These days, aerobic granulated sludge (AGS) is used with success in SBR-reactors with the NEREDA© process to clean wastewater on a municipal and industrial level. The compact structure and the higher density of the granulated sludge leads to improved settling properties. Another particularity of plants with AGS is the possibility of a simultaneous nitrification denitrification (SND). Due to the development of individual zones with various oxygen and nutrient gradients, the processes are no longer determined by the circumstances in the exterior medium, but are defined by the predominant properties of the different zones. Besides nitrogen compounds phosphate accumulating organisms (PAOs) deposit within the granule, so that the possibility of a biological phosphate removal is given as well (Winkler et al., 2012). The aeration strategy has a significant influence at the growth behaviour of the various microorganisms within a granule.^ If the oxygen level in the exterior medium is too high, the oxygen can penetrate in the anaerobic zone and influence the growth of denitrifying and phosphate accumulating organisms, whereby the nutrient removal is impeded (Lochmatter et al., 2013). In this master thesis are analysed and evaluated different aeration strategies based on similar studies of AGS in SBR-reactors. The objective of this thesis is the testing of various aeration strategies in the SBR-operation and the optimization of the settings in terms of a high nutrient removal with, simultaneously, a compact and dense structure of the granules. Furthermore, the findings of the SBR-operation are used to put to test the operation in a continuous flow reactor. To analyse the influence of the aeration at the AGS, two SBR-reactors and one continuous flow reactor have been operated. One of the SBR-reactors was aerated intermittently, the other one was aerated in such a way that a constant oxygen level was set.^ The continuous flow reactor was operated in such a way that the conditions of the SBR-operation could be reproduced as closely as possible. Over a 125 days¿ period, samples were taken daily, the reactors were supervised and the main parameters continuously recorded. A daily supervision of the setup was thereby necessary. The 125 days were divided into 4 phases with different operating parameters. Results of the previous phase were thereby used for the optimization of the next phase to improve the cleaning performance as well as the settling properties of the AGS. For these tests, wastewater of the TU-Vienna was used in the first 106 days to generate a representative inflow of a municipal reactor. Good settling properties with SV5/SV30-Ratios near 1 and an SVI below 50 [ml/g] could be measured in the first 30 days. The high selection with a settling time of 2 [min] lead to dense particles in the SBR-system.^ However, this selection had a negative impact on the TS-content because a lot of biomass got lost. With the selected aeration strategy, no constant nitrification and denitrification could be ensured, whereby the removal of the nitrogen was steadily decreasing and showed high fluctuations. With the increase of the anaerobic feeding time by 30 [min] was it possible to achieve a Tot.N-removal of more than 70 [%] for the SBRs. De Kreuk et al. (2005a) and Wagner et al. (2015) have already shown that a longer charging time has a positive effect on the formation of the anoxic layer within the granules, thereby also increasing denitrification and biological phosphate removal. In the last two phases, filamentous bacteria were dominant in the SBR2 with intermittent aeration and the continuously flowing system, which significantly depreciated the sedimentation properties of the activated sludge It was not possible to maintain or promote granulation in the continuous flow system.^ The sludge volume ratios were for the most part above 1.5 and the SVI was between 80 and 140 [ml / g]. In the last two phases, the Tot.N-removal was over 70 [%]. For the operation of AGS in a continuously flowing plant, further investigations must be undertaken.