Biosynthesis of CdSe Nanoparticles by Anaerobic Granular Sludge

2018 ◽  
pp. 107-130
Author(s):  
Joyabrata Mal
Keyword(s):  
Granular Sludge ◽  
Cdse Nanoparticles ◽  
Anaerobic Granular Sludge

Biosynthesis of CdSe nanoparticles by anaerobic granular sludge

2017 ◽  
Vol 4 (4) ◽  
pp. 824-833 ◽  
Author(s):  
Joyabrata Mal ◽  
Yarlagadda V. Nancharaiah ◽  
Santanu Bera ◽  
Neeraj Maheshwari ◽  
Eric D. van Hullebusch ◽  
...  
Keyword(s):  
Granular Sludge ◽  
Cdse Nanoparticles ◽  
Anaerobic Granular Sludge ◽  
Simultaneous Removal

Simultaneous removal of selenite and cadmium by combining bioremediation of environmentally toxic selenium-rich wastewater with biorecovery of Se as CdSe nanoparticles.

Cadmium selenide formation influences the production and characteristics of extracellular polymeric substances of anaerobic granular sludge

2020 ◽  
Author(s):  
Piet Lens
Keyword(s):  
Cadmium Selenide ◽  
Extracellular Polymeric Substances ◽  
Granular Sludge ◽  
Apparent Molecular Weight ◽  
Repeated Exposure ◽  
Cdse Nanoparticles ◽  
Size Exclusion ◽  
Anaerobic Granular Sludge ◽  
Fluorescence Detector ◽  
Compositional Changes

<p>Feeding cadmium (II) and selenium (IV) simultaneously to anaerobic granular sludge with the aim to synthesize cadmium selenide (CdSe) nanoparticles induces compositional changes in the extracellular polymeric substances (EPS) matrix of this sludge. A methanogenic anaerobic granular sludge was repeatedly exposed to Cd(II) (10-50 mg L<sup>-1</sup>) and selenite (79 mg L<sup>-1</sup>) for 300 days at pH 7.3 and 30 °C in a fed-batch feeding regime for enrichment of Se reducing bacteria and synthesis of CdSe nanoparticles. EPS fingerprints of the granular sludge, obtained by size exclusion chromatography coupled to a fluorescence detector, showed a significant increase in the intensity of protein-like substances with >100 kDa apparent molecular weight (aMW) upon repeated exposure to Cd(II) and Se(VI). This was accompanied by a prominent decrease in protein-like substances of aMW <10 kDa. The fingerprint of the humic-like substances showed emergence of a new peak with aMW of 13 to 300 kDa in the EPS extracted from the Cd/Se fed granular sludge. Experiments on metal(loid)–EPS interactions showed that the CdSe nanoparticles interact mainly with loosely bound-EPS (LB-EPS). This study showed that the formation of Se(0) and CdSe nanoparticles occurs in the LB-EPS fraction of the granular sludge and repeated exposure to Cd and Se induces compositional changes in the EPS matrix.</p>

Toxicity of Sulfite and Cadmium to Anaerobic Granular Sludge

1994 ◽  
Vol 29 (4) ◽  
pp. 581-598
Author(s):  
C.F. Shew ◽  
N. Kosaric
Keyword(s):  
Granular Sludge ◽  
Upflow Anaerobic Sludge Blanket ◽  
Shock Load ◽  
Anaerobic Sludge ◽  
Anaerobic Granular Sludge ◽  
Scanning Electron Micrographs ◽  
Bacterial Growth Rate ◽  
Digestion Rate ◽  
Sulfate Reducing ◽  
Load Conditions

Abstract Toxicity of sulfite (Na2SO3) and cadmium (CdCl2) ions to anaerobic granular sludge was investigated in 1.2 litre bench-scale upflow anaerobic sludge blanket (UASB) reactors during process acclimation and shock load conditions. Minimal sulfite toxicity was observed under gradual and shock load conditions at sulfite concentrations of up to 1000 mg S/L if proper acclimation was allowed to occur. No long-term toxic effects were observed although the COD digestion rate was temporarily inhibited by shock load of sulfite. Scanning electron micrographs indicated that more sulfate-reducing bacteria were present in the granules developed in the reactors with sulfite supplement although rod-shaped Methanosaeta-like bacteria were still dominant. High bacterial growth rate was observed in the reactors which were supplied with the feed containing sulfite. The COD digestion rate was inhibited at a cadmium loading rate of 2.4 g Cd per day under both acclimation and shock load conditions. Acclimation did not seem to improve the bacteria to tolerate the toxicity of cadmium. The concentration of free cadmium was very low in the reactors under normal conditions, but increased rapidly when the COD digestion in the reactors ceased. The bacteria could not be reactivated after inhibited by cadmium. When reactors were operated at low specific COD loading rates, more inorganic precipitates were formed inside the granules which consequently settled faster.

scholarly journals Screening for electrical conductivity in anaerobic granular sludge from full-scale wastewater treatment reactors

2020 ◽  
Vol 159 ◽  
pp. 107575
Author(s):  
Leire Caizán-Juanarena ◽  
Annemiek ter Heijne ◽  
Jan Weijma ◽  
Doekle Yntema ◽  
Diego A. Suárez-Zuluaga ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Wastewater Treatment ◽  
Granular Sludge ◽  
Full Scale ◽  
Anaerobic Granular Sludge

Bioremediation of wastewaters with decabromodiphenyl ether by anaerobic granular sludge

2015 ◽  
Vol 128 ◽  
pp. 522-527 ◽  
Author(s):  
Shou-Qing Ni ◽  
Zhibin Wang ◽  
Lu Lv ◽  
Xueyou Liang ◽  
Longfei Ren ◽  
...  
Keyword(s):  
Granular Sludge ◽  
Anaerobic Granular Sludge ◽  
Decabromodiphenyl Ether

Treatment of Sugar Containing-Low Strength Wastewater at 20°C by Anaerobic Granular Sludge Bed Reactor

2010 ◽  
Vol 5 (3) ◽  
Author(s):  
W. Yoochatchaval ◽  
K. Kubota ◽  
T. Kawai ◽  
T. Yamaguchi ◽  
K. Syutsubo
Keyword(s):  
Stable Process ◽  
Growth Yield ◽  
High Growth ◽  
Granular Sludge ◽  
Post Treatment ◽  
Cod Removal ◽  
Synthetic Wastewater ◽  
Anaerobic Granular Sludge ◽  
Treatment Technology ◽  
Low Strength

To investigate the feasibility of anaerobic wastewater treatment technology for low strength sugar refinery wastewater (0.4 - 0.5 g COD/L), an 8.8 L volume of anaerobic granular sludge bed reactor was operated at 20°C for 400 days. The operation mode was combination of one pass flow (UASB, 50 min) and effluent-recirculation (EGSB, 10 min) mode. The aerobic down-flow hanging sponge (DHS) reactor was installed as a post-treatment. During the started-up period, reactors were fed with synthetic wastewater at overall HRT of 3 hours (anaerobic 2 hours, aerobic 1 hour). After day 85, feed was changed to real wastewater together with supplement of nutrients, trace elements and NaHCO3. The sufficient COD removal efficiency (85% SD±6.2) and stable process performance were elicited from the granular sludge bed reactor.Also, post-treatment (DHS reactor) offered good quality of effluent (45 mg COD/L, 7 mg BOD/L) and it achieved the discharge standard. Increasing of sulfate concentration of wastewater caused higher contribution of sulfate reducing bacteria for COD removal. The sludge concentration and settleability were well maintained thoroughly. However, floatation of large size granule was observed in the later part of experiment. This phenomenon may attribute to the high growth yield of retained sludge at 20°C.

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