Electrosorption of phenol

Fig. I3J Schematic representation of the potential dependence of the electrosorption of phenol and of the phenoxy radical on Pt, at three concentrations in solution.

Fig. IJ The electrosorption of phenol from (a) aqueous and (b) methano-lic solutions, as a function of the charge density on a mercury electrode. Supporting electrolyte-. 0.] M LiCl, the concentrations of phenol are marked on the curves. From Muller, Ph.D dissertation, Univ. of Pennsylvania, 1965.

In the case of electrosorption, it is best to use a dimensionless scale of C/C(sat) when comparing the adsorjTtion of different solute molecules in the same solvent, or the same solute in different solvents. This scale permits us to compensate for the differences in the free energy of interaction between the solvent and the solute, and the effects seen arise from the different interactions of the solutes with the surface. A good example is the adsorption of phenol on mercury from two different solvents, shown in Fig. IJ. The solubility of phenol in water is much lower than in methanol. It takes therefore a much higher concentration in methanol to reach a given value of the fractional coverage 0 than in an aqueous solution. 

This chapter describes water purification processes where an electrode process is combined with a membrane process. Special emphasis is placed on processes where the membrane acts as an electrode. Porous electrodes or electrodes that could potentially be used as membranes are also included in this chapter. The last two sections describe two case studies of electrosorption of ions from wastewater and anodic decomposition of phenol, respectively. 

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