Biological denitrification in a sequencing batch reactor

2004 ◽  
Vol 50 (10) ◽  
pp. 67-72 ◽  
Author(s):  
P. Dangcong ◽  
W. Yi ◽  
W. Hao ◽  
W. Xiaochang
Keyword(s):  
Sequencing Batch Reactor ◽  
Loading Rate ◽  
Batch Reactor ◽  
Granular Sludge ◽  
Filamentous Bacteria ◽  
Microscope Examination ◽  
Biological Denitrification ◽  
Effective Technology ◽  
Nitrate And Nitrite ◽  
Electronic Microscope

Biological denitrification was studied in an SBR to investigate the performance. The experimental results showed that granular sludge with high activity and good settling ability can be developed smoothly in the reactor. With the granular sludge, high nitrate loading rate (0.48 kg NO3-N dm−3 d−1) and removal efficiency (more than 99%) can be achieved. Scanning electronic microscope examination showed that only rod-shape bacteria existed on and within the granules, which confirmed indirectly that filamentous bacteria do not utilize nitrate and nitrite as electron acceptors. SBR is an alternative and effective technology for biological denitrification.

Aerobic granular sludge: a promising technology for decentralised wastewater treatment

2006 ◽  
Vol 53 (9) ◽  
pp. 79-85 ◽  
Author(s):  
Z.H. Li ◽  
T. Kuba ◽  
T. Kusuda
Keyword(s):  
Sequencing Batch Reactor ◽  
Loading Rate ◽  
Batch Reactor ◽  
Granular Sludge ◽  
Volume Index ◽  
Synthetic Wastewater ◽  
Aerobic Granular Sludge ◽  
Organic Loading Rate ◽  
Organic Loading ◽  
Fast Settling

In order to evaluate the characteristics of aerobic granular sludge, a sequencing batch reactor, feeding with synthetic wastewater at the organic loading rate of 8 kg COD/m3 d, was employed on the laboratory scale. Granules occurred in the reactor within 1 week after the inoculation from conventional flocculent sludge. Aerobic granular sludge was characterised by the outstanding settling properties and considerable contaminates removal efficiencies. The SVI30 values were in the range of 20 to 40 ml g−1. However, the sludge volume index of short settling time (e.g. SVI10 – 10 min) is suggested to describe the fast settling properties of aerobic granular sludge. The potential application in the decentralised system is evaluated from the point view of footprint and high bioactivity. The occurrence of sloughing, resulting from the outgrowth of filamentous organisms, would be responsible for the instability of aerobic granules. The starvation phase should therefore be carefully controlled for the maintenance and stability of aerobic granular sludge system.

Effect of Shear Stress on Granulation in Oxygen Aerobic Upflow Sludge Bed Reactors

1992 ◽  
Vol 26 (3-4) ◽  
pp. 601-605 ◽  
Author(s):  
H.-S. Shin ◽  
K.-H. Lim ◽  
H.-S. Park
Keyword(s):  
Shear Stress ◽  
Morphological Study ◽  
Loading Rate ◽  
Granular Sludge ◽  
Treatment Method ◽  
The Self ◽  
High Rate ◽  
Synthetic Wastewater ◽  
Filamentous Bacteria ◽  
Start Up

Aerobic upflow sludge blanket(AUSB) process is a new biological wastewater treatment method applying the concept of the self-immobilization to activated sludge. Two sets of AUSB system with different mixing velocities of 3 rpm(R1) and 6 rpm(R2) were operated for high-rate treatment of synthetic wastewater. The COD removal efficiency in R2 was higher than R1 at the same loading rate up to 7 kg/m3·day. However, in R1, the sludge bulking was observed at the end of the experiment. The chocolate colored granules were formed about 5 days after the start-up. The morphological study on the granular sludge consortia was made with both scanning electron and optical microscopes. The granules were 0.5-2.5 mm in diameter and mainly consisted of bacteria with pili-like appendages and filamentous bacteria, which were thought to be Sphaerotilus natans and Beggiatoa. In R1, the long multicellular filaments causing bulking were prevalent in the granule, while in R2 overgrowth of filamentous bacteria was prevented with appropriate shear stress resulting in higher MLSS density. Experimental results indicated that granulation could be controlled by physical stress on granular sludge.

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.

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.

Adsorption of Cd(ii) from aqueous solution by biogenic selenium nanoparticles

RSC Advances ◽  
2016 ◽  
Vol 6 (18) ◽  
pp. 15201-15209 ◽  
Author(s):  
Fanghui Yuan ◽  
Chao Song ◽  
Xuefei Sun ◽  
Linrui Tan ◽  
Yunkun Wang ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Sequencing Batch Reactor ◽  
High Efficiency ◽  
Batch Reactor ◽  
Granular Sludge ◽  
Selenium Nanoparticles ◽  
Aerobic Granular Sludge ◽  
Biogenic Selenium Nanoparticles

BioSeNPs, which were produced by aerobic granular sludge in a sequencing batch reactor, could be used to remove cadmium from aqueous solution with high efficiency.

Cellulosic waste degradation by rumen-enhanced anaerobic digestion

2003 ◽  
Vol 48 (4) ◽  
pp. 155-162 ◽  
Author(s):  
S.P. Barnes ◽  
J. Keller
Keyword(s):  
Anaerobic Digestion ◽  
Sequencing Batch Reactor ◽  
Loading Rate ◽  
Cellulose Degradation ◽  
Batch Reactor ◽  
Lignocellulosic Material ◽  
Anaerobic Sequencing Batch Reactor ◽  
Microbial Ecosystems ◽  
Cellulosic Waste ◽  
Waste Degradation

Anaerobic digestion of lignocellulosic material is carried out effectively in many natural microbial ecosystems including the rumen. A rumen-enhanced anaerobic sequencing batch reactor was used to investigate cellulose degradation to give analysis of overall process stoichiometry and rates of hydrolysis. The reactor achieved VFA production rates of 207-236 mg COD/L/h at a loading rate of 10 g/L/d. Overloading of the reactor resulted in elevated production of propionic acid, and on occasion, the presence of succinic acid. With improvements in mixing and solids wasting, the anaerobic sequencing batch reactor system could enable full-scale application of the process for treatment of cellulosic waste material.

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