The basic phenomena in solid-liquid adsorption systems involves the movement of macromolecules from a liquid solution to the active sites located in the interior of the pores of the adsorbent. Therefore, the phenomenon is controlled by mass transfer mechanisms. These mechanisms consist of external diffusion, the effective diffusion in the pores and the velocity of the adsorption on the active site of the adsorbent. In this work, the mass transfer coefficients and the coefficients of the adsorption isotherm are estimated using an implicit formulation with the cost function of the squared residues, between calculated and measured concentrations, being minimized with the Levenberg-Marquardt method. One configuration was considered: the transient experimental data on the solute concentration is obtained in a stirred-bath system. In the implicit formulation considered here, the direct problem is solved several times along the iterative procedure used for the solution of the inverse problem. The solutions of the direct problems were obtained using a combination of finite volume method and finite difference method, and were validated with real experimental data of the concentration for the protein Bovine Serum Albumin (BSA) on Accell Plus QMA(R) macro porous adsorbent resin using Tris-HCL buffer solution.115391408