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Filtration - Definition, Examples, Method, FAQs

Filtration - Definition, Examples, Method, FAQs

Edited By Team Careers360 | Updated on Jul 02, 2025 04:34 PM IST

What is filtration process?

Filtration Definition(Filter Definition) and Filtration Meaning: A filter is a membrane that passes suspended solids through its pores in order to separate them from a liquid. In other words, filtering Separates suspended solids from liquids.

Solid particles are removed from a liquid or gaseous fluid via filtration by using a filter media that permits the liquid to pass through while retaining the solid particles. There may be a product desired in either the clarified fluid or the solid particles removed from the fluid. The solid filter cake, as well as the fluid filtrate, are sometimes recovered during chemical mechanism of filtration. Filters can also be used for other media, such as electricity, light, and sound.

This Story also Contains
  1. What is filtration process?
  2. Filtration Process
  3. A process that occurs physically
  4. Methods of filtering
  5. Filtration Examples:

Filtration processFiltration

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Filtration Process

People who lived in the early stages of human evolution were skilled in filtering muddy water filtration process by scooping a hole in the sand on the river bank deep enough to reach the water. Water would trickle into the hole from the hole after being filtered by the sand. It is common in cities to purify water using a similar process, on a larger scale with refinements.

Filters consist of (1) a filter medium, (2) a fluid, (3) a driving force driving the fluid, and (4) an apparatus (the filter) that holds the filter medium, contains the fluid and permits force to be applied. To produce a comprehensive range of filter equipment, it is possible to combine different methods for treating and removing the cake, for removing the clear filtrate, as well as for driving the liquid differently.

The most common types of mixtures are homogeneous mixtures and heterogeneous mixtures. The homogeneity of a mixture can be assessed by looking at the physical properties of the mixture. The ingredients of a heterogeneous mixture are not distributed equally across the mixture, i.e., the ingredients are not uniformly distributed over the mixture. Gases such as oxygen, nitrogen, carbon dioxide, and water vapor make up air, which is composed of different gases.

A homogeneous mixture is sometimes also called a solution; in particular, a mixture of a solid and a liquid. A heterogeneous mixture is a mix of sand and water. During shaking, the sands remain undissolved and spread unevenly. In a heterogeneous mixture, you will find sand particles floating in the mixture, eventually sinking to the bottom. Separating mixtures from contaminants and purifying them is done with different kinds of filters. Filters of different pore sizes, even at home, can be used depending on the type of contaminant - large or small.

A process that occurs physically

A fluid can be a liquid, a gas, or a supercritical fluid, and filters are used to separate the particles and liquid in a suspension. An isolated component can be either one or both of the components, depending on the application. Separating materials of different chemical compositions is accomplished through filtration as a physical operation.

An appropriately diluted solution is chosen which dissolves one of the components without destroying the other. A component of the mixture will pass through the filter after dissolving in the chosen solvent, while the remaining component remains. Processes such as filtration are widely used in chemical engineering. A biofilter is a combined filter and biologically digested device, such as the biofilter. [citation needed]

The process of filtration is different from that of sieving, where separation is achieved at a single layer of perforations (a sieve). When particles are sieved, those that are too large to pass through the holes are retained (see particle size distribution). The multilayer lattice of the filtration method retains particles that are unable to pass through its tortuous channels. As well as blocking the filter lattice, large particles can encumber the filter surface, preventing fluid from crossing the surface (blinding).

Filters are generally referred to as sieves or filters in the commercial context because they consist of thin lattices that become the main separation zone, even though these products did not meet filtration standards. The separation takes place via filtration instead of adsorption, which uses charge. The majority of commercially available adsorption devices contain activated charcoal and ion-exchange resin and, despite their name, do not perform the primary mechanical function of filtration.

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Methods of filtering

It is possible to filter water in different ways. The choice of how to dissolve (partially) or suspend the solid depends largely on the nature of the solid. There are three types of general filtration. Gravity filtration is the simplest. Typically, liquid mixtures are poured from above onto a filter medium (e.g., filtration process using filter paper) and gravity pulls the liquid down. Filters leave solids on the surface while liquid passes through them.

In vacuum filtration, a Büchner flask and hose are used to create a vacuum, which draws the fluid through the filter (generally with the help of gravity). The solid can be dried using this method and separation is greatly accelerated. There is another technique to form pressure differences between both sides of the filter using a pump. Because gravity does not cause pressure differences at the sides of the filter, pump filters do not need to be vertical.

Filtration using cold water: Cold filtration is used to cool a solution quickly, causing small crystals to form. Initial dissolution of a solid using this method is required. An ice bath, before filtration, is a common method for placing containers containing solutions. When using hot filtration, the solution, filter, and funnel are heated to minimize crystals forming during filtration. The smaller surface area of stemless funnels makes them useful in preventing crystal growth. A crystal clogs up the funnel or prevents crystallization of the second component when this method is used.

NCERT Chemistry Notes:

Filtration Examples:

Making tea is one of the most common examples. Separating tea leaves from water is accomplished with a filter or sieve during tea preparation. There are no other materials passing through the sieve pores. The filtrate is the liquid that has been obtained after filtering; in this case, water is the filtrate Various materials are used for filters, including paper, cloth, cotton-wool, asbestos, slag- or glass-wool, unglazed earthenware, sand, etc. There is a need for filtration when it comes to water and sewage treatment. In order to fully understand matter and its states, we need to look at the three states of matter.

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Frequently Asked Questions (FAQs)

1. 1. What are the application of filtration process?

As part of water treatment, filtration is also important. Water treatment and water purification can become an expensive process if filters are not used appropriately. The quality of water treatment filters is not regulated by any government health commission or department. The effectiveness of filters can therefore vary widely between manufacturers

2. 2. Filtration - what is it?

The most common types of mixtures are homogeneous mixtures and heterogeneous mixtures. The homogeneity of a mixture can be assessed by looking at the physical properties of the mixture. Heterogeneous mixtures are those that are not uniform throughout, that is, the components are distributed unevenly.

3. 3. What is the definition of Filtration?

A filter is a membrane that passes suspended solids through its pores in order to separate them from a liquid. In other words, filtering Separates suspended solids from liquids.

4. 4. Write the some examples of filtering.

Making tea is one of the most common examples. Separating tea leaves from water is accomplished with a filter or sieve during tea preparation.  It is the only water that passes through the sieve pores. After filtration, the liquid that is obtained is called the filtrate; here it is water.

5. 5. What are the physical processes involved in filtration?

A fluid can be a liquid, a gas, or a supercritical fluid, and filters are used to separate the particles and liquid in a suspension. An isolated component can be either one or both of the components, depending on the application.

6. How does filtration differ from sedimentation?
Filtration actively separates solids from liquids using a physical barrier, while sedimentation relies on gravity to settle heavier particles out of a mixture over time. Filtration is generally faster and more complete.
7. How does filtration differ from other separation methods?
Filtration separates solid particles from liquids or gases based on particle size, while other methods like distillation separate components based on boiling points, and chromatography separates based on affinity for a stationary phase.
8. How does particle size affect filtration?
Particle size determines whether a substance will be retained by the filter or pass through. Particles larger than the filter's pore size will be trapped, while smaller particles will pass through with the filtrate.
9. How does temperature affect filtration?
Temperature can affect filtration by changing the viscosity of the liquid being filtered. Higher temperatures generally decrease viscosity, allowing for faster filtration, but may also affect the solubility of some compounds.
10. How does the shape of filter paper affect filtration?
The shape of filter paper can affect filtration speed and efficiency. Fluted filter paper increases surface area and speeds up filtration, while flat filter paper may be more suitable for retaining very fine particles.
11. Can filtration separate dissolved substances from a solution?
No, simple filtration cannot separate dissolved substances from a solution. It only separates undissolved solid particles from liquids or gases. Other methods like distillation or crystallization are needed for dissolved substances.
12. What is the filtrate in a filtration process?
The filtrate is the liquid or gas that passes through the filter medium during filtration. It contains particles smaller than the filter's pore size and is collected in a separate container.
13. What is the residue in filtration?
The residue, also called the retentate, is the solid material that remains on the filter after filtration. It consists of particles too large to pass through the filter pores.
14. What is cross-flow filtration?
Cross-flow filtration is a technique where the feed flows parallel to the filter membrane, reducing the buildup of particles on the filter surface. This method is often used in industrial processes to maintain filtration efficiency over time.
15. What is membrane filtration?
Membrane filtration uses a thin, semi-permeable material as the filter medium. It can separate particles and molecules based on size, charge, or other properties, and is often used in water treatment and biotechnology applications.
16. How does the concept of filter cake relate to filtration efficiency?
The filter cake is the layer of particles that builds up on the filter surface during filtration. While it can enhance particle retention, an excessively thick cake can significantly slow down filtration and may require removal.
17. What is the role of filter paper in filtration?
Filter paper acts as the porous medium through which the mixture passes. It traps solid particles while allowing liquids or gases to flow through, effectively separating the components based on particle size.
18. What is ultrafiltration?
Ultrafiltration is a membrane filtration process that uses pressure to separate very small particles, macromolecules, and colloids from liquids. It can remove particles in the 0.001 to 0.1 micron range.
19. How does filtration rate change over time during a filtration process?
Filtration rate typically decreases over time as particles accumulate on or in the filter, increasing resistance to flow. This is known as filter fouling and may require cleaning or replacement of the filter.
20. What is the role of pressure drop in filtration?
Pressure drop is the difference in pressure before and after the filter. It increases as the filter becomes clogged, indicating reduced efficiency. Monitoring pressure drop helps determine when to clean or replace filters.
21. What are the main components of a filtration setup?
The main components of a filtration setup include a filter medium (e.g., filter paper), a funnel to hold the filter, a flask or beaker to collect the filtrate, and sometimes a vacuum source for faster filtration.
22. What is the difference between gravity filtration and vacuum filtration?
Gravity filtration relies on gravity to pull the liquid through the filter, while vacuum filtration uses suction to speed up the process. Vacuum filtration is faster but requires additional equipment.
23. How does pore size affect filtration efficiency?
Pore size determines which particles can pass through the filter. Smaller pore sizes can trap finer particles but may slow down filtration, while larger pore sizes allow for faster filtration but may not capture smaller particles.
24. What is the difference between qualitative and quantitative filtration?
Qualitative filtration aims to separate components without concern for precise measurements, while quantitative filtration involves careful measurement and collection of both the filtrate and residue for analysis or further use.
25. How does pressure affect the rate of filtration?
Increased pressure (as in vacuum filtration) accelerates the filtration process by forcing the liquid or gas through the filter more quickly. However, excessive pressure may damage the filter or force unwanted particles through.
26. What is filtration in chemistry?
Filtration is a separation technique used to separate solid particles from a liquid or gas mixture. It involves passing the mixture through a porous material (filter) that allows the liquid or gas to pass through while retaining the solid particles.
27. How does filtration play a role in water purification?
Filtration is a crucial step in water purification, removing suspended solids, bacteria, and other contaminants. Various filtration methods, from simple mechanical filters to advanced membrane systems, are used in water treatment.
28. How does filtration factor into the isolation of elements?
Filtration is often used in the isolation of elements to separate solid precipitates from liquid solutions. This can be a crucial step in purifying elements after chemical reactions or in extracting elements from ores.
29. What is meant by the term "filter integrity"?
Filter integrity refers to the ability of a filter to perform its intended function without leaks or defects. It's crucial in applications where complete removal of particles is necessary, such as in pharmaceutical manufacturing.
30. What is meant by the term "filter efficiency"?
Filter efficiency refers to the percentage of particles of a specific size that a filter can remove from a fluid stream. Higher efficiency filters remove a greater percentage of particles but may also create more flow resistance.
31. What is the purpose of using filter aids in filtration?
Filter aids are materials added to improve filtration efficiency. They create a more porous filter cake, increase flow rate, and help capture finer particles that might otherwise pass through the filter.
32. How does cake filtration differ from depth filtration?
In cake filtration, particles accumulate on the surface of the filter, forming a cake that becomes part of the filtering medium. In depth filtration, particles are trapped within the porous structure of the filter medium itself.
33. What is the difference between microfiltration and nanofiltration?
Microfiltration removes particles in the 0.1 to 10 micron range, while nanofiltration can remove much smaller particles, typically in the 0.001 to 0.01 micron range. Nanofiltration can even remove some dissolved substances.
34. What is backwashing in filtration?
Backwashing is a cleaning process where the flow through a filter is reversed to dislodge trapped particles and restore filtration efficiency. It's commonly used in water treatment and industrial filtration systems.
35. What is diatomaceous earth filtration?
Diatomaceous earth filtration uses the fossilized remains of tiny aquatic organisms as a filter medium. It's highly effective at removing fine particles and is often used in swimming pool filters and food processing.
36. How does centrifugal filtration work?
Centrifugal filtration combines centrifugal force with filtration. The mixture is spun at high speed, forcing it through a filter medium. This method is particularly useful for separating fine particles or when dealing with viscous liquids.
37. What is the difference between dead-end filtration and tangential flow filtration?
In dead-end filtration, the entire feed flows perpendicular to the filter surface, while in tangential flow filtration, the feed flows parallel to the membrane surface. Tangential flow reduces fouling and is often used in biotechnology applications.
38. How does the concept of filter rating relate to filtration efficiency?
Filter rating indicates the size of particles a filter can reliably remove. For example, a 5-micron filter should remove 95-98% of particles 5 microns and larger. Understanding filter ratings is crucial for selecting the right filter for a specific application.
39. What is the difference between surface filtration and depth filtration?
Surface filtration captures particles on the filter's surface, while depth filtration traps particles within the filter medium's structure. Surface filters are typically used for larger particles, while depth filters can capture finer particles.
40. How does filtration contribute to analytical chemistry techniques?
In analytical chemistry, filtration is often used to prepare samples by removing interfering particles before analysis. It's also used in gravimetric analysis to collect and weigh precipitates formed during chemical reactions.
41. How does the concept of filter loading affect filtration processes?
Filter loading refers to the accumulation of particles on or within a filter over time. As loading increases, filtration efficiency may initially improve, but flow rate decreases. Eventually, the filter may become clogged and require cleaning or replacement.
42. What is the role of adsorption in some filtration processes?
In some filtration processes, especially those using activated carbon or other adsorbent materials, adsorption plays a significant role. These filters not only physically trap particles but also chemically attract and hold certain molecules on their surface.
43. How does the concept of flux relate to membrane filtration?
Flux in membrane filtration refers to the rate of permeate flow per unit area of membrane. It's an important parameter in designing and operating membrane filtration systems, as it affects process efficiency and economics.
44. What is meant by the term "filter medium compatibility"?
Filter medium compatibility refers to the chemical and physical suitability of a filter material for a specific application. The filter medium must be able to withstand the conditions of the filtration process without degrading or releasing contaminants.
45. How does filtration contribute to environmental protection?
Filtration plays a crucial role in environmental protection by removing pollutants from air and water. It's used in wastewater treatment, air pollution control systems, and in cleaning up oil spills and other environmental contaminants.

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