Bilirubin removal from albumin-containing solutions: dynamic adsorption on anionic resin

In this paper, kinetics of unconjugated bilirubin adsorption in fixed-bed anionic resin columns was investigated. Experimental breakthrough curves were determined at different feed flow rates and using inlet solutions with different bilirubin and albumin concentrations. A mathematical model is provided to describe the effect of albumin on bilirubin adsorption equilibrium and kinetics in a fixed-bed column. Breakthrough curves show that a significant bilirubin concentration is present in the column outlet stream even in the early operating time. This result shows that, with the flowrates used in this work, adsorption is slow with respect to the axial convection in the column and, as a consequence, bilirubin is never completely removed from the liquid phase. The results obtained in this paper may be useful for the design of liver support devices such as Molecular Adsorbent Recirculating System (MARS), which implement anion-exchange columns to remove albumin-bound toxins from concentrated albumin solutions. (C) 2009 Curtin University of Technology and John Wiley & Sons, Ltd.