Kinetic modelling of biological phosphorus removal with a pure culture of Acinetobacter sp under aerobic, anaerobic and transient operating conditions

Laboratory-scale batch experiments were conducted for a purr culture of Aci netobacter sp. aiming to develop a kinetic model for the aerobic growth of the bacterium under phosphate and carbon-limited conditions. The ability of the bacterium to take up more phosphorus than is normally needed for cell growth and store it intracellularly as polyphosphate was verified. A suffic iently accurate kinetic model, describing the behaviour of the bacterium un der polyphosphate- and carbon-limited anaerobic conditions, was then develo ped. The transient characteristics of batch cultivation systems with Acinet obacter sp, cells to changes from anaerobic to aerobic conditions and vice- versa wore studied in the sequel and an appropriate integrated kinetic mode l was developed. The model describes adequately the dynamic behaviour of th e poly-P bacterium under strictly anaerobic, strictly aerobic and transient conditions. Model predictions were validated with batch experiments conduc ted under transient aerobic/anaerobic conditions. Acinetobacter sp. cells p resented a rapid adaptation ability to either aerobic or anaerobic conditio ns during shifting from one environment to the other. Batch experimentally observed profiles of biomass growth. acetate consumption and phosphorus upt ake and release were found to be in excellent agreement with the predicted ones by the overall kinetic model. (C) 1999 Elsevier Science Ltd. All right s reserved.