THE MIXED-BED ION EXCHANGE PERFORMANCE AT ULTRALOW CONCENTRATIONS

Noh BI; Yoon TK; Moon BH

Korean Journal of Chemical Engineering, Vol.13, No.2, 150-158, March, 1996

Experimental data were obtained to evaluate the performance of mixed-bed on exchange for the cases of variable feed concentration and incomplete mixing of anion and cation resins observed in large scale industrial units. For variable feed concentration, step changes in feed concentration were arbitrarily introduced into a test column. For incomplete mixing, only anion resin was loaded in the upper 20% of the column and more cation resin in the lower portion. Feed concentrations of 5.0×10^-5-2.0×10^-4M NaCl were used for the experiments, with flow rates of 0.665-7.0ml/sec. The effluent from the column was collected periodically and analyzed using on-line/off-line ion chromatography. The step changes in feed concentration affect the breakthrough times of sodium and chloride. Sodium breakthrough curve is more sensitive to the step changes than chloride breakthrough curve. With the same volumes of cation and anion resins, incomplete mixing of resins increases the cation exchange rate slightly and decreases the anion exchange rate slightly. As the cation resin Volume increases, the effect of the incomplete mixing of resins decreases. The breakthrough curves of both ions, plotted as the ratio of effluent to the influent concentration versus run time in hour, give some detailed results about the effects of the conditions.

Keywords:(Mixed-Bed) Ion Exchange;Ultrapure Water;Ultralow Concentrations;Resin;Breakthrough

[References]

Divekar SV, Foutch GL, Haub CU, Ind. Eng. Chem. Res., 26(9), 1906 (1987)
Dowex, "Dowex: Ion Exchange," The Dow Chemical Company, Midland, Michigan (1958)
Grammont P, Rothschild W, Katsahian J, "Ion Exchange: Science and Technology," NATO Advanced Science Institutes Series, Martinus Nijhoff Publishers (1986)
Harries RR, "The Role of pH in Ion Exchange Kinetics," in "Ion Exchange for Industry," Ellis Horwood Limited, Chichester, England (1988)
Haub CE, Foutch GL, Ind. Eng. Chem. Fundam., 25(3), 373 (1986)
Haub CE, Foutch GL, Ind. Eng. Chem. Fundam., 25(3), 381 (1986)
Helfferich F, "Ion Exchange," McGraw-Hill Book Company, New York (1962)
Helfferich F, J. Phys. Chem., 67(4), 1178 (1965)
Kunin R, McGarvey FX, Ind. Eng. Chem. Process Des. Dev., 43(3), 734 (1951)
King DW, "The Influence of Temperature and Amines on Mixed-Bed Ion Exchange Column Performance for Ultra-Low Concentrations of Sodium and Chloride," Ph.D. Dissertation, Oklahoma State University, Stillwater, Oklahoma (1991)
Yoon T, Moon BH, Noh BI, HWAHAK KONGHAK, 33(1), 121 (1995)
Zecchini EJ, "Solutions to Selected Problems in Multicomponent Mixed-Bed Ion Exchange Modeling," Ph.D. Dissertation, Oklahoma State University, Stillwater, Oklahoma (1990)

[Referenced By]

[1] Divekar SV, Foutch GL, Haub CU, Ind. Eng. Chem. Res., 26(9), 1906 (1987)

[2] Dowex, "Dowex: Ion Exchange," The Dow Chemical Company, Midland, Michigan (1958)

[3] Grammont P, Rothschild W, Katsahian J, "Ion Exchange: Science and Technology," NATO Advanced Science Institutes Series, Martinus Nijhoff Publishers (1986)

[4] Harries RR, "The Role of pH in Ion Exchange Kinetics," in "Ion Exchange for Industry," Ellis Horwood Limited, Chichester, England (1988)

[5] Haub CE, Foutch GL, Ind. Eng. Chem. Fundam., 25(3), 373 (1986)

[6] Haub CE, Foutch GL, Ind. Eng. Chem. Fundam., 25(3), 381 (1986)

[7] Helfferich F, "Ion Exchange," McGraw-Hill Book Company, New York (1962)

[8] Helfferich F, J. Phys. Chem., 67(4), 1178 (1965)

[9] Kunin R, McGarvey FX, Ind. Eng. Chem. Process Des. Dev., 43(3), 734 (1951)

[10] King DW, "The Influence of Temperature and Amines on Mixed-Bed Ion Exchange Column Performance for Ultra-Low Concentrations of Sodium and Chloride," Ph.D. Dissertation, Oklahoma State University, Stillwater, Oklahoma (1991)

[11] Yoon T, Moon BH, Noh BI, HWAHAK KONGHAK, 33(1), 121 (1995)

[12] Zecchini EJ, "Solutions to Selected Problems in Multicomponent Mixed-Bed Ion Exchange Modeling," Ph.D. Dissertation, Oklahoma State University, Stillwater, Oklahoma (1990)