Biopolymers in Aerobic Granular Sludge—Their Role in Wastewater Treatment and Possibilities of Re-Use in Line with Circular Economy

Abstract

Aerobic granular sludge (AGS) technology for wastewater treatment ensures better quality effluent and higher process sustainability than wastewater treatment systems based on activated sludge. One of the reasons for the better operational results of AGS systems is the high content of extracellular polymers (EPS) in the granule structures. EPS produced during granulation have a very complex composition with a predo minance of polysaccharides and proteins, and one of the main components, alginate, may have a wide variety of practical applications. This review summarizes up-to-date information on the composition of EPS in AGS, the manner in which their production and composition are affected by the operational parameters of wastewater treatment, and the effects of EPS in biomass on wastewater treatment and sludge management. Additionally, the possibility of polymer recovery from AGS is presented together with information regarding potential applications based on the newest findings. Re-use of AGS-derived polymers will increase the sustainability of wastewater treatment processes by making them more economical and reducing the amount of sludge that requires management.

Aerobic Granular Sludge: Perspectives for Excess Sludge Management and Resource Recovery

“…[ [117][118][119] Fire-resistant boards can be produced from EPS-polymers (foam status) [51] The application of EPS-Ps in paper industries can enhances the papers' water resistance properties. [70,110] EPS-ALE can be integrated in several industries, as coating material provides flame retardancy and waterproofness to surfaces or as a potential bio-sorbent for dyes and phosphate.…”

“…Practically, the efficiency of EPS recovery from waste is influenced by several factors such as EPS concentration, type, and extraction methods [79]. Cydzik-Kwiatkowska [51] stated that the extracted substrates from granules can be found in different material forms like liquid, foam, gel and others. de Carvalho et al [54] highlighted that the future of resource recovery focuses mainly on five types of substrates, including biomass, P, cellulose, ALE and bio-plastics.…”

Aerobic Granular Sludge as a Substrate in Anaerobic Digestion—Current Status and Perspectives

“…This can have a significant impact on biogas yields and methane fractions [141]. However, it should be noted that most of the biodegradable fraction of EPS is embedded in the granule interior and core, whereas the surface is mostly composed of structure-forming polymers that are non-biodegradable or hard-to-degrade [166]. The granular interior contains approximately 5 times more EPS than the outer layers [167].…”

Advanced Wastewater Treatment and Biomass Energy

“…Finally, the paper by Cydzik-Kwiatkowska [7] summarizes the possibilities of recovering biopolymers from waste sludge. As a source of biopolymers, aerobic granular sludge (AGS) was analyzed because AGS technology for wastewater treatment ensures better quality effluent and higher process sustainability than wastewater treatment systems based on activated sludge.…”