Difference Between Filtration and Purification

The key difference between filtration and purification is that filtration is a technique that separates solids from fluids via filtering off the fluid through a barrier whereas purification is a process of separating unwanted components from a fluid via different techniques such as filtration and disinfection.

Filtration is a purification technique in which we use a barrier through which a fluid can be filtered off. This removes the solid components in the fluid. Purification is a very broad term in which we can discuss various methods other than filtration that is useful in purifying a sample.

CONTENTS

1. Overview and Key Difference
2. What is Filtration
3. What is Purification
4. Side by Side Comparison – Filtration vs Purification in Tabular Form
5. Summary

What is Filtration?

Filtration is the technique of removing solids in a fluid via passing the fluid through a barrier that can hold the solid particles. This technique can be a physical, mechanical or biological operation. A fluid can be a liquid or a gas. The fluid that we get after the filtration is “filtrate”. The barrier that we use for the filtration is “filter”. It can be a surface filter or a depth filter, either way, it traps solid particles.

Usually, filtration is an imperfect technique of purification. This is because some solid particles may go through the filter while some fluid may remain on the filter without going to the filtrate. There are different types of filtration such as hot filtration, cold filtration, vacuum filtration, ultrafiltration, etc. Moreover, the applications of this technique include the followings;

• To separate particles and fluid in a suspension
• Coffee filter: to separate coffee from the ground
• Belt filters to separate precious metal during mining
• To separate crystals from the solution during the recrystallization process in organic chemistry
• Furnaces use filtration to prevent the furnace elements from fouling with particulates

What is Purification?

Purification is the technique of removing any unwanted particles from a sample in order to isolate the desired compound. We use different methods as purification techniques for the removal of foreign substances and contaminants. Finally, we get an “isolate” from purifying a sample.

In organic chemistry, the most common purification techniques are crystallization, sublimation, distillation, chromatography, etc. In general chemistry, we use different techniques such as affinity purification, filtration, centrifugation, evaporation, smelting, refining, distillation, adsorption, etc. as separation techniques.

What is the Difference Between Filtration and Purification?

Filtration is the technique of removing solids in a fluid via passing the fluid through a barrier which can hold the solid particles whereas purification is the technique of removing any unwanted particles from a sample in order to isolate the desired compound. Therefore, filtration is a form of purification technique that we can use to separate a solid from a fluid (a gas or a liquid). The filtration gives a “filtrate” at the end of the process whereas purification gives an “isolate”. Therefore, this is the key difference between filtration and purification.

The below infographic presents the difference between filtration and purification in tabular form for quick reference.

Summary – Filtration vs Purification

A filtration is a form of purification technique that we use to separate different components in a sample. The key difference between filtration and purification is that the filtration is a technique that separates solids from fluids via filtering off the fluid through a barrier whereas the purification is a process of separating unwanted components from a fluid via different techniques such as filtration and disinfection.

Reference:

1. Helmenstine, Anne Marie, Ph.D. “Filtration Definition and Processes (Chemistry).” ThoughtCo, Jun. 22, 2018. Available here 
2. “List of Purification Methods in Chemistry.” Wikipedia, Wikimedia Foundation, 6 Aug. 2018. Available here

Image Courtesy:

1.”FilterFunnelApparatus”By Smokefoot – Own work, (Public Domain) via Commons Wikimedia
2.”Affinity Chromatography Technique”By Tinojasontran (Public Domain) via Commons Wikimedia