Cultivation and characteristics of partial nitrification granular sludge in a sequencing batch reactor inoculated with heterotrophic granules

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.

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

Water Science & Technology ◽

10.2166/wst.2012.195 ◽

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.

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

RSC Advances ◽

10.1039/c5ra26367k ◽

2016 ◽

Vol 6 (18) ◽

pp. 15201-15209 ◽

Cited By ~ 15

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.

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