Verification of Enhanced Phosphate Removal Capability in Pure Cultures of Acinetobacter calcoaceticus under Anaerobic/Aerobic Conditions in an SBR

Laboratory experiments were conducted using pure cultures of Acinetobacter under an-aerobic/aerobic cyclic conditions to explain the release and uptake of soluble phosphate in an activated sludge process showing enhanced biological phosphate removal (EBPR). Under anaerobic/aerobic cyclic conditions in a Sequencing Batch Reactor (SBR), COD uptake concurrent with soluble phosphate release by Acinetobacter was not significant during the anaerobic periods, indicating that EBPR would not be established in pure cultures. However Acinetobacter cells accumulated higher phosphate content (5.2%) in SBR than that obtained (4.3%) from batch experiments. These results suggest that Acinetobacter sp. may not follow the proposed pattern of behavior of poly-P bacteria in EBPR activated sludge Plants.