What does the Langmuir isotherm show?
The Langmuir isotherm describes the maximum amount of gas that a shale can hold at a specified pressure and temperature. Several factors may result in a shale holding less than the maximum amount of gas as represented by the isotherm. Such shales are termed undersaturated.
How do you calculate Langmuir?
How can I plot the Langmuir adsorption isotherm? ce/qe = 1/qm KL + ce/qm , where ce is the equilibrium concentration of the adsorbate and qe is the adsorption capacity adsorbed at equilibrium, qm is maximum adsorption capacity and KL is the Langmuir adsorption constant.
What is competitive adsorption?
Competitive adsorption is the usual situation in real applications, and it is of critical importance in determining the overall performance of an adsorbent. The adsorption of aqueous metal ion species, M2+(aq), on acidic oxygen functional group sites mainly involves an ion exchange mechanism.
Why is the Langmuir isotherm important?
For example qm from Langmuir isotherm is very important when you design your batch system for wastewater treatment. Rl from the same isotherm give an indication about the favorability of the adsorption system. From D-R model you can identify the type of adsorption; physical or chemical.
Why is adsorption exothermic in nature?
Adsorption is an exothermic process since surface particles of the adsorbent are unstable and when the adsorbate is adsorbed on the surface, the energy of adsorbent decreases, and this results in the evolution of heat. Therefore, adsorption is always exothermic.
How do you use Freundlich isotherm?
Freundlich isotherm in its logarithmic (A) and linear (B) forms….The Freundlich Isotherm.
| Adsorption isotherm | Equationa |
|---|---|
| Freundlich | Qe = kfCe(1/nf) also used as Qe = kfCen as used by oil processors x/m = KCn |
How is Freundlich isotherm derived?
The Freundlich adsorption isotherm is mostly presented as an empirical equation and the (fractal) Langmuir adsorption isotherm is derived from kinetics. However, their constants are determined by thermodynamic approach. It is irrelevant to use both adsorption isotherm separately.
What are the assumptions of Langmuir isotherm?
The Langmuir adsorption isotherm was derived by the US chemist Irving Langmuir (1881–1957), using the kinetic theory of gases and making the assumptions that: (1) the adsorption consists entirely of a monolayer at the surface; (2) there is no interaction between molecules on different sites and each site can hold only …