Flotation efficiency of activated sludge flocs using population balance model in dissolved air flotation

2006 ◽  
Vol 23 (2) ◽  
pp. 271-278 ◽  
Author(s):  
Heung-Joe Jung ◽  
Jae-Wook Lee ◽  
Do-Young Choi ◽  
Seong-Jin Kim ◽  
Dong-Heui Kwak
2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Zhenliang Li ◽  
Peili Lu ◽  
Daijun Zhang ◽  
Fuzhong Song

The floc size distribution of activated sludge was simulated successfully by population balance model in the previous study (Population Balance Model and Calibration Method for Simulating the Time Evolution of Floc Size Distribution of Activated Sludge Flocculation. Desalination and Water Treatment, 67, 41-50). However, nonignorable errors exist in the simulation for the volume percentage of large flocs. This paper describes the application of a modified population balance model in the simulation of the time evolution of floc size distribution in activated sludge flocculation process under shear-induced conditions. It was found that the application of modified size dependent collision efficiency, modified breakage rate expression by assuming a maximum value, and binominal daughter-particles distribution function could improve the population balance model for activated sludge flocculation and successfully predict the dynamic changes in volume percentage distribution and mean floc size of activated sludge under different shear conditions. The results demonstrate that the maximum breakage rate was independent on the velocity gradient, and both the collision efficiency and breakage rate coefficient show a power-law relationship with the average velocity gradient; the former decreases while the latter increases with the rise of the average velocity gradient. These findings would help to understand the dynamics of activated sludge flocculation.


2003 ◽  
Vol 47 (1) ◽  
pp. 205-210 ◽  
Author(s):  
P. Jokela ◽  
J. Immonen

Wastewaters from separate chemical factories are treated together in an extended aeration activated sludge plant. The factories produce chemicals for paper industry (e.g. starch), latexes and animal feed. The components of the wastewaters include styrene, tertiary butanol and vinyl acetate. Activated sludge is clarified by sedimentation. During winter time, when the water temperature was 3-12°C, the clarification deteriorated causing carry over of suspended solids containing COD. Enhancement of suspended solids and COD removals was studied in a dissolved air flotation jar test unit. Flotation trials were conducted for activated sludge, sedimentation treated final effluent (tertiary treatment) and separate wastewater fractions. The need for chemicals, flocculation and amount of recycle water were judged according to the achieved removals. Dissolved air flotation was found well suited for the clarification of activated sludge, but not technically and economically feasible for the clarification of the wastewater streams before the activated sludge treatment.


2019 ◽  
Vol 291 ◽  
pp. 121833 ◽  
Author(s):  
Cristina Cagnetta ◽  
Bart Saerens ◽  
Francis A. Meerburg ◽  
Stijn O. Decru ◽  
Eddie Broeders ◽  
...  

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