Photoadsorption Langmuir

Figure 3 Experimental values of benzyl alcohol concentration vs. irradiation time. Home-prepared catalyst amount 0.4 g L lamp power, 125 W. The empty symbols indicate the concentration of starting solution. The solid lines represent the Langmuir photoadsorption model [Equation (19)] (Yurdakal et at, 2008b).

Figure 8 Linearform of Langmuir model. The left-hand side of Equation (A18), Cl,o/(Ct,o - C o), vs. Cl 0 for runs carried out under irradiation with lamp power of 125 W ( ), 500 W (a), and in the dark (o). The dark data are multiplied for 0 The solid lines represent the Langmuir photoadsorption model [Equation (A18)] (Yurdakal et al., 2008b).

Langmuir photoadsorption equilibrium constant (M ) Redlich-Peterson isotherm constant (dm g )... 

The suitability of Langmuir model fo describe the photoadsorption phenomenon has been further checked by using the linear form of Langmuir equation [Equation (A18)]. Figure 8 reports the values of the Cl,o/(Ct,o Cl,o)... 

The values of kinetic and Freundlich parameters (k, Kp, and Ng), obtained from runs carried out with different amounts of catalyst, are reported in Figure 12 vs. the absorbed photon flow per unit mass of catalyst. These values show the same feature of Langmuir parameters obtained for benzyl alcohol oxidation, that is, they decrease by decreasing the photon flow absorbed by the unit mass of catalyst. As in the case of benzyl alcohol, the consideration that the photon flow absorbed by the unit mass of catalyst is the parameter mainly affecting the photoadsorption phenomenon is strengthened by the results reported in Figure 12. 

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