Document Type


Publication Date

January 1973


Six proposed rate equations for sorption kinetics have been investigated by laboratory batch experiments involving some 270 individual “runs” to determine sorption uptake with time for varying conditions of initial sorbate concentration, temperature, and sorbent species. The sorbate selected was rhodamine-B dye, used because it will sorb readily and is easily measured. Two sorbents, Dowex 50 resin, and Filtrasorb 200 activated carbon were used. Temperature conditions were 10, 20, 30, and 40°C, and concentrations ranged from .0008 to 400 micrograms per ml, rhodamine-B. Analysis of data was computer automated, requiring as input only test conditions, instrument readings, dilutions, and corresponding time. Output of the program for a “set” of data included three different kinds of plots, determination of Langmuir isotherm constants, carious statistical fits, and calculation of rate coefficients for each of the six proposed rate equations along with commensurate plots and statistical analyses. Results indicated that one rate equation in particular showed high R2 correlations with test data. Further analyses established the rate coefficient for this equation in terms of degree of sorbent saturation with sorbate, sorbate concentration in solutions, and temperature of solution.