Linear plot of Langmuir isotherm model is obtained by the formula
Ce/Qe =Ce/Qm + 1/(Qm*KL)
Qm can be calculated from the slope of the plot. KL can be obtained from the intercept. KL is Langmuir constant. It has any relation with the rate of adsorption or energy of adsorption if both the adsorbent and adsorbate are solids?
How it can be explained?
It is the equlibrium constant - the ratio of the adsorption to the desorption rates at that temeprature
Hi there,
There is also another point that can be concluded from kl value.
Kl value can be a criteria of the affinity between your absorbent and adsorbate molecules. higher magnitude of Kl, more affinity between the absorbent and adsorbate molecules.
how to calculate Kl value if the intercept of linear plot is zero.
Is Kl can be infinite
The Langmuir constant (K) indicates the extent of interaction between adsorbate and the surface. If the value of K is relatively larger it indicates that there is a strong interaction between adsorbate and adsorbent while smaller value implies a weak interaction.
The values of the Langmuir KL constant, is related to the affinity of the ions to the adsorption sites, the high values of KL imply a greater affinity of the ions studied towards to the adsorbent.
https://www.researchgate.net/post/What_is_the_physical_significance_of_the_constant_K_in_langmuir_adsorption_isotherm2
The Langmuir KL constant is a measure of the metal ions affinity to the adsorption sites. Can be approximated with a the equilibrium constant.
For Langmuir Isotherm model, the simple linear equation is
Ce/Qe =Ce/Qm + 1/(Qm*KL)
Where Ce represents the equilibrium concentration (mg/g), qe is the quantity adsorbed at equilibrium (mg/g), Qmax and KL are constants which represent the adsorption capacity and energy of adsorption respectively. The constants are obtained from the plots of Ce/qe against the Ce.
KL can be used to determine the value of RL = 1/1+CoKL
Where Co is the initial concentration of the adsorbate. When the RL value is less than unity, the adsorption is said to be favorable and when greater than unity is considered as unfavorable. Also, when RL is equals to 0, the adsorption is irreversible, and the unity value represent the linearity of the adsorption.
KL is Langmuir constant related to the sorption energy, it is the affinity of adsorbent toward the adsorbat. High values of KL implies strong binding.
Equilibrium constant = Qm*KL
The constant K in Langmuir isotherm one may try to identify with the equilibrium constant. In the case of adsorption in the liquid-solid system, however, we should not treat this constant as a physical parameter. But, it can be used to compute the value of qm. In fact, the Langmuir equation was derived for the gas-solid system.
Can the KL value increase and then decrease in case of adsorption or it should have a trend with respect to the increase in temperature, please suggest
This video indoduces how to compare experimental and calculated maximum adsorption capacity, qmax value in adsorption isotherm study easily! #aminulcheminnovation #AminulSir
https://youtu.be/GYCUOcpiUec
https://www.researchgate.net/post/How_to_interpret_the_sign_and_the_amount_of_the_thermodynamic_parameters_for_metal_ion_removals
An attempt to interpret KL value, especially for the liquid-solid system, may be deceptive, but one should also remember about the drawbacks of graphical methods when we have data, e.g. only for large Co values or only for small Co values.