If you have access to the ...

If you have access to the book "Troubleshooting the Sequencing Batch Reactor" by Michael Gerardi, there are suggestions as to solutions once the ratio of filamentous organisms to beneficial floc are calculated by lab analysis the conditions can be deciphered to develope an appropriate solution: Sources include: excess FOG materials, high MCRT, low dissolved oxygen levels, low F/M ratios, nutrient deficiency, readily-degradable substances such as short chain acids and alcohols, and septicity and sulfides, pH outside the optimal range +/- >1 .  Foam is from the secretion of hydrophobic compounds or the productions of lipids and biosurfactants that capture air and gas bubbles creating the light brown foam. Returning the floc to an appropriate density and cell ratio is the objective.