This presentation explains about membrane filtration and its type. I collected information from different source and accumulated to make this. Hope you will find it useful.

1. Filtration
Filtration is an operation by which solid particles are separated
from a liquid or gas, by forcing the mixture through a
porous medium that retains the particles.

2. Purpose of filtration
• To remove undesirable solid particles from a liquid product
• To recovery of a solid product from a solid/liquid mixture

3. Membrane Filtration
It is an integral part of many industrial processes, as it often more
environmentally sustainable and cost effective than other filtration or
separation technologies.

4. Lets know about Membrane
So a membrane most commonly is a thin film of material with
selective permeability.
Membrane-based separation processes make use of this selective
permeability.

5. What are they made of
The membrane itself is crucial to the process.
The first commercial membranes were made of cellulose acetate
Temperatures had to be maintained below 30C and the pH range was 3–6.
These constraints limited their use, as they could not be disinfected by heat
or cleaned with acid or alkali detergents.

6. What then happened?
Then during mid-1970s polymeric membranes with polyamides were
made but it still was low tolerant to chlorine.
It is estimated that over 150 organic polymers have now been investigated
for membrane applications.
Inorganic membranes based on sintered and ceramic materials are also
now available and these are much more resistant to heat and cleaning and
disinfecting fluids.

7. Types of Membrane filtration
A considerable number of different membrane processes have found
industrial applications.
We shall discuss about four main types of membrane filtration
microfiltration (MF), ultra filtration (UF), nano filtration (NF) and
reverse osmosis (RO).
The driving force for material transport through the membrane in
those four processes is a pressure difference.
These processes are therefore called pressure-driven membrane
processes.

8. Some other Types of Membrane filtration
Electrodialysis , in which the driving force is an electric field.
Pervaporation ( Huang, 1991 ), a separation technique based on
vaporization through perm-selective membranes used in distillation.

9. So what exactly happens in membrane filtration
In membrane filtration, a portion of fluid known as permeate (filtrate)
passes through the membrane, while other constituents are rejected
by the membrane and retained in the retentate (concentrate) steam.

10. Advantages of using Membrane filtration
• They are usually continuous
• Comparatively low energy utilisation
• No phase change of contaminants
• Small temperature change
• Modular design
• Minimum of moving parts
• Physical separation of contaminants

11. Reverse Osmosis (RO)
Reverse Osmosis (RO) is a membrane process used in liquid/liquid
separation. Water is in principle the only material passing through the
membrane; essentially all dissolved and suspended material is
rejected.

12. Uses of Reverse Osmosis (RO)
 Desalination for potable water from sea water, brackish water, for
effluent re-use
 Chemical process industries
 Metals recovery
 Food processing WWT
 Ultrapure water for semiconductors, pharmaceuticals and medical use
 Textile wastewater re-use
 Boiler feed water
 Dairy industry WWT
 Treatment of hazardous materials

13. Micro filtration (MF)
Micro filtration (MF) is a process where ideally only suspended solids
are rejected, while even proteins pass the membrane freely.
Microfiltration is loosely defined as a membrane separation process
using membranes with a pore size of approximately 0.03 to 10
micronas.

14. Uses of Micro filtration (MF)
Wine, Drinking Water, Dextrose clarification, Hydrocarbon Separation,
Haze removal from gelatin, Milk-fat Separation, Beer clarification,
Food and Beverage, Pharmaceutical/biological, Industrial Wastewater,
Municipal Wastewater Treatment, Paint, Biotechnology

15. Ultrafiltration (UF)
Ultrafiltration (UF) is a process where the HMWC, such as protein, and
suspended solids are rejected, while all LMWC pass through the
membrane freely.
HMWC=High molecular weight component, such as Protein
LMWC=Low molecular weight component, such as NaCl

16. Uses of Ultrafiltration (UF)
Juice clarification, Domestic wastewater, Increase cheese yield,
More industrial wastewaters, Gelatin concentration,
Protein harvesting, Electroplating wastewater, Petroleum processing,
Protein from cheese whey, Wastewater re-use,
Concentration of oil emulsions, Potable water (THM concern),
Pharmaceutical industry,
Abattoir (blood recovery) etc.

17. Nanofiltration (NF)
NF rejects only ions with more than one negative charge, such as
sulfate or phosphate, while passing single charged ions. NF also rejects
uncharged, dissolved materials and positively charged ions according to
the size and shape of the molecule in question.

18. Uses of Nanofiltration (NF)
Molecular separation, Non-thermal solvent recovery,
Room temperature solvent exchanges, Removal of tar,
Fractionation of crude extracts, Purification of gas condensates,
Extract amino acid from blood and cell culture.

20. Flux / Rate of flux
Rate at which the permeate flows through the membrane
• Units: kg /m2d
gal / ft2d
• Factors affecting the flux rate are the applied pressure, the volumetric
flow rate of feed across the membrane surface, its temperature and
its viscosity.

21. Membrane Material Selection
1. High permeate flux
2. Good retention capability according to the specific application
3. Good mechanical strength
4. Chemical stability and inertness
5. Bio-inertness (if used with enzymes and other biologically active materials)
6. Thermal stability
7. Resistance to cleaning and sanitizing agents
8. Resistance against microbial action
9. Smooth, fouling resistant surface
10. Compliance with all other food safety requirements
11. Availability in module types compatible with the specific application
12. Long service life
13. Affordable cost.

22. Membrane Configurations
‘ Membrane configuration ’ refers to the geometry of the membrane
and its position in space in relation to the flow of the feed fluid and of
the permeate.
1. Spiral wound: Flexible permeate spacer between 2 flat membrane
sheets
2. Hollow fibre: inside out / outside in flow
3. Tubular : either single or in a bundle, inside – outside
4. Plates and frame: Series of flat membrane sheets and support
plates

23. Spiral wound configuration

24. Hollow fibre configuration

25. Tubular configuration

26. Plates and frame configuration

27. Thank you