Research Article

Finite Volume Scheme for Double Convection-Diffusion Exchange of Solutes in Bicarbonate High-Flux Hollow-Fiber Dialyzer Therapy

Figure 9

Bicarbonate concentration profiles at various time periods and radial distances in the membrane were presented. At different time periods, bicarbonate concentration increased rapidly for during the first 30 minutes and then slowly for another 10 minutes, before becoming stable for the rest of the therapy (a). The maximum concentration reached was within the physiologic range reported by clinical studies. In (b), the bicarbonate concentration profiles within the first 40 minutes at various radial distances were found to increase until the membrane becoming nearly saturated with the solute. However, concentration at the fiber walls was much higher than that in the fiber center.
973424.fig.009a
(a) Concentrations at various time periods
973424.fig.009b
(b) Concentration for various radial positions