FIG. 1.

EBPR performance (a) and particle size (b) of the Synthetic-1 SBR treating synthetic wastewater over a 168-day period. The vertical lines indicate where cycle changes were made to remove floccular material from the system and where the influent phosphorus concentration was halved due to an increase in the reactor volume exchange ratio; however, the total phosphorus treated did not change (see Materials and Methods). The “initial granulation” arrows indicate when the 50th-percentile particle size was above 200 μm, indicative of initial granule formation. The “mature granulation” arrows indicate when large, developed granules were present. The “fully granulated” arrows indicate when the majority of flocs were removed from the system. The 10th percentile indicates that 10% of particles were below this size distribution, the 50th percentile is the average (or median) particle size distribution, and the 90th percentile indicates 10% of the particles were above this size distribution.