MIHAELA NEAGU, DANIELA ROXANA POPOVICI, CRISTINA MARIA DUSESCU, CATALINA CALIN ADSORPTION OF P-CRESOL BY MESOPOROUS ACTIVATED CARBON. I. KINETICS STUDIES AND DATA MODELING The kinetic adsorption of p-cresol from aqueous solution onto mesoporous activated carbon was investigated for 100, 500 and 1000 mg L-1 initial concentrations, at constant 295 K temperature. The kinetic of the adsorption process was discussed using three kinetic models, i.e., pseudo-first order kinetic model, pseudo-second order kinetic model, and Avrami fractionary order kinetic model. In order to provide a mathematically rigorous method for evaluating the kinetic parameters using the original form of the kinetic models, the nonlinear regression was selected as most viable algorithm. The common statistical tools was employed to check the accuracy of fit measure, namely, sum of the squares of the errors SSE, reduced sum of the squares of the errors Red-SSE, coefficient of determination R2, adjusted coefficient of determination Adj R2 and standard deviation SD.