C. Analysis of Adsorption Isotherm
The equilibrium study is important for an adsorption process
as it shows the capacity of the adsorbent and the adsorption
isotherm is normally applied to describe the adsorption
mechanism for the interaction of cations on the adsorbent
surface. In the present study, experimental data were analyzed
to examine the adsorption isotherm using Langmuir and
Freundlich models. The Langmuir isotherm is applicable to
monolayer adsorbate coverage on the adsorbent surface [9],
whereas the Freundlich isotherm is an empirical model that
considers heterogeneous adsorption on the adsorbent surface
[10]. The linearized equations for the Langmuir and Freundlich
isotherms are expressed as (4) and (5), respectively: