The purpose of this study was to propose a method to determine the aeration time needed in the SBR for oxidation of easily biodegradable organic matter. The method proposed consists of applying the concept of equations of non-linear differences to the data of oxygen utilization rate (OUR) The experimental data used in the study were obtained from a bench scale SBR. The mean times required for oxidation of easily degradable organic matter were 0.83, 0.83, 1.17 and 1.54 hours for sludges aged 30, 20, 10 and 5 days, respectively. These values were similar to the values recommended in the literature on activated sludges. The method proposed here is easy to apply to the OUR data and provides a contribution in seeking to minimize the operating costs of the SBR.
Sequencing batch reactor; SBR; oxygen uptake rate; react period; wastewater