How to choose an activated carbon filter?

An activated carbon filter is a type of water filtration system that uses activated carbon to remove impurities and contaminants from water. Activated carbon is a form of carbon that has been processed to have small, low-volume pores that increase the surface area available for adsorption or chemical reactions.

Adsorption: Activated carbon filters work through a process called adsorption, where contaminants in the water are attracted to the surface of the carbon particles and are trapped within the pores of the carbon.

Removal of Contaminants: Activated carbon filters are effective at removing a variety of contaminants from water, including chlorine, volatile organic compounds (VOCs), sediment, taste and odor compounds, and certain chemicals and pesticides.

Types of Activated Carbon Filters:

• Granular Activated Carbon (UDF/GAC): These filters consist of loose granules of activated carbon and are commonly used in point-of-use systems like pitchers or faucet filters.
• Block Activated Carbon (CTO): These filters are made of compressed carbon block and are often used in under-the-sink or whole-house filtration systems.

Next we will discuss in detail the differences between UDF filter elements and CTO filter elements

UDF carbon filter

The UDF filter is a granular activated carbon filter that works based on the adsorption properties of activated carbon. When water passes through the UDF filter, the granular activated carbon adsorbs pollutants such as chlorine, organic compounds, and odors in the water, improving the water quality. This adsorption process can effectively remove odors and colors in the water and improve the taste of the water.

Features:

• Preliminary filtration: The UDF filter is suitable for preliminary filtration of larger particulate matter and odors in the water, effectively improving the water quality.
• Easy to replace: UDF filters are usually designed as easy-to-replace filter elements, and users can easily replace the filter element as needed to maintain the filtration effect.
• Relatively low cost: UDF filter elements are relatively low in cost compared to other filter types and are an affordable water treatment option.

Applicable scenarios:

• Home tap water filtration
• Tap filtration
• Kettle or kettle filter element

CTO carbon filter

The CTO filter element is a compressed activated carbon filter element. Its working principle is similar to that of the UDF filter element. It uses the adsorption of activated carbon to remove pollutants in the water. Compressed activated carbon usually has a higher adsorption capacity and can effectively remove smaller particles of pollutants, such as chlorine, heavy metals, organic compounds, etc.

Features:

• Deep filtration: CTO filter elements are suitable for deep filtration of tiny particles and more pollutants in water, providing more comprehensive water quality improvement.
• Efficient adsorption: Due to the characteristics of compressed activated carbon, CTO filter elements usually have a higher adsorption capacity and can effectively remove more types of pollutants.
• Wide range of applications: CTO filter elements are suitable for various water treatment systems, including household and commercial systems, and can meet the filtration needs of different scenarios.

Applicable scenarios:

• Home overall water treatment system
• Commercial water treatment equipment
• Areas with more special water quality problems

Comparison between UDF and CTO carbon filter

Activated carbon filters work through a process called adsorption, where contaminants in a fluid (such as a gas or liquid) adhere to the surface of the activated carbon. Here's how activated carbon filters work:

1. Porous Structure: Activated carbon is a form of carbon that has been processed to have a very large surface area per unit volume, typically by creating a network of pores and crevices. This porous structure provides a vast surface area for contaminants to adhere to.
2. Adsorption: When fluid passes through the activated carbon filter, contaminants in the fluid come into contact with the carbon surface. The contaminants are attracted to the surface of the carbon due to various forces (such as Van der Waals forces) and are trapped in the pores or on the surface of the carbon.
3. Chemical Bonds: Some contaminants are also removed through chemical bonding with the activated carbon. Certain molecules can chemically bond to the carbon surface, further enhancing the filtration process.
4. Removal of Contaminants: As the fluid passes through the activated carbon filter, contaminants such as chemicals, gases, odors, and some metals are effectively removed from the fluid. This process results in cleaner and purified fluid emerging from the filter.
5. Regeneration: Over time, the pores of the activated carbon may become saturated with contaminants, reducing its efficiency. Activated carbon filters can often be regenerated by heating the carbon to high temperatures to burn off the adsorbed contaminants, rejuvenating the surface for further use.

Activated carbon filters are commonly used in various applications such as water purification, air purification, gas masks, and in industrial settings to remove impurities and pollutants from fluids. Their effectiveness in adsorbing a wide range of contaminants makes them a popular choice for filtration systems.

Water Filtration

• Chlorine: Activated carbon filters can effectively remove chlorine and its byproducts from water, improving taste and odor.
• Volatile Organic Compounds (VOCs): These can include chemicals like benzene, toluene, and xylene, which are often found in household cleaning products or paints.
• Pesticides and Herbicides: Activated carbon filters can help reduce the presence of these agricultural chemicals in water.
• Trihalomethanes (THMs): Byproducts of water disinfection processes that can be harmful in high concentrations.
• Heavy Metals: Certain heavy metals like lead, mercury, and cadmium can be adsorbed by activated carbon filters.
• Industrial Chemicals: Filters can also help remove industrial chemicals and pollutants from water sources.

Air Filtration

• Odors and Fumes: Activated carbon filters are effective at removing odors from cooking, pets, smoke, and other sources.
• Volatile Organic Compounds (VOCs): Similar to water filtration, carbon filters can trap VOCs from indoor air sources.
• Formaldehyde: Found in many household products, formaldehyde can be effectively removed by activated carbon filters.
• Allergens: While not the primary function of carbon filters, they can also help reduce certain allergens like dust mites and pollen.
• Smoke Particles: Carbon filters can help trap smoke particles and odors from cigarettes or wildfires.

Other Applications

• Gas Masks: Activated carbon is used in gas masks to adsorb harmful gases and chemicals from the air.
• Air Purifiers: Activated carbon filters in air purifiers can help improve indoor air quality by removing a variety of pollutants.
• Refrigerator Filters: Some refrigerator water filters use activated carbon to remove contaminants and improve the taste of water and ice.

Overall, activated carbon filters are versatile and widely used for their ability to effectively remove a broad spectrum of contaminants and pollutants from air and water sources.

In the above content, we have explained the difference between UDF and CTO filter cartridges in detail. In short, CTO filter elements have smaller particle sizes and uniform pore structure, so they have higher filtration efficiency and can remove a wider range of impurities. However, they have lower water flow rates and are generally more expensive than UDF filter elements.

UDF filter elements have significantly higher water flow rates and higher cost performance, but they are less effective in removing certain impurities.

In daily use, we often use the two filter elements together, with PP melt-blown filter elements, to form a three-stage filtration system for household water filters. Of course, you can also evaluate and choose according to the specific water quality conditions.