Different alternative configurations and strategies for the simultaneous biological removal of organic matter and nutrients (N and P) in wastewater have been proposed in the literature. This work demonstrates a new successful strategy to bring in enhanced biological phosphorus removal (EBPR) to a conventional nitrification/denitrification system by means of bioaugmentation with an enriched culture of phosphorus accumulating organisms (PAO). This strategy was tested in a sequencing batch reactor (SBR), where an 8. h configuration with 3. h anoxic, 4.5. h aerobic and 25. min of settling confirmed that nitrification, denitrification and PAO activity could be maintained for a minimum of 60. days of operation after the bioaugmentation step. The successful bioaugmentation strategy opens new possibilities for retrofitting full-scale WWTP originally designed for only nitrification/denitrification. These systems could remove P simultaneously to COD and N if they were bioaugmented with waste purge of an anaerobic/aerobic SBR operated in parallel treating part of the influent wastewater. © 2011 Elsevier Ltd.
- Activated sludge
- Enhanced biological phosphorus removal (EBPR)
- Nitrogen removal
- Polyphosphate accumulating organisms (PAO)