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

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.

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Metatranscriptome Analysis of Bisphenol A-Exposed Aerobic Granular Sludge

Energies ◽

10.3390/en14113263 ◽

2021 ◽

Vol 14 (11) ◽

pp. 3263

Author(s):

Agnieszka Cydzik-Kwiatkowska ◽

Martyna Grzyb ◽

Piotr Jachimowicz

Keyword(s):

Wastewater Treatment ◽

Bisphenol A ◽

Metabolic Pathways ◽

Control Sample ◽

Granular Sludge ◽

Aerobic Granular Sludge ◽

Illumina Platform ◽

Treatment Processes ◽

Expression Of Genes ◽

Benzoate Degradation

Understanding of the metabolic pathways connected with a removal of micropollutant bisphenol A (BPA) may help to better design effective wastewater treatment processes. The aim of this study was to determine changes in gene expression in an aerobic granular sludge (AGS) community exposed to BPA. In the study, AGS adapted to BPA degradation was used. In this sludge, BPA was dosed; as a control sample, granules without BPA addition were used. mRNA was isolated from both samples and sequenced using the Illumina platform. Metatranscriptome analysis of AGS exposed to BPA indicated direct biodegradation as the main mechanism of BPA removal from wastewater. High expression of genes coding pilus and flagellin proteins in the BPA-exposed biomass indicated that exposition to BPA stimulated aggregation of microbial cells and formation of biofilm. In the BPA-exposed biomass, nitrogen was mainly used as an energy source, as indicated by the presence of genes coding nitrification enzymes and urease. Moreover, exposition to BPA stimulated expression of genes coding proteins responsible for xenobiotic degradation, including enzymes responsible for benzoate degradation. These results increase knowledge about BPA metabolism in complex microbial communities in wastewater treatment systems and indicate that AGS is suitable for efficiently removing BPA from wastewater.

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Performance evaluation of different wastewater treatment technologies operating in a developing country

Journal of Water Sanitation and Hygiene for Development ◽

10.2166/washdev.2011.022 ◽

2011 ◽

Vol 1 (1) ◽

pp. 37-56 ◽

Cited By ~ 16

Author(s):

Sílvia C. Oliveira ◽

Marcos von Sperling

Keyword(s):

Wastewater Treatment ◽

Wastewater Treatment Plants ◽

Septic Tank ◽

Operational Parameters ◽

Technical Literature ◽

Effluent Quality ◽

Loading Rates ◽

Treatment Processes ◽

Treatment Technologies ◽

Uasb Reactors

This article analyses the performance of 166 wastewater treatment plants operating in Brazil, comprising six different treatment processes: septic tank + anaerobic filter, facultative pond, anaerobic pond + facultative pond, activated sludge, UASB reactors alone, UASB reactors followed by post-treatment. The study evaluates and compares the observed effluent quality and the removal efficiencies in terms of BOD, COD, TSS, TN, TP and FC with typical values reported in the technical literature. In view of the large performance variability observed, the existence of a relationship between design/operational parameters and treatment performance was investigated. From the results obtained, no consistent relationship between loading rates and effluent quality was found. The influence of loading rates differed from plant to plant, and the effluent quality was dictated by several combined factors related to design and operation.

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