Countercurrent plug flow mass exchange with internal particle diffusion

2007 ◽  
Vol 62 (7) ◽  
pp. 2040-2067 ◽  
Author(s):  
Piet J.A.M. Kerkhof
2015 ◽  
Vol 1120-1121 ◽  
pp. 286-290
Author(s):  
Lin Zhang ◽  
Kai Ge liu ◽  
Zhao Wen Zhang ◽  
Yan Liu

Magnetic nano materials were known as high adsorption properties Nano-structural Ni2.33Fe alloy was successfully prepared by hydrothermal method and was used to remove CrO42- ions from aqueous solution. The results show that the equilibrium adsorption quantity increased with the increase of initial CrO42- concentration and pseudo-second-order kinetic models were successfully used for fitting the kinetic data. Webb Maurice diffusion model shows adsorption was controlled by external mass transfer followed by internal particle diffusion mass transfer. And the fitting degree of the Langmuir isotherm and the experimental data was quite high. And the Freundlich isotherm also fitted well.


2018 ◽  
Author(s):  
Nicolette Gan Jia Gui ◽  
Cameron Stanley ◽  
Gary Rosengarten

1971 ◽  
Vol 6 (1) ◽  
pp. 249-272
Author(s):  
P.B. Melynk ◽  
J.D. Norman ◽  
A.W. Wilson

Abstract It is postulated that the mixing conditions in a flow-through reactor can be characterized as having either completely mixed, completely plug flow, or some network of completely mixed and plug flow component vessels. A frequency-response technique is used to obtain an experimental Bodé plot for arbitrarily mixed vessels. The interpretation of the Bodé plot is discussed, and , in light of this interpretation, a network of plug flow and completely mixed components is specified as a flow model. A Rosenbrock search routine is used to improve the parameter estimates of the model. To verify the model, a second order reaction was run through the vessel and the experimentally measured conversion was compared to that predicted by the model. It is shown that the modeling technique, in addition to describing the mixing in the system, will indicate inactive volume, as well as measure the extent of any channeling or short circuiting in the reactor.


1985 ◽  
Vol 17 (2-3) ◽  
pp. 303-311
Author(s):  
Kees de Korte ◽  
Peter Smits

The usual method for OC measurement is the non-steady state method (reaeration) in tapwater or, sometimes, in activated sludge. Both methods are more or less difficult and expensive. The steady state method with activated sludge is presented. Fundamentals are discussed. For complete mixed aeration tanks, plug flow systems with diffused air aeration and carousels the method is described more in detail and the results of measurements are presented. The results of the steady state measurements of the diffused air system are compared with those of the reaeration method in tapwater. The accuracy of the measurements in the 3 systems is discussed. Measurements in other aeration systems are described briefly. It is concluded that the steady state OC measurement offers advantages in comparison with the non-steady state method and is useful for most purposes.


1989 ◽  
Vol 21 (12) ◽  
pp. 1793-1796
Author(s):  
C. P. Crockett ◽  
R. W. Crabtree ◽  
H. R. Markland

The detrimental influence of storm sewer overflows on urban river quality has been widely recognised for many years. One objective of the WRc River Basin Management programme is the development of a river impact model capable of predicting the transient quality changes in receiving waters due to intermittent storm sewage discharges. The production of SPRAT (Spill Pollution Response Assessment Technique) is the first step in the development of such a model. SPRAT incorporates a number of significant simplifications, most notably plug flow and instantaneous mixing, and does not implicitly take into account the effects of dispersion. These simplifications reflect the large errors associated with the model inputs. These errors severely limit the potential accuracy of any river impact model. The model has been applied to the Bolton river system in North West England. The development and application of SPRAT has enabled the requirements for a more sophisticated river quality impact model to be clearly defined, in addition to highlighting the problems associated with gathering suitable data with which to build and calibrate such a model.


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