Mechanical filtration of water is a physical process where untreated water passes through a filter medium to remove suspended solids.
Mechanical filtration is a fundamental method used in water treatment to physically separate larger impurities from water. In mechanical filtration, untreated water passes through a mesh filter or cartridge that traps suspended particles on the surface or within the filter. This process is effective at removing visible or microscopic solid materials suspended in the water flow.
How Mechanical Filtration Works
The core principle is simple: water flows through a barrier with small openings. These openings are smaller than the suspended particles you want to remove. As the water passes through, the solid particles are caught and retained by the filter material, while the cleaned water continues on.
Think of it like a sieve for water. The size of the holes in the "sieve" (the filter media) determines the size of the particles that can be removed.
What Does it Remove?
Mechanical water filters are primarily designed to remove larger suspended material. According to the reference provided, mechanical filters mostly remove:
- Sand
- Silt
- Clay
- Loose scale
- Organic matter
These are the types of particles that contribute to turbidity or cloudiness in water.
Types of Mechanical Filters
Mechanical filters come in various forms, often referred to as:
- Mesh Filters: Similar to screens, these trap particles on the surface.
- Cartridge Filters: Water passes through a cylinder made of pleated material, spun fibers, or other media, trapping particles throughout the filter depth.
- Media Filters: Beds of sand, gravel, or other granular materials can also be used for mechanical filtration, often in larger systems.
Where is it Used?
Mechanical filtration is a crucial first step in many water treatment processes, serving as a pre-filter to protect other treatment stages (like activated carbon filters or reverse osmosis membranes) from getting clogged by large particles. It's used in:
- Household water filters (under-sink, whole-house)
- Industrial water treatment
- Swimming pool filtration
- Aquariums
By removing suspended solids, mechanical filtration improves water clarity and can extend the life of subsequent, more sensitive filtration or purification systems.
