What is the process of filtration?

The process of filtration involves passing a heterogeneous mixture through a porous medium, known as a filter, which allows the fluid phase (liquid or gas) to pass through while retaining the solid particles. The driving force for this movement can be gravity, pressure, vacuum, or centrifugal force. As the mixture encounters the filter, particles larger than the pore size of the medium are trapped on the surface or within the depth of the filter, forming a layer called the cake or residue. The fluid that passes through is collected as the filtrate. Over time, the accumulation of particles can clog the filter, reducing flow rate and efficiency, which necessitates cleaning or replacement of the filter medium. The effectiveness of the process depends on factors such as pore size, particle size distribution, viscosity of the fluid, and the pressure applied. This physical separation mechanism is fundamental to achieving purity and clarity in various applications.