scholarly journals A new concept of upflow clarification in activated sludge separation

1986 ◽  
Vol 13 (5) ◽  
pp. 517-522
Author(s):  
Arthur B. Sparling ◽  
David L. Woytowich

An experimental investigation was conducted to evaluate a new concept of upflow clarification. A novel sludge removal mechanism that used the entire floor area for the removal of solids was incorporated in an upflow clarifier. The operating characteristics and design features of the continuous flux upflow clarifier (CFLUC) are described in detail. The laboratory study was conducted to determine the effectiveness of the CFLUC clarifier in separating sludges with different settling characteristics. The different sludge types were produced by an activated sludge system treating a synthetic dairy waste at four different food to microorganism (F: M) ratios. At low organic loadings (0.10–0.24 (g COD)(g MLVSS)−1 (d)−1), the CFLUC clarifier removed 70% of the pinpoint floe that remained during quiescent batch settling conditions. At high organic loadings (0.41–0.83 (g COD)(g MLVSS) −1 (d) −1), the CFLUC clarifier was capable of separating filamentous bulking sludges with poor settling characteristics. Based on the results of the experimental study the upflow clarifier effectively separated all sludge types over the range of organic loadings investigated. Key words: CFLUC clarifier, secondary clarification, upflow clarification, sludge blanket, bioflocculation, bulking sludge, gravity sedimentation.

2018 ◽  
Author(s):  
Gede H Cahyana

As a part of activated sludge system, oxidation ditch has a special form like a canal without end point. Rotor is used to diffuse oxygen from air to the water.


1970 ◽  
Vol 5 (1) ◽  
pp. 34-54
Author(s):  
Shyam D. Bokil ◽  
Jatinder K. Bewtra

Abstract Nine sets of batch experiments, each of ten to twelve days duration, were conducted in the laboratory on return-sludge samples collected from activated sludge treatment plant at Windsor. The thickened sludge samples were blended daily in a waring blender and were continuously aerated in twelve-litres capacity jars. Parallel runs were made on control sludge samples which were not blended. Amongst the parameters varied were the speed and frequency of blending and the aeration rate. The effects of these variables on progressive bio-degradation of volatile suspended solids and the settling characteristics of the sludge were determined. Blended sludge showed significant improvement in the rate of bio-degradation and its settling characteristics as compared to the control unblended sludge


1974 ◽  
Vol 9 (1) ◽  
pp. 235-249 ◽  
Author(s):  
S.G. Nutt ◽  
K.L. Murphy

Abstract Conventional wastewater parameters are accepted as inadequate estimates of the condition of activated sludge but numerous other indices have been suggested as specific measurements of the activity and viability of the biomass. Literature in the related fields of microbiology and biochemistry were reviewed in order to select the most appropriate activity parameters for application to a heterogeneous biological material. Modified analytical methods were applied to a well-controlled biological system containing a single predominant bacterial species to evaluate the relative merit of each as an indicator of viability and activity. The potential of each parameter in a complex heterogeneous system was determined by monitoring each index in a bench activated sludge system. The predominant culture studies indicated that the ATP content of the biomass and the dehydrogenase activity were potential indicators of cell viability in a simple system. However, in the complex activated sludge system, only the ATP content showed significant correlation to the organic carbon removal rate.


1994 ◽  
Vol 30 (3) ◽  
pp. 73-78 ◽  
Author(s):  
O. Tünay ◽  
S. Erden ◽  
D. Orhon ◽  
I. Kabdasli

This study evaluates the characterization and treatability of 2,4-D production wastewaters. Wastewaters contain 20000-40000 mg/l COD, 17000-30000 mg/l chloride and pH is around 1.0. Chemical oxidation with hydrogen peroxide provided almost complete COD removal. The optimum conditions are 3:1 H2O2/COD oxidant dosage, 3000 mg/l Fe3+ as catalyst and pH 3. Partial oxidation at 0.5:1 H2O2//COD ratio is also effective providing 67% COD removal. A batch activated sludge system is used for biological treatability. Dilution is needed to maintain a tolerable chloride concentration which increases through COD removal. pH also increased during COD removal. 85% COD removal is obtained for the 50% dilution at an organic loading of 0.3 day‒1 on a COD basis. Completely and partially oxidized wastewaters are also treated in the activated sludge down to 30 mg/l BOD5.


1997 ◽  
Vol 36 (4) ◽  
pp. 307-312
Author(s):  
Michael R. Rasmussen ◽  
Torben Larsen

An on-line settling column for measuring the dynamic variations of settling velocity of activated sludge has been developed. The settling column is automatic and self-cleansing insuring continuous and reliable measurements. The settling column was tested on sludge from a batch reactor where sucrose was added as an impulse to activated sludge. The continuous measurement of settling velocity revealed a highly dynamic response after the sucrose was added. The results were verified with simultaneous measurement of the initial settling rate. A 200 hour experiment showed variations in settling velocity, which was not apparent in the DSVI (Diluted Sludge Volume Index).


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