Cross-flow membrane microfiltration of a bacteriol fermentation broth

Area of Science:

• Biochemical Engineering
• Separation Science
• Biotechnology

Background:

• Cross-flow membrane filtration is valuable for cell harvesting and enzyme recovery.
• Membrane fouling by solute deposition (cake formation) hinders performance and retention.
• Understanding fouling is crucial for optimizing filtration processes.

Purpose of the Study:

• Investigate factors causing performance decline in B. polymyxa broth microfiltration.
• Identify the primary foulant responsible for membrane fouling.
• Test a new solids flux model for mass transport.

Main Methods:

• Varied system parameters: axial flow rate, feed concentration (cells, proteins), membrane materials (ceramic, polypropylene, stainless steel), and cleaning methods.
• Employed diagnostic methods to identify foulants.
• Applied a new solids flux mass transport model.

Main Results:

• Magnesium ammonium phosphate precipitate, formed during steam sterilization, was identified as the major foulant.
• Cake formation increased resistance to flow and affected retention.
• The solids flux model was tested to explain fouling phenomena.

Conclusions:

• Magnesium ammonium phosphate precipitate is the primary cause of performance loss in B. polymyxa broth microfiltration.
• System parameters and membrane material influence fouling.
• Further research can refine fouling models and mitigation strategies.