Title: The effect of reactor H/D ratios on the cultivation of aerobic granular sludge
Authors: Fengli Zhao; Shenjie Zhou
Addresses: School of Mechanical Engineering, Shandong University, Jinan City, Shandong 250061, China ' School of Mechanical Engineering, Shandong University, Jinan City, Shandong 250061, China
Abstract: Height to diameter ratios (H/D ratios) of the sequencing batch reactors (SBRs) are of great significance in the cultivation of the aerobic granular sludge (AGS). In this study, the gas-liquid two-phase flow patterns in the reactors with two different H/D ratios of 5 and 3 were simulated based on computational fluid dynamics (CFD). The results showed that higher H/D ratios of the reactors provided smaller liquid velocity and shear rate, but more small vortices and longer circulations compare with the lower H/D ratio reactor. Moreover, the cultivation of AGS in the two H/D ratio reactors was further investigated. It was found that reactors with higher H/D ratios can accelerate sludge granulation and retain more sludge than reactors with lower H/D ratios. However, the two reactors achieved the similar pollutant removal efficiency during the stable period, demonstrating that a high H/D ratio can enhance granulation but is not necessary for practical applications, which can reduce construction difficulties.
Keywords: aerobic granular sludge; AGS; H/D ratios; computational fluid dynamics; CFD; flow patterns; granular performance.
DOI: 10.1504/IJHST.2024.140310
International Journal of Hydrology Science and Technology, 2024 Vol.18 No.2, pp.155 - 169
Received: 17 Oct 2022
Accepted: 16 Mar 2023
Published online: 02 Aug 2024 *