| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 4482515 | Water Research | 2013 | 9 Pages |
This study aimed to investigate differences in the gel matrix of aerobic granular sludge and normal aerobic flocculent sludge. From both types of sludge that fed with the same municipal sewage, the functional gel-forming exopolysaccharides, alginate-like exopolysaccharides, were isolated. These two exopolysaccharides were chemically fractionated, and investigated by FT-IR spectroscopy. The isolated polymers were made into a gel by calcium addition and the mechanical properties of these reconstituted gels were measured by a low load compression tester. The viscoelastic behavior of the gels was described by a generalized Maxwell model. The alginate-like exopolysaccharides derived from aerobic granules had significantly higher amount of poly(guluronic acid) blocks but lower amount of poly(guluronic acid-manuronic acid) blocks in the chemical structure, while the alginate-like exopolysaccharides derived from aerobic flocculent sludge had equal amount of poly(guluronic acid) blocks and poly(guluronic acid-manuronic acid) blocks. These differences result in a perfect gel-forming capability of alginate-like exopolysaccharides derived from aerobic granules and bestowed this exopolysaccharides gel a stronger mechanical property as compared to alginate-like exopolysaccharides derived from aerobic flocculent sludge. The different chemical and mechanical properties of these two exopolysaccharides contributed to the distinguished characteristics between aerobic granular sludge and aerobic flocculent sludge.
Graphical abstractFigure optionsDownload full-size imageDownload high-quality image (111 K)Download as PowerPoint slideHighlights► Alginate-like EPS exist in both aerobic flocculent and granular sludge. ► Ca-alginate-like EPS gels reflect the morphologies of flocs and granules. ► Chemical structures of alginate-like EPS from flocs and granules are different. ► Alginate-like EPS gel derived from aerobic granules is mechanically stronger.
