Laboratory-scale assessment of vacuum-degassed activated sludge for improved settling properties

2016 ◽  
Vol 38 (17) ◽  
pp. 2193-2201 ◽  
Author(s):  
Salar Haghighatafshar ◽  
Britt-Marie Wilén ◽  
Andreas Thunberg ◽  
Marinette Hagman ◽  
Annika Nyberg ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Laboratory Scale ◽  
Scale Assessment

Microbiology of activated sludge treating wastewater containing Ni(II) and Cr(VI)

1996 ◽  
Vol 34 (5-6) ◽  
pp. 183-191 ◽  
Author(s):  
Filiz B. Dilek ◽  
Celal F. Gökçay
Keyword(s):  
Activated Sludge ◽  
Bacillus Cereus ◽  
Laboratory Scale ◽  
Pseudomonas Mendocina ◽  
Biochemical Tests ◽  
Arthrobacter Simplex ◽  
Simulated Wastewater ◽  
Acinetobacter Sp

The species of microorganisms dominating a laboratory-scale once-through activated sludge unit treating simulated wastewater with different influent strengths (650 and 1300 mgl−1 COD) and containing 5 to 10 mgl−1 Ni(II) and 1 to 50 mgl−1 Cr(VI) were identified by standard biochemical tests. Within this framework, combinations of metals and influent COD concentrations were tried. Organisms, namely Proteus rettgeri, Acinetobacter sp., Flavobacterium lutescens, Bacillus cereus var. albolactis, Klebsiella sp., Arthrobacter simplex, and Pseudomonas mendocina, were identified at different stages of the experiments.

scholarly journals Transformation of Pristine and Citrate-Functionalized CeO2 Nanoparticles in a Laboratory-Scale Activated Sludge Reactor

2014 ◽  
Vol 48 (13) ◽  
pp. 7289-7296 ◽  
Author(s):  
Lauren E. Barton ◽  
Melanie Auffan ◽  
Marie Bertrand ◽  
Mohamed Barakat ◽  
Catherine Santaella ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Ceo2 Nanoparticles ◽  
Laboratory Scale ◽  
Activated Sludge Reactor

Microbial population dynamics in laboratory-scale activated sludge reactors

2002 ◽  
Vol 46 (1-2) ◽  
pp. 19-27 ◽  
Author(s):  
K. Kaewpipat ◽  
C.P.L. Grady
Keyword(s):  
Activated Sludge ◽  
Microbial Communities ◽  
System Performance ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Treatment Plant ◽  
Laboratory Scale ◽  
Rrna Gene ◽  
Significant Finding ◽  
Prokaryotic Community ◽  
Activated Sludge Systems

As a first step in understanding nonlinear dynamics in activated sludge systems, two laboratory-scale sequencing batch reactors were operated under identical conditions and changes in their microbial communities were followed through microscopic examination, macroscopic observation, and denaturing gradient gel electrophoresis (DGGE) of PCR-amplified 16S rRNA gene segments from the prokaryotic community. Two experiments were performed. The first used activated sludge from a local wastewater treatment plant to start the replicate reactors. The second used the biomass from the first experiment as a source by intermixing the two and equally redistributing the biomass into the two replicate reactors. For both experiments, the two reactors behaved fairly similarly and had similar microbial communities for a period of 60 days following start-up. Beyond that, the microbial communities in the two reactors in the first experiment diverged in composition, while those in the second experiment remained fairly similar. This suggests that the degree of change occurring in replicate reactors depends upon the severity of perturbation to which they are exposed. The DGGE data showed that the bacterial communities in both experiments were highly dynamic, even though the system performance of the replicate reactors were very similar, suggesting that dynamics within the prokaryotic community is not necessarily reflected in system performance. Moreover, a significant finding from this study is that replicate activated sludge systems are not identical, although they can be very similar if started appropriately.

scholarly journals Quinone Profiling of Bacterial Communities in Natural and Synthetic Sewage Activated Sludge for Enhanced Phosphate Removal

1998 ◽  
Vol 64 (3) ◽  
pp. 992-998 ◽  
Author(s):  
Akira Hiraishi ◽  
Yoko Ueda ◽  
Junko Ishihara
Keyword(s):  
Bacterial Community ◽  
Activated Sludge ◽  
Significant Proportion ◽  
Phosphate Removal ◽  
Laboratory Scale ◽  
Operational Mode ◽  
Community Structures ◽  
Sewage Sludges ◽  
Bacterial Populations ◽  
Activated Sludge Processes

ABSTRACT Respiratory quinones were used as biomarkers to study bacterial community structures in activated sludge reactors used for enhanced biological phosphate removal (EBPR). We compared the quinone profiles of EBPR sludges and standard sludges, of natural sewage and synthetic sewage, and of plant scale and laboratory scale systems. Ubiquinone (Q) and menaquinone (MK) components were detected in all sludges tested at molar MK/Q ratios of 0.455 to 0.981. The differences in MK/Q ratios were much larger when we compared different wastewater sludges (i.e., raw sewage and synthetic sewage) than when we compared sludges from the EBPR and standard processes or plant scale and laboratory scale systems. In all sludges tested a Q with eight isoprene units (Q-8) was the most abundant quinone. In the MK fraction, either tetrahydrogenated MK-8 or MK-7 was the predominant type, and there was also a significant proportion of MK-6 to MK-8 in most cases. A numerical cluster analysis of the profiles showed that the sludges tested fell into two major clusters; one included all raw sewage sludges, and the other consisted of all synthetic sewage sludges, independent of the operational mode and scale of the reactors and the phosphate accumulation. These data suggested that Q-8-containing species belonging to the classProteobacteria (i.e., species belonging to the beta subclass) were the major constituents of the bacterial populations in the EBPR sludge, as well as in standard activated sludge. Members of the class Actinobacteria (gram-positive bacteria with high DNA G+C contents) were the second most abundant group in both types of sludge. The bacterial community structures in activated sludge processes may be affected more by the nature of the influent wastewater than by the introduction of an anaerobic stage into the process or by the scale of the reactors.

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