Our specific objectives were to generate P sorption isotherms
and Langmuir parameters Qmax and k of A and B horizon soils from locations across the tropical climate zone, and to determine whether any soil characteristics significantly contributed to the variation of observed soil P sorption parameters.
In order to predict the behavior of adsorption isotherms
, several authors have proposed empirical and theoretical mathematical models to fit the equilibrium moisture curves of various products as a function of the water activity (Bezerra, Costa, Afonso, Maia, & Clemente, 2011).
The Langmuir isotherm
model gave better fit for the adsorption process.
Sorption on the soils is given through isotherms
as shown in figure 1 and figure 2.
In order to achieve that, first, the sodium [R.sub.d] is experimentally determined using undisturbed sandy columns and then the [R.sub.d] were determined based on the methods proposed by Freeze and Cherry (1979), by van Genuchten and Parker (1984), by the fit of the sorption isotherms
models to the experimental data obtained from column experiments, and by fitting the analytical solution of the ADE to the experimental data.
Adsorption Freundlich and Langmuir isotherms
were employed to describe the adsorption of Zn and Cu on Oxisol (Munchong Series) and Ultisol (Bungor Series) amended with sewage sludge.
Given this assumption, this study aimed to determine desorption isotherms
and isosteric heat of yellow mombin (Spondias mombin L.), for different conditions of temperature and water activity.
The application of linear and nonlinear forms of equilibrium isotherms
was to determine appropriate isotherm
for the purpose, and thermodynamic and kinetic studies were performed to check reaction nature of the adsorption phenomenon.
Characteristics of the Moisture Sorption Isotherms
. The experimental moisture sorption isotherm
data for millet flour (MF) were obtained at 25, 40, and 55[degrees]C and water activity range from 0.1 to 0.9 (Figure 1) which exhibited sigmoidal shape (type II isotherm
Temkin and Dibinin-Radushkevich Isotherms
Studies of equilibrium sorption of [Zn.sup.2+] unto phosphoric acid modified rise husk, Journal of Applied Chemistry, 3: 38-45.
Contaminant sorption process of different solutes in the soils is generally described using isotherms
. Sorption isotherms
describe the concentration of the sorbed solute to the sorbent concentration at equilibrium.