Our SBR design in Rosebery ...

Our SBR design in Rosebery Tasmania has achieved < 0.5mg/l TP consistently over 3 years, Ammonia7pH on discharge as N removal takes up alkalinity and the influent Municipal stream has inherent low alkalinity. Flow varies 400kL to 3ML/d in cold environment.  Inflow 8 to 15C.  Cold climates have low temp nitrifiers in the waste stream almost invariably. We also add a small amount of liquid sugar to ensure full TN removal. We do not use any chemical P strip. It is full uptake by PAO.  We have 20 years and nearly 40 full scale plants. Plants like all activated sludge plants foam with fluffy white foam while biomass is being conditioned. It is a reaction of the organisms to different food sources. Once you  breed a biomas that has something that likes all food sources ever found in the waste water foaming should stop. Foaming is easy to manage. The easiest step is to discontinue aeration for a short period (minutes) until foaming settles.  If 'shiny foam then too much biomass or not enough O2 or both.  Selection of non foaming biomass takes at most a few days. At worst an intervention with silicone antifoam can be used to get over the hump. Gerardi is OK but way off the mark on some things. It is just an activated sludge system with 100% biomass available in the react chamber.  You can reproduce almost any theoretical condition you want from the literature. The secret is measure the process so you can control the process. Oh and then control it!