What is a carbon filter?
A carbon filter is a type of filter that uses activated carbon to remove impurities from water, air, or gas. Activated carbon is a form of carbon that has been processed to have many tiny pores, which increase its surface area and ability to trap contaminants. Activated carbon filters work by adsorption, which means that the pollutants stick to the surface of the carbon granules and are removed from the fluid.
Carbon filters are commonly used for water purification, air filtering, and industrial gas processing. They can remove chlorine, sediment, volatile organic compounds (VOCs), smoke, odor, and other pollutants from water and air. However, they are not effective at removing minerals, salts, and dissolved inorganic substances.
They can improve the quality of water by reducing harmful substances and enhancing taste and odor. Carbon filters are also environmentally friendly, as they are made from natural materials and can be recycled or regenerated.
Types of Carbon filter and what they remove from water?
There are two main types of carbon filters for water filtration: granular activated carbon (GAC) and carbon block. They both use activated carbon to remove contaminants from water, but they have different advantages and disadvantages. Let’s explain them to you in detail:
Granular activated carbon (GAC)
GAC filters are made of chunks or granules of activated carbon that are packed in a container. Water flows through the container and comes into contact with the porous surfaces of the GAC granules. The contaminants in the water are then trapped by the small pore sizes of the granules, or by their electrostatic or chemical attraction to the carbon surface.
GAC filters are usually cheaper and easier to install than carbon block filters. They can also handle higher flow rates and pressures without clogging. However, they have some drawbacks as well. GAC filters have less surface area than carbon block filters, which means they can remove fewer contaminants and have a shorter lifespan. They can also allow some contaminants to pass through if the water flow is too fast or uneven, which is called channeling. Additionally, GAC filters can promote bacterial growth if they are not properly maintained or replaced.
GAC filters are effective at removing chlorine, sediment, volatile organic compounds (VOCs), taste and odor from water. However, they are not very good at removing minerals, salts, dissolved inorganic substances, heavy metals, pesticides, herbicides, or microorganisms.
Carbon block filters
Carbon block filters are made of powdered activated carbon that is compressed into a solid block. Water flows through the block and comes into contact with the fine pores of the carbon particles. The contaminants in the water are then trapped by the same mechanisms as GAC filters, but with more efficiency and precision.
Carbon block filters have several advantages over GAC filters. They have more surface area and smaller pore sizes, which means they can remove more contaminants and last longer. They also prevent channeling and bacterial growth, as they have a uniform structure and a bacteriostatic agent. Moreover, carbon block filters can be impregnated with different materials that enhance their filtration performance, such as silver, copper, zinc, or KDF. These materials can help remove additional contaminants such as heavy metals, cysts, bacteria, viruses, or chlorine byproducts.
Carbon block filters are effective at removing the same contaminants as GAC filters, plus some more. They can remove minerals, salts, dissolved inorganic substances, heavy metals, pesticides, herbicides, microorganisms, and chlorine byproducts from water. However, they are more expensive and require more pressure than GAC filters. They can also clog faster if the water has a lot of sediment or turbidity.
Working of carbon filter in water purifier
The working of a carbon filter in a water purifier is based on the principle of adsorption. Adsorption is the process of trapping molecules or particles on the surface of a solid material. In this case, the solid material is activated carbon, which is a form of carbon that has been processed to have many tiny pores and a large surface area. Activated carbon can attract and hold various impurities from water, such as chlorine, sediment, volatile organic compounds (VOCs), taste, odor, and more.
Step 1: The water enters the water purifier and goes through a sediment filter, which removes large particles such as dirt, sand, rust, and debris from the water. This protects the carbon filter and other components from getting clogged or damaged.
Step 2: The water passes through the carbon filter, which is made of activated carbon granules or blocks. Activated carbon is a form of carbon that has many tiny pores and a large surface area, which makes it able to trap various impurities from water by adsorption. Adsorption is the process of sticking molecules or particles to the surface of a solid material.
Step 3: The activated carbon in the carbon filter adsorbs contaminants such as chlorine, sediment, volatile organic compounds (VOCs), taste, odor, and more from the water. The contaminants are held on the surface of the carbon granules or blocks and are removed from the water. The purified water then flows out of the carbon filter and goes to the next stage of filtration.
Step 4: The carbon filter needs to be replaced periodically, as it can get saturated with contaminants and lose its adsorption capacity. The frequency of replacement depends on the quality of the water and the usage of the purifier. Some water purifiers have indicators that show when the carbon filter needs to be changed.
How do you know when a carbon filter needs replacement?
Carbon filters in water purifiers are designed to remove contaminants and impurities from water, such as chlorine, organic compounds, and some heavy metals. Over time, these filters can become saturated with the contaminants they’ve trapped, and their effectiveness decreases. Here’s how you can determine when a carbon filter needs replacement:
- Flow Rate Slows: Water flow becomes slower than usual, indicating a clogged filter.
- Change Indicator: Filter change indicator (light, display, color change) reaches the set point.
- Odor/Taste Change: Unusual taste or odor in purified water suggests an exhausted filter.
- Maintenance Schedule: Include filter replacement in your regular maintenance routine.
- Water Quality Test: Compare water quality before and after filtration with testing kits.
- Recommended Time: Follow manufacturer’s recommendation for filter replacement time.
- Pro Tip – Replace the filter timely to maintain effective contaminant removal and overall water quality.