Proceedings

Sequencing Batch Reactors (SBRs) have not been successful in biological phosphorus removal (BioP) compared to e.g. modified UCT ASPs. In an attempt to improve conditions for Bio-P, an advanced process controller was implemented in a continuous flow SBR in a 20 m3/day R&D pilot plant and a 800 m3/day full scale plant. The controller optimised the treatment conditions during the whole cycle through online measurements of the process. It was found to optimize aeration schemes to provide anoxic and anaerobic treatment both during the reaction phase and settling phase, which together with the continuous carbon source improved denitrification and Bio-P. By using both the react and settling phase for anaerobic phosphorus release an influent average total phosphorus of 7.4 mg/l was reliably reduced to an effluent below 1 mg/l without chemical addition for P removal. The improved aeration efficiency and reduced chemical use gave significant OPEX savings and up to 20% less energy consumed.