The pH of the reactor during the study remained
between 7.0 and 8.0 for most of the research period.
Extremes of pH are fatal for most bacteria. The
bacteria grow best when the pH is slightly on the
acidic side. The optimum range for bacterial growth
generally lies between 6.5 and 7.513
. Activated sludge
and aerated lagoons could be successfully operated
when the pH was between 9 and 10.5