Retention of Progesterone by an Activated Carbon: Study of the Adsorption Kinetics

The process by which progesterone in an ethanol solution is retained by Merck granular activated carbon involves a reversible mechanism that conforms to a kinetic equation of unity partial order in both the progesterone concentration in solution, the coverage fraction (θ ) of the adsorbing surface and (1−θ ). Over the temperature range 10–40◦C, the specific adsorption rate varies from 5.8·10−5 to 1.3·10−4 s−1. The thermodynamic activation functions for the process are H∗ = 41.6 kJ/mol and S∗ = −0.20 kJ/K· mol. The rate of the adsorption-desorption process is primarily determined by diffusion of progesterone molecules in the pores of the sorbent.