ABSTRACT
Since the first edition of this manual was published (Jenkins et al., 1984)
much has been learned about factors that affect activated sludge settling characteristics and how to control them
.
It has long been understood that activated sludge settleability is controlled by the physical, chemical, and biological environment of the activated sludge system. The past three decades have seen significant advances in our understanding of the specific factors that control activated sludge settleability and the measures that plant designers and operators can take to achieve better control of sludge settleability. This understanding is useful for resolving activated sludge settling problems in existing systems and for designing new or upgraded plants.
