Photoadsorption Freundlich

Figure 6 Experimental values of phenol concentration vs. irradiation time. Ti02 P25 catalyst amount 0.32 g L , lamp power, 500 W. The empty symbols indicate the concentration of starting solution. The solid lines represent the Freundlich photoadsorption model [Equation (26)].

Figure 11 Linear form of Freundlich model. The left-hand side of Equation (19), n /W, vs. Cl,o° for runs carried out under irradiation with lamp power of 500 W. The solid line represents the Freundlich photoadsorption model [Equation (20)].

The suitability of Freundlich model to describe the photoadsorption phenomenon has been further checked by using the Freundlich equation [Equation (20)] in its linear form. Figure 11 reports the values of the fts/W group obtained from runs carried out at equal mass of catalyst vs. the square... 

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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