Removing Zoogloea From Wastewater
Problem statement:

A 1 million gallon per day biological wastewater treatment system received influent wastewater containing high concentrations of organic acids (especially acetic acid), other materials with high total organic carbon, spent aluminum sulfate, and exhibits a pH typically in the range of 3.5.

The wastewater aeration basin is known to exhibit low dissolved oxygen (0.5 mg/l) but more notably has given rise to a tremendous growth of zooglia organisims which has significantly inhibited the settling of the wastewater sludge and in turn has caused very high effluent BOD and toxicity.

Notwithstanding the need for greater oxygenation of the system's aerated lagoon, is there a chemical or other physio-chemical means of eliminating the troublesome zooglia organisms and returning the wastewater system to good health?

Intuitievely, it would seem like an increase in pH, possibly via the addition of potassium/sodium/calcium carbonate would improve not only pH but add much needed buffer to the system. However, what could we do to rid this system of the troublesome zooglia bacteria and improve the settlability of other solids?