Selection of slow growing organisms as a means for improving aerobic granular sludge stability

2004 ◽  
Vol 49 (11-12) ◽  
pp. 9-17 ◽  
Author(s):  
M.K. de Kreuk ◽  
M.C.M. van Loosdrecht
Keyword(s):  
Energy Efficient ◽  
Laboratory Experiments ◽  
Wastewater Treatment Plants ◽  
Granular Sludge ◽  
Aerobic Granular Sludge ◽  
Aerobic Granules ◽  
Low Oxygen ◽  
Slow Growing ◽  
Selection Of ◽  
Oxygen Concentrations

Recently, several groups have showed the occurrence of aerobic granular sludge. The excellent settling characteristics of aerobic granular sludge allow the design of very compact wastewater treatment plants. In laboratory experiments, high oxygen concentrations were needed to obtain stable granulation. However, in order to obtain energy efficient aeration and good denitrification low oxygen concentrations would be required. From earlier research on biofilm morphology, it was learned that slow growing organisms influence the density and stability of biofilms positively. To decrease the growth rate of the organisms in the aerobic granules, easily degradable substrate (e.g. acetate) has to be converted to slowly degradable COD like microbial storage polymers (e.g. PHA). Phosphate or glycogen accumulating bacteria perform this conversion step most efficiently. In this paper it is shown that the selection of such bacteria in aerobic granules indeed led to stable granular sludge, even at low oxygen concentrations.

scholarly journals Characterizing the structure of aerobic granular sludge using ultra-high field magnetic resonance

2020 ◽  
Vol 82 (4) ◽  
pp. 627-639
Author(s):  
Catherine M. Kirkland ◽  
Julia R. Krug ◽  
Frank J. Vergeldt ◽  
Lenno van den Berg ◽  
Aldrik H. Velders ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Magnetic Resonance ◽  
Wastewater Treatment Plants ◽  
Granular Sludge ◽  
Structural Features ◽  
Aerobic Granular Sludge ◽  
Aerobic Granules ◽  
Bulk Fluid ◽  
Characterization Methods ◽  
Non Invasive

Abstract Despite aerobic granular sludge wastewater treatment plants operating around the world, our understanding of internal granule structure and its relation to treatment efficiency remains limited. This can be attributed in part to the drawbacks of time-consuming, labor-intensive, and invasive microscopy protocols which effectively restrict samples sizes and may introduce artefacts. Time-domain nuclear magnetic resonance (NMR) allows non-invasive measurements which describe internal structural features of opaque, complex materials like biofilms. NMR was used to image aerobic granules collected from five full-scale wastewater treatment plants in the Netherlands and United States, as well as laboratory granules and control beads. T1 and T2 relaxation-weighted images reveal heterogeneous structures that include high- and low-density biofilm regions, water-like voids, and solid-like inclusions. Channels larger than approximately 50 μm and connected to the bulk fluid were not visible. Both cluster and ring-like structures were observed with each granule source having a characteristic structural type. These structures, and their NMR relaxation behavior, were stable over several months of storage. These observations reveal the complex structures within aerobic granules from a range of sources and highlight the need for non-invasive characterization methods like NMR to be applied in the ongoing effort to correlate structure and function.

Aerobic granular sludge to treat paper mill effluent: selection of ideal strains that contribute to the formation of strong aggregates

2016 ◽  
Vol 57 (59) ◽  
pp. 28537-28550 ◽  
Author(s):  
Ismarley Lage Horta Morais ◽  
Claudio Mudadu Silva ◽  
Antônio Galvão do Nascimento ◽  
Natalino Perovano Filho ◽  
João Carlos Teixeira Dias
Keyword(s):  
Granular Sludge ◽  
Paper Mill ◽  
Aerobic Granular Sludge ◽  
Paper Mill Effluent ◽  
Selection Of

Strength characteristics of aerobic granular sludge

2012 ◽  
Vol 65 (2) ◽  
pp. 309-316 ◽  
Author(s):  
A. Nor-Anuar ◽  
Z. Ujang ◽  
M. C. M. van Loosdrecht ◽  
M. K. de Kreuk ◽  
G. Olsson
Keyword(s):  
Granular Sludge ◽  
Aerobic Granular Sludge ◽  
Strength Analysis ◽  
Anaerobic Granular Sludge ◽  
Aerobic Granules ◽  
Sludge Flocs ◽  
Conventional Activated Sludge ◽  
Biomass Retention ◽  
Settling Characteristic ◽  
Fast Settling

Aerobic granular sludge has a number of advantages over conventional activated sludge flocs, such as cohesive and strong matrix, fast settling characteristic, high biomass retention and ability to withstand high organic loadings, all aspects leading towards a compact reactor system. Still there are very few studies on the strength of aerobic granules. A procedure that has been used previously for anaerobic granular sludge strength analysis was adapted and used in this study. A new coefficient was introduced, called a stability coefficient (S), to quantify the strength of the aerobic granules. Indicators were also developed based on the strength analysis results, in order to categorize aerobic granules into three levels of strength, i.e. very strong (very stable), strong (stable) and not strong (not stable). The results indicated that aerobic granules grown on acetate were stronger (high density: >150 g T SSL−1 and low S value: 5%) than granules developed on sewage as influent. A lower value of S indicates a higher stability of the granules.

The SBR and its biofilm application potentials

2004 ◽  
Vol 50 (10) ◽  
pp. 1-10 ◽  
Author(s):  
P.A. Wilderer ◽  
B.S. McSwain
Keyword(s):  
Activated Sludge ◽  
Batch Reactor ◽  
Granular Sludge ◽  
Aerobic Granular Sludge ◽  
Waste Streams ◽  
Sludge Flocs ◽  
Biofilm Reactors ◽  
Volatile Organic ◽  
High Level ◽  
Slow Growing

Twenty plus years of experience, innovation, and research in the field of biological wastewater treatment and biofilm applications lead to the conclusion that biofilms are in many cases more desirable in reactors than suspended activated sludge. Biofilm reactors can provide very long biomass residence times even when the hydraulic influent loading is low. This makes them particularly suitable when treatment requires slow growing organisms with poor biomass yield or when the wastewater concentration is too low to support growth of activated sludge flocs. Regardless of the settling characteristics of biological aggregates or the hydraulic influent loading the metabolic activity in the reactor can be maintained at a high level. This paper reviews the application of biofilms in sequencing batch reactor (SBR) systems to treat non-readily biodegradable substrates, volatile organic waste constituents, complex waste streams requiring co-metabolism, and particulate wastewaters. Recent research using the SBR to form aerobic granular sludge as a special application of biofilms is also discussed.

scholarly journals Simultaneous nitrification and phosphate removal by bioaugmented aerobic granules treating a fluoroorganic compound

2021 ◽  
Author(s):  
Anouk F. Duque ◽  
Vânia S. Bessa ◽  
Udo van Dongen ◽  
Merle K. de Kreuk ◽  
Raquel B. R. Mesquita ◽  
...  
Keyword(s):  
Denaturing Gradient Gel Electrophoresis ◽  
Amoa Gene ◽  
Granular Sludge ◽  
Phosphate Removal ◽  
Aerobic Granular Sludge ◽  
Ammonia Oxidizing Bacteria ◽  
Aerobic Granules ◽  
N Removal ◽  
Nitrite Oxidizing Bacteria ◽  
Gradient Gel Electrophoresis

Abstract The presence of toxic compounds in wastewater can cause problems for organic matter and nutrient removal. In this study, the long term effect of a model xenobiotic, 2-fluorophenol (2-FP), on ammonia oxidizing bacteria (AOB), nitrite oxidizing bacteria (NOB) and phosphate accumulating organisms (PAO) in aerobic granular sludge was investigated. Phosphate (P) and ammonium (N) removal efficiencies were high (>93%) and, after bioaugmentation with 2-FP degrading strain FP1, 2-FP was completely degraded. Neither N nor P removal were affected by 50 mg L−1 of 2-FP in the feed stream. Changes in the aerobic granule bacterial communities were followed. Numerical analysis of the denaturing gradient gel electrophoresis (DGGE) profiles showed low diversity for the amoA gene with an even distribution of species. PAOs, including denitrifying PAO (dPAO), and AOB were present in the 2-FP degrading granules, although dPAO population decreased throughout the 444 days reactor operation. The results demonstrated that the aerobic granules bioaugmented with FP1 strain successfully removed N, P and 2-FP simultaneously.

scholarly journals Study on aerobic granular sludge formation in sequencing batch reactors for tapioca wastewater treatment

2013 ◽  
Vol 16 (1) ◽  
pp. 40-48
Author(s):  
Phuong Thi Thanh Nguyen ◽  
Phuoc Van Nguyen ◽  
Anh Cam Thieu
Keyword(s):  
Granular Sludge ◽  
Biomass Accumulation ◽  
Synthetic Wastewater ◽  
Aerobic Granular Sludge ◽  
Organic Loading Rate ◽  
Anaerobic Sludge ◽  
Batch Reactors ◽  
Aerobic Granules ◽  
Toxic Substances ◽  
Sequencing Batch Reactors

Aerobic granular sludge has attracted extensive interest of researchers since the 90s due to the advantages of aerobic granules such as good settling ability, high biomass accumulation, being resistant to high loads and being less affected by toxic substances. Studies, however, which have mainly been carried out on synthetic wastewater, cannot fully evaluate the actual ability of aerobic granules. Study on aerobic granular sludge was performed in sequencing batch reactors, using seeding sludge taken from anaerobic sludge and tapioca wastewater as a substrates. After 11 weeks of operation, the granules reached the stable diameter of 2- 3 mm at 3.7 kgCOD/m3.day organic loading rate. At high organic loads, in range of 1.6 - 5 kgCOD/m3.day, granules could treat effectively COD, N, P with performance of 93 – 97%; 65 – 79% and 80 – 95%, respectively.

Aerobic granulation

2000 ◽  
Vol 41 (4-5) ◽  
pp. 41-48 ◽  
Author(s):  
J.J. Beun ◽  
M.C. van Loosdrecht ◽  
J.J. Heijnen
Keyword(s):  
Loading Rate ◽  
Bubble Column ◽  
Granular Sludge ◽  
Aerobic Granular Sludge ◽  
Process Conditions ◽  
Dense Granules ◽  
Steady State Operation ◽  
Mixing Intensity ◽  
Selection Of

Heterotrophic aerobic granular sludge was cultivated in a sequencing batch airlift reactor (SBAR). A steady state operation, at a COD loading of 2.3 kg COD/(m3· d), was run for 50 days after which the experiment was terminated. The granules obtained were smooth, 1.0 mm in diameter and had a density of 48 g/l. Selection of dense granules occurred by applying a short settling time. Slow settling s ludge was washed out with the effluent and only the granules with good settling properties settled fast enough (vmin>16.2 m/h) to be retained in the reactor. Nitrification and almost complete denitrification occurred in the fully aerobic SBAR without any optimization of the process conditions. Compared to a sequencing batch bubble column (SBBC) much more dense granules with a smaller diameter were obtained in the SBAR at the same substrate loading rate and the same mixing intensity. Compared to granules formed in a, continuous fed, biofilm airlift suspension (BAS) reactor much more dense granules were obtained in the SBAR as well. The diameter of the granules in the BAS reactor was smaller than in the SBAR. Possible reasons for the better quality of the sludge granules in the SBAR are discussed.

scholarly journals Performance Evaluation of Continuous Flow Aerobic Granular Sludge Configurations

2019 ◽  
Vol 70 (1) ◽  
pp. 283-285
Author(s):  
Elena Elisabeta Manea ◽  
Costel Bumbac
Keyword(s):  
Wastewater Treatment ◽  
Continuous Flow ◽  
High Efficiency ◽  
Wastewater Treatment Plants ◽  
Granular Sludge ◽  
Synthetic Wastewater ◽  
Aerobic Granular Sludge ◽  
Batch Reactors ◽  
Nutrients Removal ◽  
Flow Configurations

Increasing the efficiency and capacity of existing wastewater treatment plants can be carried out by using intensive biological processes. One of the currently studied biological solutions consists in using aerobic granular sludge in order to achieve both organics and nutrients removal simultaneously in one tank and with high efficiency. Aerobic granular sludge is currently used at full scale in sequential batch reactors, research for identifying the optimal solutions for continuous flow systems being carried out worldwide. The paper summarizes the results obtained for two continuous flow configurations with aerobic granular sludge, in terms of organics and nutrients removal for synthetic wastewater in laboratory conditions. Both experimental setups led to wastewater treatment efficiencies, with values ranging between 80 and 99% for COD, 85 and 99% for BOD5, 52 and 98% for NH4+ and 5 to 87% for TP.

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