pH, Tem and dissolved oxygen ...

pH, Tem and dissolved oxygen are three vital parameters in aeration tanks – DO need be maintained at 1-3 mg/L for an effective treatment as the low DO level would harm microbial mass which is difficult to reestablish.  While operation of aeration pumps is costly, allowing more than 3 mg/L looks a wasteful use of resource.  Similarly >450 C would check nitrification process and therefore the ideal is between 28 & 320C.  Similar impact at low temperatures than 28.  pH ideal is 6.5 -8.5 to avoid stress on microbial community and entertain optimal biological activity.