Filtration is a process used to separate solid particles from a liquid by passing it through a porous medium, resulting in a clear liquid called filtrate. The document discusses various types of filtration, mechanisms involved, and its applications in different fields, including water treatment and pharmaceutical manufacturing. It also outlines the importance of filtration in obtaining sterile products and the equipment used in the process.

1. Filtration
S. I MAKRANI
Assistant Professor
Department of Pharmaceutics
Ali Allana College of Pharmacy Akkalkuwa

2. Content
 Definition
 Process of filtration
 Mechanisms of filtration
 Application of filtration
 Type of filtration
 Equipment's used in filtration

3. • Filtration may be defined as a process of separation of solids from a fluid by passing the
same through a porous medium that retains the solids but allows the fluid to pass
through. OR
• It is a process used to separate solid particles from a liquid with the help of a filter or
pores of filter paper. . OR
• In simple words, filteration is the action or process of filtering something.
• Examples The most common example is making tea.
• While preparing tea, a filter or a sieve is used to separate tea leaves from the water.
• Through the sieve pores, only water will pass.
• The liquid which has obtained after filtration is called the filtrate; in this case, water is
the filtrate.
• The filter can be a paper, cloth, cotton-wool, asbestos, or glass-wool, sand, or any
other porous material.
Filtration
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4. Fig. Principle of filtration 2

5. • The mixtures are of two main types:
• Homogeneous mixtures and Heterogeneous mixtures.
• A homogeneous mixture is a mixture that is uniform throughout.
• A heterogeneous mixture is a mixture that is not uniform throughout, i.e.,
ingredients of the mixture are distributed unequally.
• Air is a homogeneous mixture of different gases, including oxygen, nitrogen,
carbon dioxide, and water vapour.
• Homogeneous mixtures are sometimes also called solutions; especially when
it is a mixture of a solid dissolved in a liquid.
• An example of a heterogeneous mixture is the mixture of sand in water.
• On shaking, sand will stay undissolved and are distributed unevenly.
Process of filtration
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6. Slurry:
• The suspension to be filtered is known as slurry.
Filter medium:
• The porous medium used to retain the solids is known as filter medium.
Filter cake:
• The accumulated solids on the filter are referred to as filter cake,
Filtrate:
• The clear liquid passing through the filter is filtrate.
Clarification:
• When solids are present in a very low concentration, i.e., not exceeding
1.0% w/v, the process of its separation from liquid is called clarification
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7. • Straining
• Sedimentation
• Impaction
• Interception
• Adhesion
• Flocculation
• Chemical and Physical adsorption
• Biological growth
Figure : Steps involved in mechanism of filtration
Mechanism of filtration
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8. • Some of the mechanisms are:
• Straining: Similar to sieving. i.e. the particles of larger size cannot pass
through the smaller pore size of the filter medium.
• Impingement: the solids are retained on the filter medium.
• Entanglement : Particles become entangled in the mass of fibres due to
smaller size of particles than the pore size. Thus the solids are retaincd on
the filter medium.
• Attractive forces: Solids are retained on the filter medium as a result of
attractive forces between particles and filter medium.
• Sedimentation: The particles within the filter settle on the filtering
medium.
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9. • Based on the mechanism,
 Surface filtration:
 Depth filtration:
 Membrane Filtration:
• Surface filtration: Surface filtration involves the removal of material
suspended in a liquid by means of sieving.
• Depth filtration: In this method, the removal of suspended material from the
liquid suspension is performed by passing the liquid through a filter bed
composed of granular or compressible Filter medium.
• Membrane Filtration: Membrane filtration is a separation process that uses
a semi Permeable membrane.
Types of filtration
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10.  During manufacturing of sterile products, it is necessary to remove
smallest particle. Therefore, air is filtered through HEPA filters (high
efficiency particulate air filters) to get sterile air.
 The solution, suspension, eye drops, elixirs etc. should be free from
suspended solids. Filtration is major step during production of such
formulations.
 Filtration methods are used in home to clarify potable water
 Filtration is necessary to separate substances of different chemical
composition
 On industrial scale filtration is used for dewaxing of oils.
 Filtration technique is used to treat sewage and waste water
treatment.
Application of filtration
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11. Plate and frame filter press
Figure . Construction of Plate and frame filter press 9

12. Filter leaf
Figure . Construction of Filter leaf 10

13. Drum filter
Figure . Construction of Drum filter 11

14. Meta filter
Figure . Construction of Meta filter 12

15. Cartridge filter
Figure . Construction of Cartridge filter 13

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