Modeling for Collecting Kinetic and Microbial Population to Study Bio-P Elimination

A SBR (Sequencing Batch Reactor) was used to study the kinetics of the processes involved in the Enhanced Biological Phosphorus Removal (EBPR) from wastewater. In addition to the batchwise operated reactor, two types of continuous plants, an A2/O (Anaerobic-Anoxic-Oxic) system and a UCT (University of Cape Town) system, have been operated to cultivate phosphorus removing sludge. Growth of phosphorus accumulating organisms has been established. Concentration profiles indicate the possibility for complete phosphorus removal during the aerobic period. Kinetic models have been calibrated for anaerobic phosphate release and aerobic phosphate uptake. The models have been validated using experimental data from the different plants. The bacterial population of both the A2/O and the SBR remained stable over the period tested. However, the majority of the organisms isolated from the A2/O belonged to the Enterobacteriaceae, while the population of the SBR system was different. Representatives of Acinetobacter, regarded as a possible causal agent for biological phosphate removal, were only occasionally present in the sludge.