Membrane Fouling Characterization by Confocal Scanning Laser Microscop
Unitat d'Enologia del CeRTA.
Departament d’Enginyeria Química, ETSEQ, URV
18.01.2005 Tarragona, Spain
student: Maria Zatorsupervisor: Carme Guell
3.from membrane separation to CSLM analysis...
2.Membrane fouling characterisation...
6.Future plans...
a. Importance...
Outlines
1.Membrane fouling ...
Membrane Fouling Characterization by Confocal Scanning Laser
Microscopy
b. Some definitions...
5.Conclusions...
4.Results...
1a. What is important ...
Fouling characterisation - generally
Fouling characterisation – present study
fundamental mechanisms& processes involved
not fully understood
novel, non-invasive, in-situ quantification of physico-chemical processes
key to breakthroughs in the understanding of fouling phenomena
Confocal Scanning Laser Microscope
appropriate strategy for membrane fouling characterization
1b. ...membrane fouling...
time, t
flu
x,
J
Flux as a function of time.
The biggest problem associated with the application of the separation processes for membranes is FOULING
What is the problem ...?
What is fouling ...?
The fouling is manifested as a decrease of the permeate flux during the time of
filtration
Why fouling is a problem ...?
The (ir)reversible deposition of retained particles, colloids, emulsions,
suspensions, macromolecules, salts etc. on or in the membrane.
INTERNAL FOULING
EXTERNAL FOULING
2. Membrane fouling characterisationIn situ methods
Monitoring techniques for concentration polarization
Visualization of the adsorption/deposition of particles on the surface of membranes
Monitoring techniques for pore blockage
Monitoring techniques for cake layer formation
Indirect methods
Analysis of the chemical composition of the permeate and
retentateEvaluation of permeate flux and
total resistance versus time
Chemical and physical analysis of membranes (microscopic
techniques: SEM and AFM)
New Method
CSLM
Confocal Scanning Laser Microscope
excellent technique to visualise protein adsorption to porous particles and membranes
3. From membrane separation to CSLM analysis
COMPUTER
5 %
BALANCE STIRRER PUMP
DEAD – ENDMODUL
1.
2.
4. moviol
3.
5.
coverglass
slide
CSLM
Sample preparationFiltration plant
Data gathering
4. Results
IMAGE ANALYSIS
Fouling morphology
Volumetric 3D reconstruction
CSLM : 6,5% +/- 0,5
SEM : 7,1 % +/- 0,6
Determination of surface porosity
Orthogonal view of the 3D
reconstruction
Location and identification
of the adsorbed/dep
osited proteins
CSLM BSA-fluorescein and OVA-TexasRed conjugate.
ZY
ZX
XY
OVA-TexasRed conjugate.
CSLM BSA-fluorescein and OVA-TexasRed
conjugate.
BSA-fluorescein conjugate.
Data about pore surface
in which protein was
detected
5. Conclusions
CSLM can be used to characterize membraneCSLM can be used to characterize membrane
several agents in a mixture that cause fouling can be visualised
several agents in a mixture that cause fouling can be visualised
information about the presence of proteins on the surface
and inside the membrane can be obtained
information about the presence of proteins on the surface
and inside the membrane can be obtained
prevailing mechanism during fouling and the major fouling agent can be identified
prevailing mechanism during fouling and the major fouling agent can be identified
the formation of cake on the top of the membrane and/or the pore constriction caused by
deposition or adsorption of foulant can be visualised
the formation of cake on the top of the membrane and/or the pore constriction caused by
deposition or adsorption of foulant can be visualisedZY
ZX
XY
6. ... and further steps...
FUTURE PLANS
Quantitative information about membrane
fouling
Characterisation of reversible/irreversible
membrane fouling
filtration module modifications to carry out
on-line experiments
Set up membranecleaning procedure
Questions ?????
