Characterization of extracellular polymeric substances (EPS) from phenol degrading aerobic granules

Extracellular polymeric substances (EPS) play essential role in determining efficiencies of sludge bio-granulation processes. Extraction methods and analysis technique on EPS from phenol degrading aerobic granules were examined. High pressure size exclusion chromatography (HPSEC) and excitation–emission matrix (EEM) spectroscopy were used to characterize the EPS extracted from phenol-fed aerobic granules using both physical and chemical extraction protocols. Ultrasound followed by chemical extraction using formaldehyde or formamide with NaOH effectively extracted EPS from aerobic granules of compact interior. The chemical composition, apparent molecular weight and EEM characteristic peaks revealed diverse nature of loosely bound, tightly bound and pellet fractions of the EPS. Chromatographic fingerprints of extracted EPS were compared.