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Prediction of Ion Exchange Equilibrium when Several Cationic Species are Present STUART E. SMITH, Senior Sanitary Engineer Industrial Works Section New York State Department of Health Albany, New York INTRODUCTION In many applications of cation exchange, the system contains more than two exchanging cations. Examples of such systems are water softening, process water treatment, plating bath treatment, and advanced waste treatment. In the latter application, the goal is to produce a potable water from a municipal wastewater treatment plant discharge which has received at least secondary treatment. Depending upon the municipality's industrialization, industrial variety, and effectiveness of the waste treatment process used, the number of cationic species may be quite large. It is readily apparent that in the example applications of ion exchange above, at least three ions are involved (two entering the exchanger and one leaving). A vast literature exists of work done with binary systems (one ion entering the exchanger and one ion leaving). There are very few references to systems of three or more cations (1, 2, 3,4, 5, 6, 7, 8, 9,10,11,12,13,14). Equilibrium sets the limit for the use of any ion exchange process. When the process is at equilibirum, the ion exchanger is said to be "exhausted" and must be regenerated. Besides setting a limit for the amount of material which can be exchanged, equilibirum is important for kinetics. The rate of ion exchange is a function of the departure from equilibirum. When an exchanger is being used to remove more than one cation from a solution flowing through an ion exchange column, it is the emergence of any one cation being removed from the solution which determines when the entire column must be regenerated. The conditions of equilibirum not only determine the amount of exchange which will occur but also which ions are preferred by the exchanger and, therefore, which ion determines the need for regeneration, the indicator ion. In the field of wastewater treatment plant design, it is desirable to use available analytical tools rather than expensive pilot plant operations. If some way could be found to predict behavior of multicomponent ionic systems from the available extensive binary data (15), then considerable simplification would be available for treatment plant design. The system Barium-Copper-Sodium was selected to investigate the prediction of multicationic equilibirum behavior. The three binary systems comprising this ternary system Barium-Copper, Barium-Sodium, and Copper-Sodium had already been investigated (16,17,18) and afforded a check on equilibirum behavior observed in the ternary system. - 932 -
Object Description
Purdue Identification Number | ETRIWC196874 |
Title | Prediction of ion exchange equilibrium when several cationic species are present |
Author | Smith, Stuart E. |
Date of Original | 1968 |
Conference Title | Proceedings of the 23rd Industrial Waste Conference |
Conference Front Matter (copy and paste) | http://earchives.lib.purdue.edu/u?/engext,15314 |
Extent of Original | p. 932-955 |
Series |
Engineering extension series no. 132 Engineering bulletin v. 53, no. 2 |
Collection Title | Engineering Technical Reports Collection, Purdue University |
Repository | Purdue University Libraries |
Rights Statement | Digital object copyright Purdue University. All rights reserved. |
Language | eng |
Type (DCMI) | text |
Format | JP2 |
Date Digitized | 2009-05-20 |
Capture Device | Fujitsu fi-5650C |
Capture Details | ScandAll 21 |
Resolution | 300 ppi |
Color Depth | 8 bit |
Description
Title | page 932 |
Collection Title | Engineering Technical Reports Collection, Purdue University |
Repository | Purdue University Libraries |
Rights Statement | Digital object copyright Purdue University. All rights reserved. |
Language | eng |
Type (DCMI) | text |
Format | JP2 |
Capture Device | Fujitsu fi-5650C |
Capture Details | ScandAll 21 |
Transcript | Prediction of Ion Exchange Equilibrium when Several Cationic Species are Present STUART E. SMITH, Senior Sanitary Engineer Industrial Works Section New York State Department of Health Albany, New York INTRODUCTION In many applications of cation exchange, the system contains more than two exchanging cations. Examples of such systems are water softening, process water treatment, plating bath treatment, and advanced waste treatment. In the latter application, the goal is to produce a potable water from a municipal wastewater treatment plant discharge which has received at least secondary treatment. Depending upon the municipality's industrialization, industrial variety, and effectiveness of the waste treatment process used, the number of cationic species may be quite large. It is readily apparent that in the example applications of ion exchange above, at least three ions are involved (two entering the exchanger and one leaving). A vast literature exists of work done with binary systems (one ion entering the exchanger and one ion leaving). There are very few references to systems of three or more cations (1, 2, 3,4, 5, 6, 7, 8, 9,10,11,12,13,14). Equilibrium sets the limit for the use of any ion exchange process. When the process is at equilibirum, the ion exchanger is said to be "exhausted" and must be regenerated. Besides setting a limit for the amount of material which can be exchanged, equilibirum is important for kinetics. The rate of ion exchange is a function of the departure from equilibirum. When an exchanger is being used to remove more than one cation from a solution flowing through an ion exchange column, it is the emergence of any one cation being removed from the solution which determines when the entire column must be regenerated. The conditions of equilibirum not only determine the amount of exchange which will occur but also which ions are preferred by the exchanger and, therefore, which ion determines the need for regeneration, the indicator ion. In the field of wastewater treatment plant design, it is desirable to use available analytical tools rather than expensive pilot plant operations. If some way could be found to predict behavior of multicomponent ionic systems from the available extensive binary data (15), then considerable simplification would be available for treatment plant design. The system Barium-Copper-Sodium was selected to investigate the prediction of multicationic equilibirum behavior. The three binary systems comprising this ternary system Barium-Copper, Barium-Sodium, and Copper-Sodium had already been investigated (16,17,18) and afforded a check on equilibirum behavior observed in the ternary system. - 932 - |
Resolution | 300 ppi |
Color Depth | 8 bit |
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