Effect of reactor height/diameter ratio and organic loading rate on formation of aerobic granular sludge in sewage treatment

Although a high volume of research on aerobic granular sludge exists in the body of related literature, the determination of biokinetic parameters of aerobic granules using a linear plot for biodegradation of real wastewater has rarely been discussed. Therefore, this study aims to determine the biokinetic parameters of aerobic granules that develop in a sequencing batch reactor (SBR) with sewage as a substrate, using a linear plot. The difference in biokinetic parameter (k, K-s, Y, K-d and mu(max)) values gathered from five aerobic granules batches were tested as whether it is linearly correlated with the variable organic loading rate (OLR) and reactor height/diameter (H/D) ratio. The R-2 value of 0.97 and 0.82 was obtained from the linear correlation between mu(max) and reactor HID ratio, and Y and OLR, respectively. This demonstrates that biomass production (Y and mu(max)) proportionally depends on the increase in OLR and reactor H/D ratio. This might be because the effectiveness of the aerobic granules measured by K-s are greater in high H/D ratio reactors with values over 315 mg/L as compared to less than 276 mg/L in low H/D ratio reactors. (C) 2016 Elsevier Ltd. All rights reserved.