Modeling sequencing batch reactor operational conditions depending on oxygen concentration

Abstract

Sequencing batch reactors (SBR) can be used as a fill-and draw activated sludge system for wastewater treatment with considerable operating flexibility and the possibility to conduct experiments under standard conditions and extreme case scenarios. Mathematical modeling and computer simulations provide an opportunity to implement existing wastewater processes in modeling software and evaluate different modifications at low costs and no disturbances for on-going processes of full scale WWTP. Additionally, the used model can be calibrated and validated against experimental data from laboratory scale devices. The aim of this study was to simulate the processes occurring in laboratory scale SBR under different aeration strategies. The results include the analysis of the adaptation period of the activated sludge biomass in the SBR, as well as the case of breakdown of treatment process due to stoppage of raw wastewater inflow and the interruption of the aeration and/or mixing. As a result, it can be stated that the oxygen transfer rate should be incorporated in the calibration of biological nutrient removal model in order to effectively visualize the individual contributions of each process.

Evaluation of the efficiency of the mixing system of the laboratory SBR-type reactor

“…For the catchments with particularly sensitive waters, wastewater must undergo additional treatment [9][10][11]. Wastewater of domestic and municipal origin is most often treated by using biological methods [4,[12][13][14][15]. Biological treatment involves the use of a process agent, which is properly shaped and prepared biological material [4,[16][17][18][19][20].…”

“…After the entire wastewater treatment cycle is completed, both the agitator and the aeration system are turned off and the sedimentation process of the sludge begins in the same tank. During this process, the sludge composed of microorganisms settles slowly to the bottom, thickening, which results in an enlarged layer of treated wastewater in the upper part [3,9,15].…”

“…Technological trends strive to increase the reliability of equipment for the wastewater treatment process, which determines the use of innovative working methods in the design and construction of new technical solutions [15,36,37]. The purpose of this study was to analyze an innovative mixing system produced by additive deposition technology and to evaluate the energy efficiency of the process in laboratory-scale SBR-type bioreactors.…”