Characterization of Aerobic Granular Sludge (AGS) Formation During Start-Up Phase for Leachate Treatment

The treatment of landfill leachate at Pulau Burung, Penang was investigated by applying aerobic granular sludge (AGS) during Start-up. The AGS was grown from a lab-scale with 10 L working volume of sequencing batch reactor (SBR). An achievement of AGS reactors in treatment and effluent quality shows the soluble chemical oxygen demand (CODs) have a small difference with total chemical oxygen demand (CODt) as an effluent quality parameter. In the biological process, a beginning rate of oxygen uptake rate (OUR) was fluctuates, the granules reached maximum value on day 47 with 0.85 (mg O₂/L/min) that shows the maximum value due to microbes are quickly growing and reproducing. The sludge retention time (SRT) was conducted in a range of 3–25 d, fluctuate between days 0 and 50 that indicates the SBR system was unstable and immature aerobic granules until day 50. The AGS morphology shows although the granules not matured yet during Start-up but the settling properties exhibited at 47 days indicating good settleability when obtained the sludge volume index (SVI₃₀) between 50 and 80 mL/g. The efficiencies of ammonium removal is above 95% from days 30 to 50 with pH value of 7.9–8.2 but adversely when pH value more than 8.5.