title: Automatic control strategy for step feed anoxic/aerobic biological nitrogen removal process.
abstract: Control of sludge age and mixed liquid suspended solids concentration in the activated sludge process is critical for ensuring effective wastewater treatment. A nonlinear dynamic model for a step-feed activated sludge process was developed in this study. The system is based on the control of the sludge age and mixed liquor suspended solids in the aerator of last stage by adjusting the sludge recycle and wastage flow rates respectively. The simulation results showed that the sludge age remained nearly constant at a value of 16 d in the variation of the influent characteristics. The mixed liquor suspended solids in the aerator of last stage were also maintained to a desired value of 2500 g/m3 by adjusting wastage flow rates.
authors.affiliation: School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China. zhuguibing@sina.com.cn
authors.forename: Gui-Bing
authors.initials: GB
authors.lastname: Zhu
authors.forename: Yong-Zhen
authors.initials: YZ
authors.lastname: Peng
authors.forename: Shu-Yun
authors.initials: SY
authors.lastname: Wu
authors.forename: Shu-Ying
authors.initials: SY
authors.lastname: Wang
mesh_terms: D019149:Bioreactors; D008962:Models, Theoretical; D009584:Nitrogen / Q000378:metabolism*; D012722:Sewage / Q000032:analysis* / Q000382:microbiology; D014865:Waste Disposal, Fluid / Q000295:instrumentation / Q000379:methods*; D018508:Water Purification / Q000295:instrumentation / Q000379:methods*
chemical_list: D012722:Sewage; D009584:Nitrogen