Mass balance for an in situ estimation of the activated sludge specific oxygen uptake rate
In activated sludge wastewater treatment plants, the activity of the biomass is essential if effluent quality standards are to be met. One of the parameters that characterizes the activity of activated sludge is the specific oxygen uptake rate (the amount of oxygen consumed per unit mass of biomass and per unit time). This rate may be measured using specialised apparatus (respirometer) or deduced from on-line measurements. A technique to deduce the specific oxygen uptake rate from simple measurements (flow rate, dissolved oxygen concentrations) has been developed and tested. This technique involves low cost probes and therefore specific oxygen uptake rate estimations may be used for treatment plant automation.