Question

Define filtration.

Answer 1

Hint: Filtration is the basic type of separation techniques and has equal importance as other methods have. Some of the other separation techniques are handpicking, sublimation, evaporation etc.

Complete Solution :
Let us study the basics of filtration firstly,
Filtration-
It is a physical process in which separation of solid particles takes place from the liquids or gases by using a filter or a membrane; acting as a medium of separation. This medium will retain the solid particles and let the liquid or gas to pass through it.
Our desired product can be either the clarified fluid or the solid particles, eventually forming a cake. The membrane causing the filtration is called a filter and the clarified liquid obtained is called filtrate.

Requirements for the filtration process to take place are basically,
1. A filter medium
2. A fluid with suspended solids
3. A driving force such as pressure differences which would be responsible for the fluid flow
4. The filter (mechanical device) that would be a medium of filtration.

Filtration can be physical, biological or chemical operation to separate solids from the suspended fluids. In chemistry, it is used for the separation of materials of different chemical compositions.
Some day to day examples of the process are-
-Vacuum cleaners
-Kidneys are biological filters in human body
-Tea or coffee filtered daily in our home

Note: As some fluid remains on the feed side, filtration is an imperfect process. In the practical world, centrifugation is an alternative method of filtration; this can be used when the solids cannot be filtered well.
- Otherwise, filtration is a more efficient method than the process of decantation; but consumes more time.