MATHEMATICAL SIMULATION OF BIOSEPARATION IN AN AFFINITY PACKED-COLUMN

Affinity chromatography (biospecific adsorption) relies on specific in teractions of biological molecules such as enzymes, antigens, antibodi es, and proteins. The process consists of three steps: adsorption, was hing, and elution. A mathematical model including convection, diffusio n, and reversible reaction is formulated to analyse the breakthrough b ehaviour of the solute. A moving finite element orthogonal collocation method is applied with respect to the space variables of the governin g partial differential equations of the model to evaluate the breakthr ough of the solute. Danckwerts' boundary conditions are considered for the column. The validity of the numerical scheme is checked by compar ison with an analytical solution for a simplified model. The results o btained from model simulation show that the breakthrough time of the s olute is significantly influenced by the axial dispersion coefficient, solute concentration, ligand content, reaction kinetics, particle por osity, particle size, and flow rate. Solute recovery and bed utilisati on efficiencies are evaluated for different values of the above parame ters.