Determination of main components in the extracellular polymeric substances extracted from activated sludge using a spectral probing method

In this study, a spectral probing method was applied to determine the content of the main components, i.e., proteins, polysaccharides and humic substances, in the extracellular polymeric substances (EPS) extracted from activated sludge. The measurement results were consistent with those obtained from the conventional methods, such as the anthrone for polysaccharide determination, the modified Lowry method for protein and humic substance determination. The recoveries for the determination of proteins, humic substances and polysaccharides in the EPS extracted from six sludge samples using standard additional method were between 92.4 and 108.9%, 84.8 and 108.9%, 75.1 and 117.2%, respectively. These results indicate that the propose method has a good accuracy and precision, and can be used as an effective approach to determine the main components in sludge EPS.