title: Efficient nitrogen removal via simultaneous nitrification and denitrification in a penicillin wastewater biological treatment plant.
abstract: Nitrogen-removal performance was investigated in a penicillin wastewater biological treatment plant (P-WWTP) reconstructed from a cyclic activated sludge system (CASS) tank designed for simultaneous nitrification and denitrification (SND). Good performance was obtained during a 900-day operation period, as indicated by effluent chemical oxygen demand (COD), total nitrogen (TN) and ammonia nitrogen (NH₃‒N) values of 318 ± 34, 28.7 ± 2.4 and<0.2 mg L⁻¹ when the influent COD, total Kjeldahl nitrogen (TKN) and NH₃‒N were 3089 ± 453, 251.4 ± 26.5 and 124.8 ± 26.8 mg L⁻¹, respectively. Nitrification and denitrification occurred at different spaces, that is, 71.4% of TN removal occurred in the first 40% of the aeration tank, while 68.8% of the TKN removal occurred in 40-100% of the aeration tank. Sufficient easily biodegradable organics (EBO) in wastewater were key to the occurrence of SND. The denitrification rate under aeration conditions was 10.7 mg N g VSS⁻¹ h⁻¹ when EBO were sufficient, but 0.98 mg N g VSS⁻¹ h⁻¹ when EBO were completely degraded. Nitrification primarily occurred in the rear of the aeration tank owing to the competition for oxygen between carbonaceous oxidation and nitrification. The nitrification rate was only 7.13 mg NOD g VSS⁻¹ h⁻¹ at the beginning of the reaction, but 14.7 mg NOD g VSS⁻¹ h⁻¹ when EBO were completely degraded. These results will facilitate the improvement of nitrogen removal by existing WWTPs.
authors.affiliation: a State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control of Chemical Processes , East China University of Science and Technology , Shanghai 200237 , People's Republic of China.
authors.forename: Weiwei
authors.initials: W
authors.lastname: Luo
authors.forename: Xibiao
authors.initials: X
authors.lastname: Jin
authors.forename: Yonglian
authors.initials: Y
authors.lastname: Yu
authors.forename: Sichen
authors.initials: S
authors.lastname: Zhou
authors.forename: Shuguang
authors.initials: S
authors.lastname: Lu
mesh_terms: D000641:Ammonia / Q000378:metabolism; D057919:Biological Oxygen Demand Analysis; D019149:Bioreactors; D058440:Denitrification; D058465:Nitrification; D009584:Nitrogen / Q000378:metabolism*; D010406:Penicillins; D014865:Waste Disposal, Fluid / Q000379:methods*; D062065:Wastewater; D014874:Water Pollutants, Chemical / Q000378:metabolism*
chemical_list: D000641:Ammonia; D009584:Nitrogen; D010406:Penicillins; D062065:Wastewater; D014874:Water Pollutants, Chemical
keywords: ammonia; mechanism; penicillin wastewater; simultaneous nitrification and denitrification; total nitrogen