Effects of wastewater type on stability and operating conditions control strategy in relation to the formation of aerobic granular sludge – a review

Abstract

Currently, research trends on aerobic granular sludge (AGS) have integrated the operating conditions of extracellular polymeric substances (EPS) towards the stability of AGS systems in various types of wastewater with different physical and biochemical characteristics. More attention is given to the stability of the AGS system for real site applications. Although recent studies have reported comprehensively the mechanism of AGS formation and stability in relation to other intermolecular interactions such as microbial distribution, shock loading and toxicity, standard operating condition control strategies for different types of wastewater have not yet been discussed. Thus, the dimensional multi-layer structural model of AGS is discussed comprehensively in the first part of this review paper, focusing on diameter size, thickness variability of each layer and diffusion factor. This can assist in facilitating the interrelation between disposition and stability of AGS structure to correspond to the changes in wastewater types, which is the main objective and novelty of this review. HIGHLIGHTS There is no available standard to describe the size for dimensional multi-layer structural modal of AGS.; Types of bacteria species that dominate the mature AGS depend on the type of wastewater being treated.; Control strategy of operating conditions for AGS system in different type of wastewater.;

Keywords

• aerobic granular sludge
• multi-layer structural model
• operating condition
• sludge stability
• wastewater treatment