Effects of extracellular polymeric substances on granulation of anoxic sludge in sequencing batch reactor

2012 ◽  
Vol 66 (3) ◽  
pp. 543-548
Author(s):  
Binbin Wang ◽  
Shunlian Liu ◽  
Hongmei Zhao ◽  
Xinyan Zhang ◽  
Dangcong Peng
Keyword(s):  
Extracellular Polymeric Substances ◽  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Cation Exchange Resin ◽  
Granular Sludge ◽  
Extracellular Proteins ◽  
Extracellular Polysaccharides ◽  
Positive Role ◽  
Start Up ◽  
Sludge Granulation

Variations of extracellular polymeric substances (EPS) and its components with sludge granulation were examined in a lab-scale sequencing batch reactor (SBR) which was fed with sodium nitrate and sodium acetate. Ultrasonication plus cation exchange resin (CER) were used as the EPS extraction method. Results showed that after approximately 90 d cultivation, the sludge in the reactor was almost granulated. The content of extracellular polysaccharides increased from 10.36 mg/g-VSS (volatile suspended solids) at start-up with flocculent sludge to 23.18 mg/g-VSS at 91 d with matured granular sludge, while the content of extracellular proteins were almost unchanged. Polysaccharides were the major components of EPS in anoxic granular sludge, accounting for about 70.6–79.0%, while proteins and DNA accounted for about 16.5–18.9% and 4.6–9.9%, respectively. It is proposed that EPS play a positive role in anoxic sludge granulation and polysaccharides might be strongly involved in aggregation of flocs into granules.

Start-up of an aerobic granular sequencing batch reactor for the treatment of winery wastewater

2009 ◽  
Vol 60 (4) ◽  
pp. 1049-1054 ◽  
Author(s):  
S. López–Palau ◽  
J. Dosta ◽  
J. Mata-Álvarez
Keyword(s):  
Organic Matter ◽  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Particle Diameter ◽  
Granular Sludge ◽  
Average Density ◽  
Aerobic Granular Sludge ◽  
Organic Load ◽  
Winery Wastewater ◽  
Start Up

Aerobic granular sludge was cultivated in a sequencing batch reactor (SBR) in order to remove the organic matter present in winery wastewater. The formation of granules was performed using a synthetic substrate. The selection parameter was the settling time, as well as the alternation of feast-famine periods, the air velocity and the height/diameter ratio of the reactor. After 10 days of operation under these conditions, the first aggregates could be observed. Filamentous bacteria were still present in the reactor but they disappeared progressively. During the start-up, COD loading was increased from 2.7 to 22.5 kg COD/(m3 day) in order to obtain a feast period between 30 and 60 minutes. At this point, granules were quite round, with a particle diameter between 3.0 and 4.0 mm and an average density of 6 g L−1. After 120 days of operation, synthetic media was replaced by real winery wastewater, with a COD loading of 6 kg COD/(m3 day). The decrease of the organic load implied a reduction of the aggregate diameter and a density increase up to 13.2 g L−1. The effluent was free of organic matter and the solids concentration in the reactor reached 6 g VSS L−1.

scholarly journals Aerobic Sludge Granulation in a Full-Scale Sequencing Batch Reactor

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Jun Li ◽  
Li-Bin Ding ◽  
Ang Cai ◽  
Guo-Xian Huang ◽  
Harald Horn
Keyword(s):  
Extracellular Polymeric Substances ◽  
Sequencing Batch Reactor ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Batch Reactor ◽  
Treatment Plant ◽  
Full Scale ◽  
Granule Formation ◽  
Sludge Granulation ◽  
Aerobic Sludge ◽  
Raw Wastewater

Aerobic granulation of activated sludge was successfully achieved in a full-scale sequencing batch reactor (SBR) with 50,000 m3 d−1for treating a town’s wastewater. After operation for 337 days, in this full-scale SBR, aerobic granules with an average SVI30of 47.1 mL g−1, diameter of 0.5 mm, and settling velocity of 42 m h−1were obtained. Compared to an anaerobic/oxic plug flow (A/O) reactor and an oxidation ditch (OD) being operated in this wastewater treatment plant, the sludge from full-scale SBR has more compact structure and excellent settling ability. Denaturing gradient gel electrophoresis (DGGE) analysis indicated thatFlavobacteriumsp., uncultured beta proteobacterium, unculturedAquabacteriumsp., and unculturedLeptothrixsp. were just dominant in SBR, whereas uncultured bacteroidetes were only found in A/O and OD. Three kinds of sludge had a high content of protein in extracellular polymeric substances (EPS). X-ray fluorescence (XRF) analysis revealed that metal ions and some inorganics from raw wastewater precipitated in sludge acted as core to enhance granulation. Raw wastewater characteristics had a positive effect on the granule formation, but the SBR mode operating with periodic feast-famine, shorter settling time, and no return sludge pump played a crucial role in aerobic sludge granulation.

Cultivation of polyhydroxybutyrate-rich aerobic granular sludge in a sequencing batch reactor

2006 ◽  
Vol 6 (6) ◽  
pp. 81-87 ◽  
Author(s):  
J. Wang ◽  
H.Q. Yu
Keyword(s):  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Granular Sludge ◽  
Volume Index ◽  
Synthetic Wastewater ◽  
Aerobic Granular Sludge ◽  
Second Step ◽  
Sludge Volume Index ◽  
Flat Shape ◽  
Sludge Granulation

In this study a two-step strategy was adopted to cultivate Polyhydroxybutyrate (PHB)-rich aerobic granular sludge in a sequencing batch reactor (SBR) fed with a synthetic wastewater. In the first step both oxygen and ammonia were initially limited, in order to enhance the PHB-storage ability of sludge. In the second step granular sludge was cultivated to get a high PHB volumetric productivity. The PHB content of sludge increased to 43.1±2.0% in the first step. During the sludge granulation, the PHB content was constant at 40±4.6%. With the granulation, the settling ability of the PHB-rich sludge continuously improved, as evidenced by a decreased sludge volume index. The matured PHB-rich granular sludge presented a buff color and regular morphology with elliptical and flat shape.

The influence of settling time on the formation of aerobic granules

2004 ◽  
Vol 50 (10) ◽  
pp. 195-202 ◽  
Author(s):  
B.S. McSwain ◽  
R.L. Irvine ◽  
P.A. Wilderer
Keyword(s):  
Shear Force ◽  
Batch Reactor ◽  
Cation Exchange Resin ◽  
Granular Sludge ◽  
Community Analysis ◽  
Settling Time ◽  
Aerobic Granular Sludge ◽  
Extracellular Polysaccharides ◽  
Aerobic Granules ◽  
Pcr Products

Aerobic granular sludge, without the addition of carrier material, has only been reported in one suspended growth system, the Sequencing Batch Reactor (SBR) operated with short fill and settling periods. Recent studies have demonstrated that extracellular polysaccharides increased with the formation of aerobic granules, and that the shear force may stimulate production of these polysaccharides. In the study described herein, two SBRs were operated with the same shear force (air flow rate 275 L h−1) and two different settling times (2 and 10 min). Only the reactor with 2 min settling formed completely granular sludge, although granules were present in both reactors. Community analysis using 16S rRNA PCR products and DGGE showed that the communities diverged quickly after reactor start-up. For samples taken at steady-state, the granular population was more stable and less diverse than the flocculent reactor. EPS extraction of samples using cation exchange resin yielded similar values for aerobic granular sludge and previously reported anaerobic granules. While differences in the protein and TOC content between the flocculent and granular reactors increased appreciably as the sludge became more granular, the protein to polysaccharide ratio was relatively constant. The experiment confirmed previous theories that short settling times in SBRs select for granular sludge. The settling time results in granular sludge having a higher EPS protein content and a less diverse but more stable population.

Biodegradation of Paracetamol by Aerobic Granules in a Sequencing Batch Reactor (SBR)

2012 ◽  
Vol 441 ◽  
pp. 531-535 ◽  
Author(s):  
Jun Hu ◽  
Lan Zhou ◽  
Qing Wei Zhou ◽  
Fang Wei ◽  
Li Li Zhang ◽  
...  
Keyword(s):  
Degradation Rate ◽  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Substrate Inhibition ◽  
Energy Resource ◽  
Granular Sludge ◽  
Aerobic Granules ◽  
Dominant Form ◽  
Start Up ◽  
Insight Into

Aerobic granules efficient at degrading paracetamol as the sole carbon and energy resource were successfully developed in a sequencing batch reactor (SBR). Aerobic granules were first observed about 220 days after reactor start-up. The images SEM showed the aerobic granules typically consisted of coccus and bacillus. Meanwhile, the size distribution of aerobic granules was analyzed on day 200. The result indicated that the granules eventually grew to become the dominant form of biomass in the reactor. The granular sludge on day 80 and 200 degraded paracetamol completely in 48 h and 28 h, respectively, indicating that granulation contributed to paracetamol degradation. The specific paracetamol degradation rate was observed to increase with increasing paracetamol initial concentration from 500 to 5000 mg/L, peaked at 1200 mg-MTBE/g-VSS·h, and declined with further increases in MTBE concentration as substrate inhibition effects became significant. This study demonstrates that paracetamol can be effectively degraded by aerobic granules and gives insight into the microorganisms potentially involved in the process.

Start-up of a granular sludge sequencing batch reactor for the treatment of 2,4-dichlorophenol-contaminated wastewater

2013 ◽  
Vol 68 (10) ◽  
pp. 2151-2157 ◽  
Author(s):  
S. Milia ◽  
R. Porcu ◽  
S. Rossetti ◽  
A. Carucci
Keyword(s):  
Sequencing Batch Reactor ◽  
Gradual Increase ◽  
Batch Reactor ◽  
Scale Up ◽  
Granular Sludge ◽  
Operating Conditions ◽  
Loading Rates ◽  
Start Up ◽  
Phase Cycle

In this study, a granular sludge sequencing batch reactor (GSBR) was started-up for the biological aerobic treatment of wastewater containing highly toxic 2,4-dichlorophenol (2,4-DCP), in presence of readily biodegradable sodium acetate (NaAc) as the growth substrate. Different influent concentrations of NaAc (420–800 mg/L) and 2,4-DCP (0–20 mg/L), as well as different operating conditions (i.e. cycle length), were tested in order to determine the optimal strategy for successful GSBR start-up: stable granulation and complete 2,4-DCP removal were achieved only when high NaAc influent concentration and volumetric organic loading rates (800 mg/L and 1.9 kgCOD/(m3·d), respectively), prolonged reaction phase (cycle time of 4 hours) and gradual increase of 2,4-DCP concentration in the influent were applied, thus providing useful information for process optimization in view of future scale-up. Granules were initially colonized by fungi which progressively disappeared during the start-up process, and complete 2,4-DCP removal was mostly due to bacterial activity, in particular Betaproteobacteria, as shown by fluorescence in situ hybridization (FISH).

The key role of inoculated sludge in fast start-up of sequencing batch reactor for the domestication of aerobic granular sludge

2019 ◽  
Vol 78 ◽  
pp. 127-136 ◽  
Author(s):  
Xiao-chun Wang ◽  
Zhong-lin Chen ◽  
Jing Kang ◽  
Xia Zhao ◽  
Ji-min Shen ◽  
...  
Keyword(s):  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Granular Sludge ◽  
Aerobic Granular Sludge ◽  
Start Up ◽  
Fast Start
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