However, since the Freundlich equation was found to describe more accurately the sorption phenomenon, the Clark model could be more appropriate for the approximation of the C. crinitophylla packed bed column system. The Clark model parameters can be seen in Table 3, Table 4 and Table 5. The model produces breakthrough values in good agreement-even though slightly underestimated-with the experimental values for all conditions tested, close to those ABT-199 produced by the Thomas model ( Table 3). R2 values are high, slightly higher than those of the Thomas model, indicating oviducts the Clark model is suitable for the prediction of the C. crinitophylla packed bed column system. r values, representing the mass transfer coefficient, show a significant increase with increasing flow rates ( Table 5), but do not show significant variations for either different feed concentrations or bed heights. Overall, the Clark model is also found suitable of approximating the experimental data and could be used effectively for the determination of the optimum working parameters when designing a C. crinitophylla packed bed column configuration.