.lastname: la Cour Jansen
mesh_terms: D001419:Bacteria / Q000378:metabolism*; D019149:Bioreactors / Q000382:microbiology*; D058465:Nitrification; D009584:Nitrogen / Q000737:chemistry / Q000378:metabolism*; D012722:Sewage / Q000737:chemistry / Q000382:microbiology*; D014865:Waste Disposal, Fluid; D062065:Wastewater / Q000737:chemistry*; D014871:Water Microbiology; D014874:Water Pollutants, Chemical
chemical_list: D009584:Nitrogen; D012722:Sewage; D062065:Wastewater; D014874:Water Pollutants, Chemical