Filtration TutorialFiltration TutorialThis tutorial is designed to enhance knowledge of the This tutorial is designed to enhance knowledge of the

purification processes used in biotechnology. The topics purification processes used in biotechnology. The topics covered in this tutorial are meant to provide a succinct covered in this tutorial are meant to provide a succinct

overview of microfiltration and ultrafiltration processes. A overview of microfiltration and ultrafiltration processes. A more inmore in--depth study will be referenced throughout the depth study will be referenced throughout the tutorial. It is recommended that an examination of the tutorial. It is recommended that an examination of the references be performed to further explain any of the references be performed to further explain any of the

concepts covered in this brief tutorial.concepts covered in this brief tutorial.

OverviewOverview

Types of FiltrationTypes of FiltrationMicrofiltrationMicrofiltration

How it works?How it works?UltrafiltrationUltrafiltration

How it works?How it works?Microfiltration vs. UltrafiltrationMicrofiltration vs. UltrafiltrationReferencesReferences

Types of FiltrationTypes of Filtration2 Examples2 Examples::

1.1. Cross FlowCross Flow 2.2. Dead End FlowDead End Flow

Types of flow images from: http://www.che.utexas.edu/nams/IUPAC/iupac.html

Type 1: Cross FiltrationType 1: Cross FiltrationFlow parallel to Flow parallel to membrane surfacemembrane surface

Does Does notnot cause buildup, cause buildup, therefore does not suffer therefore does not suffer from reduced flow from reduced flow overtimeovertime

F = feed; F = feed; M = membrane; M = membrane; P = permeate; P = permeate; R = retentate R = retentate (components that do NOT (components that do NOT pass through the pass through the membrane)membrane)

Cross Flow diagram from: http://www.che.utexas.edu/nams/IUPAC/iupac.html

Type 2: Dead End FlowType 2: Dead End FlowFlow perpendicular to Flow perpendicular to membrane surface membrane surface

Causes build up of filter Causes build up of filter cake on membranecake on membrane

F = feed; F = feed; M = membrane; M = membrane; P =P = permeatepermeate(components that pass (components that pass through membrane)through membrane)

Dead-end Flow diagram from: http://www.che.utexas.edu/nams/IUPAC/iupac.html

MicrofiltrationMicrofiltration

Separates soluble contaminants remaining Separates soluble contaminants remaining within the within the supernatantsupernatant

SupernatantSupernatant may include:may include:Other proteinsOther proteinsBioBio--moleculesmoleculesUnUn--used growth mediaused growth media

Microfiltration image from: http://www.aaflow.de/filtertech/index.html

How does Microfiltration How does Microfiltration work?work?

Pressure driven processPressure driven process

Separates: Separates: Components in a solution Components in a solution or suspension or suspension based on based on molecular sizemolecular size

Particles size range:Particles size range:1010µµm (starches) to aprx. m (starches) to aprx. 0.040.04µµm (DNA, Viruses, m (DNA, Viruses, and globular proteins)and globular proteins)

Microfiltration image from: http://www.faireymicrofiltrex.com/Vokes%20Microfiltration/media/images/e-fluor.gif

UltrafiltrationUltrafiltrationUsually used to Usually used to furtherfurther separate any separate any contaminants able to contaminants able to pass through the pass through the microfiltration microfiltration membrane using a membrane using a pressure gradientpressure gradient

Ultrafiltration image from: http://www.awatec.ch/produkte/ultrafiltration.jpg

How does Ultrafiltration work?How does Ultrafiltration work?

Separates:Separates:Particle size range: Particle size range:

0.10.1µµm to 0.001m to 0.001µµm m

Usually based on Usually based on molecular weightmolecular weight

Typical range: Typical range: 200 to 300,000 g/mole200 to 300,000 g/mole

Ultrafiltration image from: http://www.toltecint.com/how_dialysis_works/how_hemodialysis_works.htm

Microfiltration vs. UltrafiltrationMicrofiltration vs. Ultrafiltration

Microfiltration:Microfiltration:Proteins act as the Proteins act as the permeatepermeate

UltrafiltrationUltrafiltrationProteins act as the Proteins act as the retentateretentate

Images from: http://www.geafiltration.com/html/technology/ftechnology.html

Microfiltration vs. UltrafiltrationMicrofiltration vs. UltrafiltrationMicrofiltration:Microfiltration:

Separates larger particles Separates larger particles For exampleFor example--

ColloidsColloidsFat globulesFat globulesCells Cells

Located upstream to Located upstream to reduce load and fouling reduce load and fouling capacity on ultrafiltration capacity on ultrafiltration membrane downstream membrane downstream

UltrafiltrationUltrafiltrationSeparates smaller particlesSeparates smaller particlesFor exampleFor example--

MacromoleculesMacromolecules

However, However, processes are processes are basically identicalbasically identical

ReferencesReferences[1] Case Study Solution [1] Case Study Solution -- Facility Design for Antigenic Facility Design for Antigenic CoCo--proteinsproteins (2003). CHE 451. NCSU(2003). CHE 451. NCSU[2] Grandison, A. S. & Lewis, M. J. (Eds.). (1996) [2] Grandison, A. S. & Lewis, M. J. (Eds.). (1996) Separation Processes in the Food and Biotechnology Separation Processes in the Food and Biotechnology IndustriesIndustries. Woodhead Publishing. Retrieved November . Woodhead Publishing. Retrieved November 30, 2003 from Knovel Chemistry and Chemical 30, 2003 from Knovel Chemistry and Chemical Engineering Database.Engineering Database.[3] Zeman, L. J. & Zydney, A. L. (1996) [3] Zeman, L. J. & Zydney, A. L. (1996) Microfiltration Microfiltration and Ultrafiltration: Principles and Applicationsand Ultrafiltration: Principles and Applications. New York: . New York: Marcel Dekker, Inc. Available via NCSU libraries as an Marcel Dekker, Inc. Available via NCSU libraries as an eBookeBook