Foaming can be chemical ...
Published by Michael Dooley
Foaming can be chemical surfactant causing or possible combination of low sludge age, high DO and low loading (BOD). If you have high DO your can add anti-foam untill the sludge age improves. Increase pH in SBR is possibly Denitrification of high Nitrate levels in influent which generates alkalinity. What is total N in influent.