These results might be related to the highest temperature in SBR50 compare to the temperature in SBR30 and SBR40. Chang and Lin (2006) reported high temperature led to high ash content in biogranules and consequently increase their size. The granules in all the bioreactors kept growing reaching the final stage of the experiment in a much lower speed with better sludge properties. Both MLSS and MLVSS reached steady state at 10.6 g L-1 and 6.5 g L-1, respectively for SBR30. While the biomass concentrations in SBR40 represents 7.8 g L-1 for MLSS and 5.4 g L-1 for MLVSS. Additionally for SBR50, both MLSS and MLVSS concentrations became stable at about 7 g L-1 and 5.5 g L-1, respectively. The settling properties in terms of SVI for granules at 30 °C, 40 °C and 50 °C reached 63.21 mL g-1, 47.4 mL g-1 and 24.5 mL g-1, respectively which is in agreement with the result reported by Ebrahimi et al. (2010) indicating good settling ability achieved at the end of the experiment