Anaerobic substrate uptake by the enhanced biological phosphorus removal activated sludge treating real sewage

The enhanced biological phosphorus removal (EBPR) activated sludge process is a wastewater treatment process by which not only organic pollutants but also phosphorus are removed. In the EBPR process, it is known that organic matter in the influent is removed in the anaerobic phase of the sequencing anaerobic and aerobic conditions. Although the mechanism of the anaerobic substrate uptake is being revealed, the existing observations are based on the experiments with activated sludge acclimatized with synthetic sewage, or synthetic media. In this study, the anaerobic substrate uptake by EBPR activated sludge treating real sewage was examined. The sludge was obtained from a pilot plant of the University of British Columbia, Canada. And as the substrate, acetate, propionate, lactate, pyruvate, malate, succinate, and fermented sewage were examined. The results clearly showed that most part of the sink of carbon anaerobically taken up is explained by PHA (poly 3-hydroxyalkanoates), and that glycolysis is playing a significant role in the anaerobic uptake of acetate and propionate. Copyright (C) 1996 IAWQ.