ABSTRACT
This chapter reviews the biodegradability of extracellular polymeric substances (EPS) produced by aerobic granules as well as its contribution to the stability of aerobic granules. P. H. Nielsen, B. Frolund, and K. Keiding investigated the biodegradability of EPS produced from activated sludge during anaerobic storage process. It is apparent that the production of biodegradable EPS should be a common phenomenon broadly existing in a wide spectrum of microorganisms, and also the fraction of biodegradable EPS in the total EPS produced is generally around 50%. To investigate the biodegradation of aerobic granule-associated EPS, fresh aerobic granules taken from a sequencing batch reactor, without pretreatment, were subjected to aerobic starvation without addition of an external carbon source for 20 days. The readily biodegradable EPS can be taken up by aerobic granules at a rate 5 times slower than the biodegradation rate of acetate, but 50 times faster than that of those not readily biodegradable EPS.
