Retention of progesterone by four carbonaceous materials: study of the adsorption kinetics

The process by which progesterone in an ethanol solution is retained by four carbonaceous materials involves a reversible mechanism that conforms to a kinetic equation of unity partial order in both the progesterone concentration in solution, the coverage fraction (theta) of the adsorbing surface and (1 - theta). Over the temperature range 10-40 degreesC, the specific rate constant varies from 5.29 x 10(-4) to 44.85 x 10(-4) s(-1). The formation of the activated species involved in the adsorption process is an endothermal, exoentropic step. The rate of the adsorption-desorption process is primarily determined by diffusion of progesterone molecules in the pores of the sorbent. (C) 2003 Elsevier B.V. All rights reserved.