4.2 Adsorption isotherm
As stated before, the experimental adsorption isotherms represent the balance between adsorbent and adsorbate at equilibrium conditions. Figure 3 shows the adsorption isotherm for trans -cyclooctene on AgNO3/silica at 23˚C. Provided that the adsorption isotherm obeys the Langmuir isotherm type, \(\frac{C_{B_{e}}}{q_{B}}\)versus \(C_{B_{e}}\)should represent a linear behavior. Furthermore,\(\frac{C_{B_{e}}}{q_{B}}\) versus \(C_{B_{e}}\) has been plotted, from which it can be observed that \(\frac{C_{B_{e}}}{q_{B}}\) is a linear function of \(C_{B_{e}}\). The results indicate that the adsorption of TCO on AgNO3 obeys the Langmuir isotherm model and the highest adsorption capacity was recorded at 43.089 mg/g at initial concentration of 5.85 g/dm3.
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Figure 3. Adsorption isotherm of trans-cyclooctene on the AgNO3/SiO2 at 23˚C, WAgNO3=0.175 g,\(\frac{\mathbf{C}_{\mathbf{\text{Be}}}}{\mathbf{q}_{\mathbf{\text{Be}}}}\mathbf{=17.515}\mathbf{C}_{\mathbf{B}_{\mathbf{e}}}\mathbf{+20.529,\ }\mathbf{R}^{\mathbf{2}}\mathbf{=0.965}\); (a) nonlinearized form and (b) linearized form (Eq. 3.3 ), for calculated parameters b and qBmax, see Table 1
Accordingly, the Langmuir model parameters, \(b\) and \(q_{B_{\max}}\), have been calculated see Table 1.
Table 1 Langmuir isotherm parameter b and qBmaxfor TCO adsorption on AgNO3/silica at 296.15 K