Article

Optimization of ultrafiltration/diafiltration processes for partially bound impurities.

Department of Chemical Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, USA.
Biotechnology and Bioengineering (Impact Factor: 4.16). 09/2004; 87(3):286-92. DOI: 10.1002/bit.20113
Source: PubMed

ABSTRACT Ultrafiltration and diafiltration processes are used extensively for removal of a variety of small impurities from biological products. There has, however, been no experimental or theoretical analysis of the effects of impurity- product binding on the rate of impurity removal during these processes. Model calculations were performed to account for the effects of equilibrium binding between a small impurity and a large (retained) product on impurity clearance. Experiments were performed using D-tryptophan and bovine serum albumin as a model system. The results clearly demonstrate that binding interactions can dramatically reduce the rate of small impurity removal, leading to large increases in the required number of diavolumes. The optimal product concentration for performing the diafiltration shifts to lower product concentrations in the presence of strong binding interactions. Approximate analytical expressions for the impurity removal were developed which can provide a guide for the design and optimization of industrial ultrafiltration/diafiltration processes.

0 Bookmarks
 · 
132 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: In this article, the self-sharpening phenomenon arisen by ion-exchange membranes is studied. In order to reduce the overlapped components in a single chamber, aminated poly(2,6-dimethyl-1,4-phenylene oxide) (APPO) based anion-exchange membranes are applied in free-flow isoelectric focusing (FFIEF) instead of conventional immobiline membranes as the selective mass transfer media. The APPO polymers with different amination rates are blended with polysulfone and cast on non-woven clothes by the phase inversion technology. Characterizations of XPS scanning, streaming potential and ion-exchange capacity (IEC) demonstrate that the self-prepared membranes posses different extent of amination and IEC values. The performances of the three prepared APPO membranes with different IEC values are compared. Nine pieces identical solid phase porous APPO membranes are employed in FFIEF instead of pH imbedded gel-like immobiline membrane with a protein mixture comprising bovine serum albumin, myoglobin and lysozyme as a separation model. Experimental results show that membranes with the higher charge density perform not only the higher mass transfer rate, but also the stronger “self-sharpening” function. Therefore, the highly charged porous membranes are favorable in reducing components’ overlaps in individual chamber for multi-component protein separations.
    Chemical Engineering Science 12/2009; · 2.61 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Graphical abstract Figure optionsView in workspace Highlights ► Dimensionless variables are introduced to obtain normalized model equations. ► Theoretical analysis provides properties of optimal solution of control problem. ► Numerical methods of dynamic optimization prove optimal operating policy. ► Optimization diagrams allow easy determination of the diluant utilization strategy.
    Journal of Membrane Science 09/2011; 380(1-2):148-154. · 4.91 Impact Factor
  • Desalination 08/2014; 346:100–106. · 3.96 Impact Factor

Full-text

Download
3 Downloads