Data shown in Table 4 corroborate the conclusions already drawn from Figure 9: after a number of passages between 25 and 38, a quasi equilibrium condition was attained with little influence of the initial phenol concentration. In all instances, the model under predicted equilibrium concentrations. At the high initial phenol concentration levels, where uncertainties in chemical analysis are small, model predictions were considered very satisfactory (deviations in the range of 3.4 – 5.4 %). For mid and low concentrations, model predictions were considered just reasonable (deviations in the range of 8.7 – 16.6 %). However, it is important to remember that the model is very simple and reliable: it is based on a straight forward material balance of phenol and on the accuracy of the Freundlich isotherm in representing adsorption equilibrium. Errors, human and instrumental, are introduced mainly via measurements.