Solvent adsorption Freundlich equation

For separation by adsorption, adsorption capacity is often the most important parameter because it determines how much adsorbent is required to accomplish a certain task. For the adsorption of a variety of antibiotics, steroids, and hormons, the adsorption isotherm relating the amount of solute bound to solid and that in solvent can be described by the empirical Freundlich equation. 

As discussed in 17.1.2.4., adsorption by soil components can remove solvents dissolved in water. Furthermore, the rate of movement of dissolved solvents through soil may be retarded by adsorption-desorption reactions between the solvents and the solid phases. The partitioning of solvents between the liquid phase and soil is usually described by an adsorption isotherm. The adsorption of solvents may be described by the Freundlich Equation ... 

For many technologists the prime use of the BET Equation is to characterize an adsorbent for gases by estimating its total surface area available for adsorption (Box A2.2). This cannot be done directly with either the Langmuir or Freundlich equations because they are denominated in the amount of activated sites, and not in the volume of solvent molecules adsorbed . The equation used is Equation A2-21. 

For adsorption from dilute liquid solutions in stagewise countercurrent operations, uiiere the Freundlich equation describes the adsorption equilibrium, derive aiudytical expressions in terms of R, iR, Iq, and Yff for the minimum adsorbent/solvent ratio when fresh adsorbent is used. 

The mathematical models that have been applied to the physical adsorption from liquid solutions are generally extensions of the theories that have been developed to describe the sorption of gases on solid surfaces with modifications to account for the competition between the solute and solvent for the adsorption sites. Two of these models have been applied to the adsorption isotherms of nonelectrolytes from solution they are the Langmuir model and the Brunauer, Emmett, and Teller (BET) model in addition the Freundlich empirical equation has also been used. In the Langmuir model it is assumed that the adsorbed species forms a monolayer on the surface of the adsorbent, that the adsorbed molecules... 

Adsorption at the solid-liquid interface is generally similar to the adsorption at the solid phase-gaseous phase interface. Theoretical modelling of the adsorption process is more difficult because, in addition to adsorbing dissolved substances, solvent is present (e.g. water), the molecules of which can also adsorb, and interactions of adsorbed molecules with molecules of the solvent may occur. Molecular adsorptions, when molecules of a substance are adsorbed, and ion adsorptions, in which ions of a substance are adsorbed, can similarly take place. Solid phase-liquid phase interfaces are usually described by empirical equations and theoretically derived equations of the Freundlich and Langmuir type. 

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