Separation of yeast cells from aqueous solutions using magnetically stabilized fluidized beds.
OBJECTIVE
To separate Saccharomyces cerevisiae cells from aqueous solutions using magnetically stabilized fluidized beds (MSFB) that utilize a horizontal magnetic field, and to study the effect of some parameters, such as bed porosity and height, liquid flow rate and inlet concentration on cell removal efficiency and breakthrough curves.


RESULTS
The separation process was conducted in an MSFB under the effect of horizontal magnetic field. The magnetic particles used consist of a ferromagnetic core of magnetite (Fe3O4) covered by a stable layer of activated carbon to adsorb the yeast cells from the suspension. The yeast cell concentration in the effluent was determined periodically by measuring the absorbance at 610 nm. The effect of the magnetic field intensity on the bed porosity and consequently the exit-normalized cell concentration from the bed was studied. It was found that bed porosity increased by 75%, and the normalized cell concentration in the bed effluent decreased by 30%, when the magnetic field intensity was increased from 0 to 110 mT. In addition, increasing the magnetic field intensity and bed height delayed the breakthrough point, and allowed efficient cell removal. These results demonstrate an improved method to separate cells of low concentration from cell suspension.


CONCLUSIONS
This study allows the continuous separation of yeast cells from aqueous solutions in an MSFB. The removal efficiency is affected by different parameters including the bed height, flow rate and initial concentration. The removal efficiency reaches 82%, and could be improved by varying the operational parameters.


CONCLUSIONS
The results obtained in this investigation show that the MSFB using horizontal fields represents a potential tool for the continuous separation of cell suspension from aqueous solution. This study will contribute to a better understanding of the hydrodynamic parameters on the separation efficiencies of the cell.
Al-Qodah
Z
Z
Department of Chemical Engineering, Al-Balqa Applied University, Amman, Jordan. z_Alqodah@hotmail.com
Al-Shannag
M
M
D002469:Cell Separation / Q000295:instrumentation* / Q000379:methods*; D008280:Magnetics; D012441:Saccharomyces cerevisiae / Q000302:isolation & purification*; D012996:Solutions; D014867:Water
D012996:Solutions; D014867:Water