Activated sludge is a biological treatment that commonly deals with the problem of excess sludge production. As advanced technology, aerobic granular sludge is expected to address the drawbacks of the activated sludge system, including the excess sludge issue. This study aims to investigate the characteristics and performance of the activation process of excess sludge. The study was conducted in a sequencing batch reactor with different substrate compositions in three phases. The activation process with biodegradable substrate supported by nutrients and micronutrients consisting of cations successfully enhanced the growth of microorganisms to 6720 mg/L of MLSS and 5450 mg/L of MLVSS. The settling performance of the sludge increased, marked by a low average of SVI5 of 63.89 mL/gTSS and SVI30 of 45.16 mL/gTSS. The treatment improved COD removal to 90 % and ammonia, nitrate, and phosphate removal to 98 %, 47 %, and 37 %, respectively. The granulation process with micronutrients as cation addition in 25 mg/L has not been achieved through the experiment in 18 days indicated by the ratio of SVI30 to SVI5 on the average of 0.71. Therefore, the findings suggest that the study of substrate and cation concentration to accelerate the granulation is proposed towards AGS technology and its application to achieve a sustainable environment.