The Langmuir plot (Ce/qe vs. Ce) for RR2 adsorption at room temperatures gives a straight line and the value of Qm and KL constants and the correlation coefficients for this model are presented in Table 5 and Figure 6. The isotherm of RR2 on AC was found to be linear over the whole concentration range studies with extremely high correlation coefficients (R2:0.91). The essential features of the Langmuir isotherm may be expressed in terms of the equilibrium parameter RL, which is a dimensionless constant referred to as the separation factor or equilibrium parameter (Equation (6)):
(6)
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Table 5
Isotherm model parameters and correlation coefficients for RR2 adsorption on AC
| Isotherm | Langmuir | Freundlich | Temkin | |||||
|---|---|---|---|---|---|---|---|---|
| Parameter | R2 | qm | K1 | R2 | Kf | 1/n | R2 | B |
| Value | 0.91 | 33 | 0.0007 | 0.96 | 8.51 | 0.66 | 0.99 | 0.37 |
| Isotherm | Langmuir | Freundlich | Temkin | |||||
|---|---|---|---|---|---|---|---|---|
| Parameter | R2 | qm | K1 | R2 | Kf | 1/n | R2 | B |
| Value | 0.91 | 33 | 0.0007 | 0.96 | 8.51 | 0.66 | 0.99 | 0.37 |
Figure 6
Isotherm plots (a) Langmuir, (b) Freundlich, and (c) Temkin for RR2 adsorption onto prepared adsorbent (pH 7, adsorbent dosage of 6.25 g L−1 at 25 °C).
Figure 6
Isotherm plots (a) Langmuir, (b) Freundlich, and (c) Temkin for RR2 adsorption onto prepared adsorbent (pH 7, adsorbent dosage of 6.25 g L−1 at 25 °C).