How do the Coldstream FTO+ Filters work?
Understanding filtration by ceramic and activated carbon
The ceramic in the Coldstream FTO+ water filter is primarily used to remove fine particles, sediment, bacteria and parasites. Acting as a physical barrier, it retains solid contaminants and micro-organisms before water passes through to the activated carbon. This helps protect and extend the life of the activated carbon by preventing larger particles from reaching it, ensuring the most efficient and durable filtration possible.
Activated carbon eliminates or greatly reduce smaller contaminants such as chemicals and heavy metals, mainly due to the saturation of its pores. When activated carbon filters water, contaminants such as heavy metals, chemicals, and organic matter adsorb to the porous surface of the carbon.
Activated carbon loses its effectiveness after about six months of use. Over time, the pores of the carbon fill up and can no longer effectively adsorb new contaminants, reducing its filtration capacity.
Adsorption is a process by which molecules, ions or atoms of a fluid (gas or liquid) adhere to the surface of a solid. This phenomenon is due to physical or chemical forces between the molecules of the fluid and those of the solid surface. Here are some key points about adsorption:
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Porous surface
Activated carbon, for example, has an extremely porous surface that offers a vast surface for adsorption. The pores and cracks in activated carbon provide sites where contaminants can become fixed.
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Adsorption forces
The adsorption forces can be of two types: physisorption and chemisorption. Physisorption involves van der Waals forces, which are relatively weak and reversible. Chemisorption, on the other hand, involves stronger and often irreversible chemical bonds.
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Adsorption capacity
The ability of a material to adsorb contaminants depends on the size and structure of its pores, as well as the chemical nature of its surface. The larger the specific surface area of the material, the higher its adsorption capacity.
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Saturation
Over time, the pores of activated carbon fill with adsorbed contaminants. Once the pores are saturated, the material can no longer adsorb new contaminants, reducing its effectiveness.
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Applications
Adsorption is widely used in various applications including water filters, air purifiers, dehumidifiers and industrial gas and liquid purification processes.
How adsorption works in the Coldstream FTO+ water filter
When a water filter containing activated carbon is used contaminants in water, such as volatile organic compounds (VOCs), pesticides, herbicides, heavy metals, and chloroforms, are attracted to and attached to the surface of activated carbon. The pores of the activated carbon capture these contaminants, allowing clean water to pass through. However, once the pores are saturated, the filter needs to be replaced to maintain its effectiveness.
In summary, adsorption is a critical process for many filtration systems, capturing and retaining a wide variety of contaminants to purify fluids.