An enhanced biological phosphorus removal (EBPR) control strategy for sequencing batch reactors (SBRs)

A control strategy was developed for enhanced biological phosphorus removal (EBPR) in a Sequencing Batch Reactor (SBR). Unlike past research that focu sed on maximizing polyhdroxyalkanoate (PHA) formation during the anaerobic period, this study investigated some of the factors that govern aerobic PHA dynamics and its efficient regulation during phosphate (P) uptake. Influen t COD, influent P, and the time for aeration were critical factors that gov erned PHA use and P uptake during aerated react. Unnecessary PHA oxidation (i.e., in the absence of extracellular P) occurred ii the time for aerated react exceeded the time required for P uptake. By adjusting the aeration ti me to that required for P uptake, residual PHA was sustained in the SBR and excess phosphate uptake reaction potential (PRP) was generated for use dur ing transient influent excursions in P. Unlike space oriented systems, the time for react is simply adjusted in the SBR. Because residual PHA is easil y maintained once achieved, high influent COD events can be harnessed to in crease or sustain excess PRP for management of expected variations in influ ent P.