Modelling the influence of physical properties of extracellular polymeric substances in aerobic granule morphology

This thesis examines the influence of physical properties of structural EPS on granule morphology. Two types of structural EPS are found to be important. These types of structural EPS are: surface bound EPS and hydrogel forming EPS matrix. VirtualLeaf is used to model granules which contain only binding surface bound EPS. The TST model is used...

Variation of Chemical and Structural properties of Waste Aerobic Granular Sludge (WAGS) and Flocculent Sludge in Anaerobic Digestion

A comparative batch experiment as well as a biochemical methane potential(BMP) test were conducted over 44d for aerobic granular sludge (WAGS) and waste flocculent activated sludge(WAS) on sludge anaerobic digestion (AD), to give an insight into the chemical and mechanical properties change of the EPS in different sludge source during AD process...

Strength characterization of full-scale aerobic granular sludge

For a stable operation, the aerobic granular sludge process requires mechanically strong granules in balance with the shear forces in the reactor. Despite a wide general interest in granular stability, the mechanical strength of both anaerobic and aerobic granular sludge received very little attention. In this study, a high-shear method for...

Glycosylated amyloid-like proteins in the structural extracellular polymers of aerobic granular sludge enriched with ammonium-oxidizing bacteria

A new type of structural extracellular polymers (EPS) was extracted from aerobic granular sludge dominated by ammonium-oxidizing bacteria. It was analyzed by Raman and FTIR spectroscopy to characterize specific amino acids and protein secondary structure, and by SDS-PAGE with different stains to identify different glycoconjugates. Its...

The acid soluble extracellular polymeric substance of aerobic granular sludge dominated by Defluviicoccus sp.

A new acid soluble extracellular polymeric substance (acid soluble EPS) was extracted from an acetate fed aerobic granular sludge reactor operated at 35 °C. Acid soluble EPS dominated granules exhibited a remarkable and distinctive tangled tubular morphology. These granules are dominated by Defluviicoccus Cluster II organisms. Acetic acid...

Extraction of structural extracellular polymeric substances from aerobic granular sludge

To evaluate and develop methodologies for the extraction of gel-forming extracellular polymeric substances (EPS), EPS from aerobic granular sludge (AGS) was extracted using six different methods (centrifugation, sonication, ethylenediaminetetraacetic acid (EDTA), formamide with sodium hydroxide (NaOH), formaldehyde with NaOH and sodium...

Sustainable polysaccharide-based biomaterial recovered from waste aerobic granular sludge as a surface coating material

To evaluate the possibility of utilizing polysaccharide-based biomaterial recovered from aerobic granular sludge as a coating material, the morphology, molecular weight distribution and chemical composition of the recovered biomaterial were investigated by atomic force microscopy, size exclusion chromatography and pyrolysis–GC–MS to have a...

Effect and behaviour of different substrates in relation to the formation of aerobic granular sludge

When aerobic granular sludge is applied for industrial wastewater treatment, different soluble substrates can be present. For stable granular sludge formation on volatile fatty acids (e.g. acetate), production of storage polymers under anaerobic feeding conditions has been shown to be important. This prevents direct aerobic growth on readily...

Enhanced digestion and alginate-like-exopolysaccharides extraction from Nereda sludge

Aerobic granular sludge/Nereda technology has proven to be more beneficial compared to activated sludge systems. Until now not much research has been spend on treatment of Nereda excess sludge (NES). In this study the biodegradability of NES is investigated, combined with thermal pressure hydrolysis (TPH) as pre-treatment method and the...

Unravelling the reasons for disproportion in the ratio of AOB and NOB in aerobic granular sludge

In this study, we analysed the nitrifying microbial community (ammonium-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB)) within three different aerobic granular sludge treatment systems as well as within one flocculent sludge system. Granular samples were taken from one pilot plant run on municipal wastewater as well as from two...

Aerobic granular sludge: Scaling up a new technology

Most conventional wastewater treatment plants need a large surface area for the treatment of their sewage. This is due to the open structure of the biomass used to convert the polluting components in wastewater. Because of the flocculated growth, sludge concentrations in reaction tanks are low and settling times need to be long in order to keep...