Effect of food-to-microorganisms ratio on aerobic granular sludge settleability: Microbial community, potential roles and sequential responses of extracellular proteins and polysaccharides.

The food-to-microorganism ratio (F/M) is an important parameter in wastewater biotreatment that significantly affects the granulation and settleability of aerobic granular sludge (AGS). Hence, understanding the long-term effects and internal mechanisms of F/M on AGS settling performance is essential. This study investigated the relationship between F/M and the sludge volume index (SVI) within a range of 0.