Langmuir Isotherb Speech

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The adsorption surfaces have the same affinity for molecules of the adsorbate and there is no trans-migration of adsorbate on the plane of the surface. The Freundlich equation is mostly used for data description whereas Langmuir isotherm is valid for single-layer adsorption. Adsorption is the process considered to be efficient to defluoridate the water. To defluoridize, there are many techniques but when compared to the physical and chemical methods of defluoridization, the physical method is the most suitable and economic. In physical method, various adsorbents are used to remove fluoride from water. Different adsorbents are derived from different materials and objects. Till now there is no method to defluoridize water which is…show more content…
The above equation can be represented in a linear form as log⁡〖q_e=log⁡K+ 1/n*log⁡C 〗
The coefficients k and n can be estimated from slopes and by substituting values from a line fitted to a graph of log (X/M) versus log C.
Langmuir Isotherm
The simplest proposed model for characterizing adsorption is the Langmuir isotherm (20). The Langmuir isotherm assumes that each unit of surface area consists of n sites, which can adsorb one molecule, and all of the sites are energetically equivalent. Surface contains uniform energies of adsorption. Maximum adsorption corresponds to a saturated monolayer of solute molecules on the adsorbent surface, that the energy of adsorption is constant, and that there is no transmigration of adsorbate in the plane of the surface. This model is an adequate approximation for uniform surfaces. However, it is inaccurate for inorganic solids commonly used in catalytic materials. In addition, the model does not account for the interaction of adsorbed species and multi layer adsorbate growth. The Langmuir isotherm is developed by assuming that a fixed number of adsorption sites are available, and that the adsorption is reversible. The Langmuir isotherm may be used when the adsorbent surface is homogeneous. The Langmuir isotherm is expressed as
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qmax = amount adsorbed to form a complete monolayer on the surface. (mg)
The above equation can be recast in a linear form as
Ce/(X/M)=Ce/q_max +1/(q_max b) And the equilibrium parameter (RL) can be calculated from the following equation, RL = 1/(1+bCo)
Which represent the monolayer adsorption of the adsorbent If, RL = 0, adsorption is irreversible RL = 1, adsorption is linear 0 < RL < 1, adsorption is favourable RL > 1, adsorption is unfavourable

Batch Flow Mode of Operation
In batch type contact operation, a quantity of adsorbents is mixed continuously with specific volume of wastewater, until the pollutant in that solution has been decreased to a desired level. The adsorbent is then removed and either discarded or regenerated for use with another volume of solution. Batch type process is usually limited to the treatment of small volume of

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