Agarwal, "Removal of Orange-G and Methyl Violet dyes by adsorption onto bagasse fly ash--kinetic study and equilibrium isotherm
analyses," Dyes and pigments, vol.
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
A straight line for Langmuir plot shows that adsorption follows Langmuir's isotherm
and [q.sub.m] and [K.sub.L] can be determined from the slope and intercept of the plot respectively.
is extensively used to describe the sorption of solutes by soils .
Moreover, the essential characteristics of Langmuir isotherm
can be explained in terms of a dimensionless constant separation factor or equilibrium parameter [R.sub.L], which is defined by
equation has no Henry law (linear) behavior at low pressure and no saturation limit at high pressure.
A wide spectrum of Qmax and k values in P isotherm
studies have been reported for both temperate and tropical soils.
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 essential features, separation factor (RL) of the Langmuir isotherm
is expressed as:
Most of the data fitted the Freundlich isotherm
very well except, SS3 and SS5 as shown in figure 2.
Second, [R.sub.d] was determined using the method proposed by van Genuchten and Parker (1984) where the [R.sub.d] is the area above the BTC; Third, the [R.sub.d] determination was performed by using the method proposed by Freeze and Cherry (1979) where the [R.sub.d] is equal to the pore volume when the relative concentration (C/[C.sub.0]) is 0.5; and Fourth, the [R.sub.d] was found by fitting the sorption isotherms
, obtained through column test, to the linear, Freundlich and Langmuir isotherm
models (Freeze and Cherry, 1979; Garga and O'Shaughnessy, 1994; Fetter, 1999; Asgari et al., 2014).
The simplest isotherm
is the linear distribution coefficient (Kd), also called linear partition coefficient, is widely used to describe adsorption in soil .
Moisture sorption isotherm
characteristics of potato at four temperatures.
The experimental isotherm
of adsorption for Cr(VI) is shown in Fig.