Comparison of some characteristics of aerobic granules and sludge flocs from sequencing batch reactors

2007 ◽  
Vol 55 (8-9) ◽  
pp. 403-411 ◽  
Author(s):  
J. Li ◽  
K. Garny ◽  
T. Neu ◽  
M. He ◽  
C. Lindenblatt ◽  
...  
Keyword(s):  
Microbial Activity ◽  
Municipal Wastewater ◽  
Volume Fraction ◽  
Granular Sludge ◽  
Volume Index ◽  
Aerobic Granular Sludge ◽  
Batch Reactors ◽  
Aerobic Granules ◽  
Sequencing Batch Reactors ◽  
Sludge Flocs

Physical, chemical and biological characteristics were investigated for aerobic granules and sludge flocs from three laboratory-scale sequencing batch reactors (SBRs). One reactor was operated as normal SBR (N-SBR) and two reactors were operated as granular SBRs (G-SBR1 and G-SBR2). G-SBR1 was inoculated with activated sludge and G-SBR2 with granules from the municipal wastewater plant in Garching (Germany). The following major parameters and functions were measured and compared between the three reactors: morphology, settling velocity, specific gravity (SG), sludge volume index (SVI), specific oxygen uptake rate (SOUR), distribution of the volume fraction of extracellular polymeric substances (EPS) and bacteria, organic carbon and nitrogen removal. Compared with sludge flocs, granular sludge had excellent settling properties, good solid–liquid separation, high biomass concentration, simultaneous nitrification and denitrification. Aerobic granular sludge does not have a higher microbial activity and there are some problems including higher effluent suspended solids, lower ratio of VSS/SS and no nitrification at the beginning of cultivation. Measurement with CLSM and additional image analysis showed that EPS glycoconjugates build one main fraction inside the granules. The aerobic granules from G-SBR1 prove to be heavier, smaller and have a higher microbial activity compared with G-SBR2. Furthermore, the granules were more compact, with lower SVI and less filamentous bacteria.

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.

Characteristics of Aerobic Granular Sludge Cultivated by Promoting and Inhibiting Filamentous Bacteria

2011 ◽  
Vol 183-185 ◽  
pp. 1075-1079 ◽  
Author(s):  
Shuo Du ◽  
Zhao Hui Zhang ◽  
Yu Feng Zhang ◽  
Pei Chao Jian
Keyword(s):  
Settling Velocity ◽  
Granular Sludge ◽  
Volume Index ◽  
Aerobic Granular Sludge ◽  
Diameter Distribution ◽  
Batch Reactors ◽  
Sequencing Batch Reactors ◽  
Filamentous Bacteria ◽  
Bacteria Growth ◽  
Cultivation Process

Using conventional flocculent activated sludge as seeding sludge, two types of mature aerobic granular sludge were respectively cultivated in the same two sequencing batch reactors (SBR) by promoting and inhibiting filamentous bacteria growth. In R1 reactor the mature aerobic granular sludge was cultivated by promoting filamentous bacteria growth, and the whole cultivation process lasted for 15d. At the same time, another kind of mature aerobic granular sludge was cultivated in R2 reactor by restraining filamentous bacteria growth, and the whole cultivation process lasted for 120d. The comparative analysis showed that the sludge granules produced in R1 reactor had a settling velocity of 45 m/h, SVI (sludge volume index) of 35~45 mL/g, SOUR (sludge oxygen consumption rate) of 1.35 mg/(g•min) and main diameter distribution ranged 2~4 mm; while the sludge granules cultivated in R2 reactor had a settling velocity of 61 m/h, SVI of about 30 mL/g, SOUR of 1.21 mg/(g•min) and main diameter distribution ranged 1~1.6 mm.

scholarly journals Powdered Ceramsite and Powdered Limestone Use in Aerobic Granular Sludge Technology

Materials ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 3894
Author(s):  
Joanna Czarnota ◽  
Janusz A. Tomaszek ◽  
Adam Masłoń ◽  
Adam Piech ◽  
Grzegorz Łagód
Keyword(s):  
Loading Rate ◽  
Granular Sludge ◽  
Aerobic Granular Sludge ◽  
Organic Loading Rate ◽  
Batch Reactors ◽  
Sequencing Batch Reactors ◽  
Sludge Flocs ◽  
Seed Sludge ◽  
The Mean ◽  
Powdered Limestone

The effects of two powdered mineral materials (powdered ceramsite and powdered limestone) on aerobic granulation of sludge were evaluated. The experiment was conducted on a laboratory scale bioreactors treating wastewater for 89 days. Three granular sequencing batch reactors (GSBRs) were operated at the lowest optimal organic loading rate (OLR) of 2.55 g COD/(L∙d). In the control reactor (R1), the mean diameter (d) of the biomass ranged from 124.0 to 210.0 µm, and complete granulation was not achieved. However, complete granulation did occur in reactors to which either ceramsite (251.9 µm < d < 783.1 µm) or limestone (246.0 µm < d < 518.9 µm) was added. Both powdered materials served as a ballast for the sludge flocs making up the seed sludge. Ceramsite particles also acted as microcarriers of granule-forming biomass. The granules in the reactors with added powdered materials had nonfibrous and smoother surfaces. The reactor with ceramsite exhibited the highest average efficiencies for COD, total nitrogen, and total phosphorus removal (85.4 ± 5.4%, 56.6 ± 10.2%, and 56.8 ± 9.9%, respectively). By contrast, the average nitrification efficiency was 95.1 ± 12.8%.

scholarly journals The Impact of Different Powdered Mineral Materials on Selected Properties of Aerobic Granular Sludge

Molecules ◽  
2020 ◽  
Vol 25 (2) ◽  
pp. 386 ◽  
Author(s):  
Joanna Czarnota ◽  
Adam Masłoń ◽  
Monika Zdeb ◽  
Grzegorz Łagód
Keyword(s):  
Extracellular Polymeric Substances ◽  
Granular Sludge ◽  
Biological Properties ◽  
Volume Index ◽  
Aerobic Granular Sludge ◽  
Batch Reactors ◽  
Sequencing Batch Reactors ◽  
Mean Values ◽  
The Impact ◽  
Mg Content

This study aimed to evaluate and compare the physical, chemical and biological properties of aerobic granular sludge from reactors with the addition of different powdered mineral materials. These properties have a significant impact on the efficiency of systems in which the biomass in granular form is used. Four identical granular sequencing batch reactors (GSBRs) were adopted for the research performed on a laboratory scale (R1—control reactor; R2, R3 and R4—with materials, PK, PG and PL respectively). The results indicate that the addition of powdered mineral materials improved the properties of biomass in reactors. The SVI5/SVI30 ratio values were significantly lower in the reactors with added materials (approx. 1.3 ± 0.3). The mean values of the sludge volume index at 30 min were the lowest in the R2 (39.8 ± 8.6 mL/g) and R4 (32.8 ± 10.7 mL/g) reactors. The settling velocity of biomass was the highest in the R2 reactor (15.4 ± 6.1 m/h). In the early days of the study, the highest extracellular polymeric substances (EPS) content was found in the biomass from the reactors to which the materials with higher Ca and Mg content were added (380.18–598.30 mg/g MLVSS). The rate of specific oxygen uptake (SOUR) by biomass indicated an insufficient biomass content in the R1 reactor—to 7.85 mg O2/(g MLVSS∙h)—while in the reactors with materials, the SOUR values were at the higher levels.

scholarly journals Investigation of the influence of Ni(ii) exposure on the simultaneous nitrification and denitrification of aerobic granules from an internal oxygen penetration perspective

RSC Advances ◽  
2017 ◽  
Vol 7 (19) ◽  
pp. 11608-11615 ◽  
Author(s):  
Qian Feng ◽  
Yangyang Yu ◽  
Chong Guo ◽  
Xindi Chen ◽  
Jiashun Cao ◽  
...  
Keyword(s):  
Granular Sludge ◽  
Aerobic Granular Sludge ◽  
Batch Reactors ◽  
Simultaneous Nitrification And Denitrification ◽  
Aerobic Granules ◽  
Sequencing Batch Reactors ◽  
Oxygen Penetration ◽  
Nitrification And Denitrification

Lab-scale Sequencing Batch Reactors (SBR) were adopted to study the effects of Ni(ii) exposure on the simultaneous nitrification and denitrification (SND) of the aerobic granular sludge under different concentrations of Ni(ii) (1.0, 5.0 and 10.0 mg L−1).

scholarly journals Effect of the famine phase length on the properties of aerobic granular sludge treating greywater

2021 ◽  
Author(s):  
U. Rojas-Z ◽  
C. Fajardo-O ◽  
I. Moreno-Andrade ◽  
O. Monroy
Keyword(s):  
Granular Sludge ◽  
High Strength ◽  
Volume Index ◽  
Aerobic Granular Sludge ◽  
Batch Reactors ◽  
Substrate Uptake ◽  
Sequencing Batch Reactors ◽  
Uptake Rates ◽  
Key Factor ◽  
Phase Length

Abstract Sequencing batch reactors (SBR) treating high-strength greywater need an aerobic granular sludge (AGS) with good properties, such as a low sludge volume index (SVI) and high settling velocities and substrate uptake rates to yield short settling and aeration stages. To promote the formation of stable granular sludge, the length of the famine phase could be a key factor. In this regard, the effect of the duration of this variable on the AGS properties was assessed by comparing a gradual versus an abrupt reduction of the famine phase in two SBR treating greywater. The initial average famine phase of 3.3 h was gradually reduced to 0.3 h over 20 weeks in one reactor, and abruptly in another one. This condition induced filamentous outgrowth, as well as the deterioration on the properties of the sludge; being more accelerated the effect when the famine periods were abruptly shortened. In both cases the reduction on the famine periods induced increased organic loading rates, which led to degranulation events when it was higher than 2.5 g-COD g-VSS−1 d−1. Afterwards, the biomass adapted to this situation, by forming new small-filamentous aggregates with similar SVI to that of the stable AGS formed with the longest famine period.

Dissolved oxygen as a key parameter to aerobic granule formation

2008 ◽  
Vol 58 (4) ◽  
pp. 781-787 ◽  
Author(s):  
B. S. McSwain Sturm ◽  
R. L. Irvine
Keyword(s):  
Dissolved Oxygen ◽  
Shear Force ◽  
Granular Sludge ◽  
Aerobic Granular Sludge ◽  
Batch Reactors ◽  
Aerobic Granules ◽  
High Shear ◽  
Sequencing Batch Reactors ◽  
Granule Formation ◽  
Substrate Removal

Much research has asserted that high shear forces are necessary for the formation of aerobic granular sludge in Sequencing Batch Reactors (SBRs). In order to distinguish the role of shear and dissolved oxygen on granule formation, two separate experiments were conducted with three bench-scale SBRs. In the first experiment, an SBR was operated with five sequentially decreasing superficial upflow gas velocities ranging from 1.2 to 0.4 cm s−1. When less than 1 cm s−1 shear was applied to the reactor, aerobic granules disintegrated into flocs, with corresponding increases in SVI and effluent suspended solids. However, the dissolved oxygen also decreased from 8 mg L−1 to 5 mg L−1, affecting the Feast/Famine regime in the SBR and the substrate removal kinetics. A second experiment operated two SBRs with an identical shear force of 1.2 cm s−1, but two dissolved oxygen concentrations. Even when supplied a high shear force, aerobic granules could not form at a dissolved oxygen less than 5 mg L−1, with a Static Fill. These results indicate that the substrate removal kinetics and dissolved oxygen are more significant to granule formation than shear force.

Performance of aerobic granular sludge at variable circulation rate in anaerobic–aerobic conditions

2014 ◽  
Vol 69 (11) ◽  
pp. 2252-2257 ◽  
Author(s):  
Hasnida Harun ◽  
Aznah Nor Anuar ◽  
Zaini Ujang ◽  
Noor Hasyimah Rosman ◽  
Inawati Othman
Keyword(s):  
Municipal Wastewater ◽  
Granular Sludge ◽  
Ammonia Removal ◽  
Soy Sauce ◽  
Volume Index ◽  
Aerobic Granular Sludge ◽  
Circulation Rate ◽  
Anaerobic Conditions ◽  
Aerobic Conditions ◽  
Mixed Liquor

Aerobic granular sludge (AGS) has been applied to treat a broad range of industrial and municipal wastewater. AGS can be developed in a sequencing batch reactor (SBR) with alternating anaerobic–aerobic conditions. To provide anaerobic conditions, the mixed liquor is allowed to circulate in the reactor without air supply. The circulation flow rate of mixed liquor in anaerobic condition is the most important parameter of operation in the anaerobic-AGS processes. Therefore, this study investigates the effect of circulation rate on the performance of the SBR with AGS. Two identical reactors namely R1 and R2 were operated using fermented soy sauce wastewater at circulation rate of 14.4 and 36.0 l/h, respectively. During the anaerobic conditions, the wastewater was pumped out from the upper part of the reactor and circulated back into the bottom of the reactor for 230 min. A compact and dense AGS was observed in both reactors with a similar diameter of 2.0 mm in average, although different circulation rates were adopted. The best reactor performance was achieved in R2 with chemical oxygen demand removal rate of 89%, 90% total phosphorus removal, 79% ammonia removal, 10.1 g/l of mixed liquor suspended solids and a sludge volume index of 25 ml/g.

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