scholarly journals The relationship of biomass to phosphate uptake by Acinetobacter junii in activated sludge mixed liquor

1996 ◽  
Vol 30 (2) ◽  
pp. 364-370 ◽  
Author(s):  
M.N.B. Momba ◽  
T.E. Cloete
Keyword(s):  
Activated Sludge ◽  
Phosphate Uptake ◽  
Acinetobacter Junii ◽  
Mixed Liquor ◽  
Relationship Of ◽  
The Relationship

Particle Size Distribution to the Final Effluent Quality - Based on Turbidity

2013 ◽  
Vol 838-841 ◽  
pp. 1651-1654
Author(s):  
Meng Meng Yin ◽  
He Li Wang ◽  
Chao Yang
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Activated Sludge ◽  
Size Distribution ◽  
Activated Sludge Process ◽  
Effluent Quality ◽  
Mixed Liquor ◽  
Relationship Of ◽  
The Relationship ◽  
Final Effluent

This paper studies the particle size distribution (PSD) and final effluent quality in the activated sludge process. The PSD of final effluent and mixed liquor were determined, and it was found that the settlement in the process can remove particles between 100μm and 200μm easily, while difficult to remove the particles between 13.5μm to 65μm, which was in the supracolloidal (1-100μm) range and could cause problem at higher flows. The final effluent quality was measured by turbidity. The relationship of PSD-10 with turbidity, was analysed and the formed links were paired. Therefore, the PSD can be linked with final effluent quality and can be expected to use as an index to evaluate the final effluent quality future.

Contribution of Pseudomonas spp. to phosphorus uptake in the anoxic zone of an anaerobic-anoxic-aerobic continuous activated sludge system

2001 ◽  
Vol 43 (1) ◽  
pp. 139-146 ◽  
Author(s):  
B. W. Atkinson ◽  
D. D. Mudaly ◽  
F. Bux
Keyword(s):  
Activated Sludge ◽  
Phosphorus Removal ◽  
Phosphate Uptake ◽  
Phosphorus Uptake ◽  
Bulk Liquid ◽  
Anoxic Zone ◽  
Mixed Liquor ◽  
Pseudomonas Spp ◽  
Activated Sludge System ◽  
Polyphosphate Accumulation

A continuously operated laboratory-scale (32 L) nitrification denitrification biological excess phosphorus removal (NDBEPR) activated sludge system (modeled on the 3-stage Phoredox configuration) was maintained for 140 d. The transition from a non-biological excess phosphorus removal (BEPR) sludge to one exhibiting a strong BEPR mechanism was monitored. Mixed liquor seed inoculum was obtained from a full-scale single aerobic activated sludge installation and subjected to conditions conducive to BEPR, i.e. increasing influent acetate (HAc) concentrations. At a sludge age of 10 d with 100% HAc feed, the system was capable of removing a maximum of ca. 40 mgPO4–P/L from the bulk liquid; P/VSS of ca. 0.27 (mgP/mgVSS); and VSS/TSS of 0.53 (mgVSS/mgTSS) in the aerobic zone was attained. Although typical BEPR phosphorus transformation patterns were routinely observed, i.e. anaerobic phosphate release and aerobic phosphate uptake, phosphate uptake in the anoxic zone was also recorded indicating the presence of denitrifying phosphorus accumulating organisms (DPAOs) in the sludge community. The microbial community was screened (using both isolation and direct methods of analysis) for the presence of Pseudomonas spp. as this genus is known to perform both polyphosphate accumulation and denitrification processes. Isolation of anoxic mixed liquor bacteria on solid media and identification using the API 20NE system resulted in the total dominance of the Pseudomonads (>50%). However, direct fluorescent in situ hybridizations (FISH) revealed that Pseudomonas spp. only constituted ca. 3% of the total bacterial community indicating that other bacterial genera are contributing to simultaneous polyphosphate accumulation and denitrification processes in the anoxic zones of NDBEPR systems.

The relationship of the scleractinian corals to the rugose corals

Paleobiology ◽  
1980 ◽  
Vol 6 (02) ◽  
pp. 146-160 ◽  
Author(s):  
William A. Oliver
Keyword(s):  
Critical Points ◽  
Scleractinian Corals ◽  
Convincing Evidence ◽  
Early Triassic ◽  
Rugose Corals ◽  
History Of ◽  
The Subject ◽  
Relationship Of ◽  
The Relationship ◽  
Biologic Factors

The Mesozoic-Cenozoic coral Order Scleractinia has been suggested to have originated or evolved (1) by direct descent from the Paleozoic Order Rugosa or (2) by the development of a skeleton in members of one of the anemone groups that probably have existed throughout Phanerozoic time. In spite of much work on the subject, advocates of the direct descent hypothesis have failed to find convincing evidence of this relationship. Critical points are:(1) Rugosan septal insertion is serial; Scleractinian insertion is cyclic; no intermediate stages have been demonstrated. Apparent intermediates are Scleractinia having bilateral cyclic insertion or teratological Rugosa.(2) There is convincing evidence that the skeletons of many Rugosa were calcitic and none are known to be or to have been aragonitic. In contrast, the skeletons of all living Scleractinia are aragonitic and there is evidence that fossil Scleractinia were aragonitic also. The mineralogic difference is almost certainly due to intrinsic biologic factors.(3) No early Triassic corals of either group are known. This fact is not compelling (by itself) but is important in connection with points 1 and 2, because, given direct descent, both changes took place during this only stage in the history of the two groups in which there are no known corals.

Sign in / Sign up

Export Citation Format

Share Document