it is about membrane fouling

1. Presented to:Dr.Haq nawaz bhatti&Dr.Sadia
Presented by:AnnaAjaz
Reg No.:2015-ag-238
Supervisor:Dr Ijaz Ahmed bhatti
Fouling of Photo catalytic
membrane reactors
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2. Introduction
Role Of Membrane In PMRs
Variants Of Membranes
Photocatalytic Membrane Fouling
Foulant Types
Classification Of Membrane Fouling
Forms Of Membrane Fouling
Mechanism Of Photocatalytic Membrane Fouling
Categories Of Photocatalytic Membrane Fouling
 Mambrane Fouling Consequences
Effect Of Photaocatalytic Process On Membrane Fouling
Prevention & Control for Membrane fouling
Conclusion 2

3. Introduction
A photocatalytic membrane reactor is a device which combine a
photocatalyst and a membrane to produce chemical transformation
PMRs are of two types
 Slurry PMR
Immobilized PMR (a)
Fig:a) Slurry PMR (b) Immobilized PMR
fig
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4. Fouling is the coverage of the membrane
surface (external and internal) by deposits
which adsorb or simply accumulate during
operation.
Fig: membrane fouling
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5. PHOTOCATALYSIS
Photocatalysis is defined as initiation of chemical reaction under
the action of ultraviolet, visible, or infrared radiation in the
presence of a substance the photocatalyst that absorbs light and
is involved in the chemical transformation of the reaction
pollutants”.
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6. PHOTOCATALYST
A photocatalyst is a “substance able to produce,
by absorption of ultraviolet, visible, or infrared
radiation, chemical transformations of the
reaction pollutants.
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7. 7Photocatalytic process

8. ROLE OF MEMBRANES IN PMRS
In a PMR the membrane can assume many roles, such as :
Separation.
 Retention of the catalyst.
Catalyst support.
Recovery of catalyst.
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9. VARIANTS OF MEMBRANES
Two ways in which membrane is used in PMR
 Catalysts are suspending in the reaction solution and the membrane is only used
to serve as an effective barrier
• Immobilization of catalyst on membrane surface .
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10. PHOTOCATLYTIC MEMBRANE FOULING
• Photo catalytic reactions of organic pollutants and photocatalysts
interaction with membrane surface
 Without ultraviolet (UV) irradiation, adsorption occurs.
 Under UV irradiation pollutant degradation takes place .
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11. FOULANT TYPES
 Substances that deposit on the membrane surface and cause its fouling are
called foulants.
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12. CLASSIFICATION OF MEMBRANEFOULING
Membrane fouling may be classified as
 External fouling
 Internal fouling
 Fig: External and Internal fouling
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13. FORMS OF FOULING
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FOULING
FORMS
ADSORPTION
DEPOSITION
GEL/CAKE
FORMATION

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15. MECHANISM OF PHOTOCATALYTIC
MEMBRANE FOULING
In PMRs, fouling mechanisms can be mainly divided into two
stages:
(a)Pore blocking
(b)Cake layer
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Schematic illustration of membrane fouling mechanisms: (a) pore blocking and (b) cake layer.

16. FOULING CATEGORIES
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Irreversible
fouling
Reversible
fouling

17. MEMBRANE FOULING CONSEQUENCES
• Blocking of membrane pores,
 Permeate flux decreases
 Production efficiency decreases
 Operation time increases.
 Dense cake layer of catalyst forms
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18. EFFECT OF PHOTOCATALYTIC PROCESS
ON MEMBRANE FOULING
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CATALYST PARTICLES REACTOR DESIGN
LIGHT INTENSITY
LOADING OF
PHOTOCATALYST
pH
INORGANIC IONS

19. MEMBRANE FOULING PREVENTION
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PRE-TREATMENT OF FEED SOLUTION
MEMBRANE MODIFICATION
PHYSICAL CLEANING
CHEMICAL CLEANING
SELF-CLEANING PROCESS
Optimization of operating parameters

20. CONCLUSION
 The major problem in photocatalytic membrane reactors is the fouling of
membrane .
 Membrane fouling is caused by deposited substances on the membrane surface
and are called foulants.
 Fouling can be organic,inorganic,collidal or biological.
 Fouling can be occurred due to adsorption, pore blockage or due to cake
formation
 Reduced by physical and chemical methods or by modification of membrane
or by pre-treating the feed solution.
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21. REFRENCES
 Mozia, S. (2015). "On photocatalytic membrane reactors in water and wastewater
treatment and organic synthesis." Copernican Letters 6: 17-23.
 Pearce, G. (2007). "Introduction to membranes: Fouling control." Filtration &
separation 44(6): 30-32
 Shi, X., G. Tal, et al. (2014). "Fouling and cleaning of ultrafiltration membranes: a
review." Journal of Water Process Engineering 1: 121-138.
 Trägårdh, G. (1989). "Membrane cleaning." Desalination 71(3): 325-335.
 Zhang, G., L. Yao, et al. (2012). "Photocatalytic membrane reactor used for water and
wastewater treatment." Recent Patents on Engineering 6(2): 127-136.
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