Physical characteristics and removal performance of aerobic granular sludge in biological treatment of domestic wastewater

Abstract

This study aims to demonstrate the formation of aerobic granular sludge (AGS) for domestic wastewater treatment applications in hot climate and low humidity conditions (e.g. Saudi Arabia) as well as to characterize and examine the bioreactor performance in removing organic matter and nutrients. Based on the study, aerobic granular sludge (seeded with domestic activated sludge from Al-Madina Wastewater Treatment Plant and fed with synthetic wastewater with an organic loading rate (OLR) of 1.6 kg COD m-3d-1) was successfully cultivated with average size ranging from 1 to 2 mm in a laboratory scale sequencing batch reactor (SBR) system operated at 30 days with a complete cycle time of 3 h and at the working temperature of 30 ± 1°C. Results also showed that the aerobic granular sludge formed had excellent settling ability (settling velocity, 38.98 mh-1 and MLSS, 7.8 gL-1) and great removal performance of COD and nutrient (i.e. more than 90%).