What Does a Carbon Filter Take Out of Water？

Carbon water filters are an efficient and cost-effective way to purify water, ensuring a cleaner, safer water supply. Do you know what these filters remove from your water and how they work? This article will delve into these questions and help you choose and use these filters correctly.

What Is A Carbon Filter?

Activated carbon filters use activated carbon as the filter medium. Activated carbon is a carbon material that is activated by hot steam at high temperatures (800-1000°C) under oxygen-free conditions to open its pores and form porous black beads or black porous sponges. This activation process greatly increases the surface area of the carbon, thus enhancing its ability to adsorb impurities. Raw materials for activated carbon usually include bituminous coal, peat and coconut shells, with coconut shells being the most common raw material.

Due to the physical and chemical adsorption properties of activated carbon, chemicals adhere to the surface of the carbon, making carbon water filters effective in adsorbing a wide range of impurities and volatile organic compounds (VOCs) from water. Their effectiveness depends on water flow rate and temperature, so most carbon filters need to be used under low pressure and cold water conditions.

Depending on the degree of dispersion and the purpose of the activated carbon, carbon filters are classified as powdered activated carbon (PAC), granular activated carbon (GAC) and fiber activated carbon (ACF) filters.

• GAC Activated Carbon Filter: It consists of particles of 0.5-5 mm in size, with large specific surface area and efficient adsorption capacity. It can effectively remove pollutants in water, is easy to maintain, and is very suitable for large flow and long-term use, such as industrial water pretreatment, municipal water supply and swimming pool water treatment.
• PAC Activated Carbon Filter: It consists of very fine activated carbon powder, which is usually removed by sedimentation or filtration. Due to the more complicated operation, it is suitable for short-term treatment and emergency treatment.
• ACF Activated Carbon Filter: Made of activated carbon fibers, it has higher adsorption speed and capacity. It is suitable for treating complex pollutants but is more costly and usually needs to be used in combination with other cartridges to achieve the best filtration effect. Commonly used for high efficiency air purification and specific water treatment scenarios.

In addition, according to the different raw materials of activated carbon, carbon filters can also be divided into catalytic carbon filters and coconut shell carbon filters. Catalytic carbon filters have higher chemical reactivity and are suitable for removing specific chemical pollutants. Coconut shell carbon filters are commonly used for drinking water treatment and air purification due to their high density and hardness.

What Does A Carbon Filter Take Out Of Water?

When raw water enters the activated carbon filter, the granular activated carbon, with its large surface area and high adsorption capacity, effectively removes a variety of harmful substances from the water. Here are the main categories of contaminants they can remove:

1) Organic compounds

• Volatile organic compounds (VOCs)： Such as methane, benzene, toluene, and dichloroethane. These compounds are commonly found in industrial pollution and in some household cleaning products.
• Chlorine and Chlorine By-Products： For example, trihalomethanes (THMs) and chloroform, which are by-products of the reaction between chlorine and organic substances during the water disinfection process, are harmful to health when ingested over a long period of time.
• Pesticides and herbicides： These chemicals, such as atrazine and carbendazim, are commonly found in agricultural runoff and contaminate surface and groundwater sources.

2) Odor and odor substances

• Chlorine smell： Activated carbon absorbs any residual chlorine in the water, reducing the disinfectant smell of the water.
• Hydrogen sulfide smell： Such as hydrogen sulfide (rotten egg smell), and activated carbon can effectively remove these odors.
• Chemical smell： Such as the smell of paint and detergent, these odor substances are removed through the adsorption of activated carbon.

3) Hazardous chemicals

• Heavy metals： Metals such as lead, mercury, and copper can come from aging pipes or industrial pollution.
• Microbial contamination: Some bacteria and viruses can be removed by carbon filters, but not all microorganisms can be removed.
• Harmful gasses: Such as ozone, sulfides, and nitrogen oxides are removed through the adsorption capacity of activated carbon.

Although carbon filters are very effective in removing a variety of pollutants, they still have certain limitations. Here are some types of substances that it cannot remove from water:

• Total dissolved solids (TDS): Includes minerals (such as magnesium, potassium, sodium and calcium), salts or metals (such as iron), which are not considered contaminants.
• Arsenic and asbestos: Can only be partially reduced, not completely removed.
• Certain toxic organic compounds: For example, some large organic molecules and a large number of metals.
• Fluoride: Carbon filters have limited effect on the removal of fluoride.
• Radionuclides: Such as uranium, radium, etc.
• Most microbial contaminants: Including bacteria, viruses, cysts, E. coli, protozoa and other microorganisms, carbon filters can only remove some microorganisms and cannot be fully relied on for microbial removal.

What Does A Carbon Filter Do?

Carbon filters (activated carbon filters) are often used in conjunction with other equipment such as sand filter tanks, softeners and membrane treatment systems in the water treatment process to achieve the best water treatment effect. The following are several common combinations and their working principles or process flows:

1. Carbon filter+sand filter

The sand filter uses the physical filtering properties of the sand layer to remove suspended solids, silt and rust from the water through the synergistic effect of multiple layers of filter media. When water flows through the filter bed, larger particles are trapped on the surface of the filter bed or in the pores of the filter media, and smaller particles are removed step by step. The filtered water flows out through the outlet.

The combination of carbon filters and sand filters can efficiently treat water quality. The raw water first enters the sand filter tank for pretreatment, and the sand filter removes larger suspended particles and impurities through physical filtration. After that, the pretreated water flows into the carbon filter to further remove organic matter, residual chlorine, odor and some microorganisms.

This combination is suitable for primary and secondary water treatment and is widely used in scenarios such as household drinking water, industrial water, and swimming pool water treatment.

2. Carbon filter+sand filter+water softener

In the combined use of sand filters, carbon filters, and water softeners, the raw water first passes through the sand filter to remove larger suspended particles and impurities. Next, the filtered water enters the carbon filter to remove organic matter, residual chlorine, and odor, protecting the subsequent water softener.

Finally, the treated water passes through the water softener, using ion exchange resin to remove calcium and magnesium ions and reduce the water’s hardness. This combination can effectively remove a variety of pollutants in the water while reducing the hardness of the water. It is suitable for a variety of application scenarios such as household drinking water and boiler feed water.

3. Pretreatment system + reverse osmosis equipment (or other membrane filtration system)

In water treatment systems, sand filters, carbon filters and water softeners are usually used together as pretreatment processes for reverse osmosis systems. Sand filters remove large particles such as sand, dirt and rust from water through physical filtration.

Carbon filters remove organic matter and residual chlorine from water to prevent them from damaging the reverse osmosis membrane. Water softeners use ion exchange resins to remove calcium and magnesium ions from water, thereby reducing the hardness of water, preventing scale from forming on the reverse osmosis membrane, and further extending the service life of the membrane.

After these three pretreatments, the water will enter the reverse osmosis system, using the high-precision filtration capacity of the semipermeable membrane to remove dissolved salts, organic matter, bacteria and viruses in the water to produce high-purity water. This integrated system is widely used in scenarios with extremely high water quality requirements, such as laboratory water preparation, medical water, and industrial ultrapure water preparation.

The carbon filter itself does not have a high removal rate for most pollutants. The use of other water treatment equipment can achieve more efficient and comprehensive water treatment effects. You can choose a suitable combination of equipment to achieve the best treatment effect according to the specific water quality conditions and needs.

Applications of Carbon Water Filters

Carbon filters are widely used in household drinking water, industrial water, municipal water supply, aquariums and swimming pools, etc. It is mainly used to adsorb organic matter, remove residual chlorine and odor, and protect subsequent treatment equipment. It is a key piece of equipment for improving water quality.

1）Household drinking water treatment

Odor removal: Carbon filters can effectively remove odors and organic matter from well water and improve the taste of drinking water. Used in respiratory masks, exhaust fans, and air conditioners, they can remove unpleasant odors such as animal and smoke.

Removal of residual chlorine: Tap water often contains chlorine for disinfection. Carbon filters can effectively remove residual chlorine and reduce potential harm to the human body.

Removal of organic pollutants: Carbon filters can remove organic compounds in water, such as pesticides, herbicides and volatile organic compounds (VOCs).

2) Industrial water treatment

Pretreatment process: Before reverse osmosis, ultrafiltration, and other membrane treatment processes, carbon filters are often used for pretreatment to remove organic matter and residual chlorine in water and protect membrane elements.

Industrial water purification: In the food, beverage, pharmaceutical, and other industries, carbon filters are used to purify production water to ensure product quality.

3) Municipal water supply

Drinking water treatment: In municipal water supply systems, carbon filters are used to remove organic matter, residual chlorine, and odor in water to improve the quality of tap water.

Wastewater treatment: During wastewater treatment, carbon filters are used to remove organic pollutants and residual chlorides from wastewater to reduce pollution to the environment.

4) Aquarium and aquaculture water

Water purification: Carbon filters are used for water purification in aquariums and aquaculture to remove harmful substances in the water and protect the health of fish and other aquatic organisms.

5) Swimming pool water treatment

Removal of odor and residual chlorine: Carbon filters are used for swimming pool water purification to remove odor and residual chlorine in the water, improve water quality, and provide a better swimming experience.

How To Choose The Right Industrial Carbon Filter?

When choosing the right industrial carbon filter, you need to consider multiple factors to ensure that the equipment meets your specific needs and application scenarios. Here are some suggestions to help you make an informed decision when selecting or customizing an activated carbon filter:

Application: First, identify the type of water source, the main pollutants, and the usage scenario and target water quality. This will help you decide whether to combine other water treatment technologies.

Water volume: Estimate daily water volume requirements and operating hours to determine the appropriate flow rate. If the flow rate is insufficient, it may result in poor filtration results; too high a flow rate will increase unnecessary costs.

Sizing: The volume of water required for the filter will affect its size. Calculate the required volume using the relevant formula and calculate the diameter and height of the filter based on the volume.

With a flow rate of 2.5 m³/h, for example, and assuming a flow rate of 15 m³/m²/h and a contact time of 20 minutes, the required volume is calculated to be approximately 0.055 cubic meters.

Assuming a filter with a height-to-width ratio of 2:1, the diameter is approximately 0.33 meters and the height is approximately 0.66 meters. Choose the appropriate size in combination with the actual space and ease of installation.

Housing material: Carbon filters are available in a variety of housing materials, including stainless steel, fiberglass, plastic and carbon steel. Choose the appropriate material according to the actual needs and budget.

Type: Choose the appropriate form of carbon filter. For example, granular activated carbon (GAC) filters are suitable for long-term, large water volume needs with high durability. Common carbon materials include coconut shell charcoal, coal charcoal, and charcoal charcoal. Selecting high-quality coconut shell charcoal can improve treatment results.

Valve Configuration: Manual or automatic valves are available. Manual valves are lower cost and suitable for simple operation; automatic valves offer greater ease of operation, including automatic backwashing and draining functions.

Automation: Consider automation features such as automatic backwashing, flow monitoring, and timing control, which will reduce labor costs and improve the stability of the system operation. PLC control systems can provide more accurate operation management.

Brand: It is important to choose a reliable equipment brand and supplier. It is recommended to consult a professional water treatment company and refer to user reviews and professional advice to ensure the actual effectiveness and reliability of the equipment. Choose the best quality carbon filter according to your budget.

What Can NEWater Do For You?

NEWater provides customized carbon filter services to meet your specific needs, including different sizes, capacities, materials, colors, and flow rates. Our products are NSF-certified to ensure safety and efficiency. In addition, we also provide high-quality water treatment products such as reverse osmosis filters, ion exchangers, and water desalination equipment.

We also provide comprehensive after-sales services, including installation guidance, maintenance advice, and technical support. Tell us your needs, and we will quickly provide you with efficient and reliable water treatment solutions to improve water quality and protect your health.