Mass transfer limitations in protein separations using ion-exchange membranes

Area of Science:

• Biomaterials science
• Chemical engineering
• Separation science

Background:

• Bovine serum albumin (BSA) sorption to membranes impacts filtration efficiency.
• Commercial membranes with 150-micron pore size were used.
• Flow-rate dependence of sorption was observed, not explained by system dispersion.

Purpose of the Study:

• To investigate the sorption kinetics of BSA onto membranes.
• To identify the rate-limiting factors in BSA sorption.
• To determine the maximum pore size to eliminate mass transfer limitations.

Main Methods:

• Batch and flow experiments were conducted to measure BSA sorption.
• Langmuir sorption, convection, and diffusion models were applied to analyze breakthrough and elution curves.
• System dispersion was accounted for but could not explain observed flow-rate dependence.

Main Results:

• Early and broad breakthrough curves and asymmetric elution peaks were observed.
• Sorption kinetics were strongly dependent on flow-rate.
• Film mass transfer resistance was identified as the rate-limiting factor.

Conclusions:

• Film mass transfer resistance significantly affects BSA sorption to membranes.
• The study provides a method to calculate the maximum allowable pore size to mitigate this limitation.
• Findings are crucial for designing efficient membrane-based separation processes for various solutes.