Regardless of whether you’re using water for cooking or drinking purposes, water filtration is a crucial requirement in every household. Depending on where your water is sourced from it may contain harmful contaminants like dirt, suspended particles, pesticides, and other impurities.
Without water filtration systems, the contaminants cannot be removed from the water which ultimately affects your health by causing certain diseases. This is why it is important to use water filters.
There are different water filtration systems including activated carbon filters. But what is activated carbon and how do activated carbon filters work? More importantly, how good are they in terms of removing contaminants? Here is a detailed insight into this.
For starters, activated carbon is a type of carbon typically used to remove harmful contaminants from water. It can also be used to remove contaminants from the air amongst many other applications.
Here is a more detailed insight into activated carbon and activated carbon filters.
What Is Activated Carbon?
Activated carbon is also referred to as activated charcoal which is basically a carbon element used for the filtration of different particles both from water and air. The reason why it is called activated is because it is processed in a way that leads towards small sized pores.
These pores are also low volume so that the overall surface area for adsorption and/or chemical reactions is increased. Since it is highly microporous, a single gram of activated carbon has over 3000 m2 of surface area. This high surface area leads towards better adsorption.
Adsorption here refers to the ability of a surface to catch particles. When a liquid passes through a surface capable of adsorption the suspended particles get stuck to the surface using adsorption. This is the basic principle behind using activated carbon in water filters.
Furthermore, activated carbon is made from natural materials like coconut husks. Other sources of activated carbons include the waste product of paper pills. These products are first converted into charcoal or carbon and then the properties of adsorption are added to it.
What Is Activated Carbon Filter?
Activated carbon filters are made from solid carbon which is typically in the form of a powdered block. It can also be in granular forms. Activated carbon filters are used in water purification systems for the purpose of purifying water and increasing the efficiency of water systems.
These filters are designed to remove suspended particles including organic matter from water and chemicals like chlorine. Furthermore, these filters can also help remove the color changing chemicals and odors from water -hence removing turbidity from water as well.
Chlorine is usually added to water for purification purposes specifically if the city provides you with water. However, certain amounts of chlorine can be present in water in the post-treatment water which can cause chlorine decontamination.
To remove this decontamination, activated carbon filters can come in handy. However, when it comes to removing microbes or lowering down the hardness of water, activated carbon filters will be of no use.
Talking of how activated carbon filters are made, first the coconut shells are burned in the absence of oxygen. Nitrogen or other inert gases are used during the burning process. Once it is processed, the resultant carbon is steamed, or chemical procedures are applied to activate the carbon.
This requires the carbon to be heated under 750 – 950 degrees Celsius in steam. The activated carbon filters that are made using this procedure leads to fine pores. This allows the activated carbon filters to retain suspended particles more efficiently as compared to standard filters.
To further add, there are different types of activated carbon. Here is an insight into this:
Types of Activated Carbon:
- GAC – Granulated Activated Carbon: GAC comprises of large particles of activated carbon. They have a rather small surface area in contrast to other forms of activated carbon.
- PAC – Powdered Activated Carbon: PAC are made from grounded or a crushed form of carbon. These are in a powdered form and similar to other types, the powdered form is also activated.
- EAC – Extruded Activated Carbon: EAC is made by mixing with PAC. This fusion is made with the help of a binding agent which produces a sphere or cylinder shaped block of carbon.
- BAC – Bead Activated Carbon: BAC is another type of activated carbon which is made from a petroleum pitch.
- Impregnated Carbon: Impregnated carbon is also a type of activated carbon which contains a mix of inorganic compounds. These include silver, iodine amongst others and are thinly spread across the internal layer of the carbon.
- Woven Carbon: Woven carbon gets its name due to its structure. It is woven into the fibers of carbon thus resulting in a woven structure or a cloth like texture.
- Polymer Activated Carbon: Polymer activated caron is another type of activated carbon which contains a biocompatible polymer. This is an advanced form of activated carbon, and the addition of a biocompatible polymer protects the small pores of the carbon block to stay open. It is distinguished by a smooth and permeable outer surface.
How Does Activated Carbon Work?
Activated carbon filters work in a very simply process of adsorption. Adsorption is a chemical process which happens when certain organic elements are exposed to the activated carbon and initiates a chemical reaction.
The result of this chemical reaction is to allow the organic particles to bind to the surface of the activated carbon filter. Since the filter is of high porosity, it is able to retain a greater number of impurities.
This results in a much cleaner and purified water as the contaminants like organic particles, suspended particles, and harsh chemicals have been removed from the water.
Furthermore, if you install an activated carbon filter in water purification systems that support multiple it will also protect the system as well. What happens is that activated carbon filters serve as a protection layer for other filter membranes and protect them from dust.
What Is Activated Carbon Used For?
Activated carbon based filters are used for two different purposes. These include:
- Air purification – Activated carbon filters can be installed in air purifiers. These help remove odor causing particles and other pollutants from the air in your surroundings. This results in a cleaner and fresher air thus greatly improving the air quality.
- Water purification – Activated carbon filters play a huge role in water filtration systems. It can be installed in different type of filter systems including countertop water filters, pitcher filters, and under sink filters to help purify the water and make it safer for drinking purposes.
- Industrial uses – Activated carbon filters can also be used on industrial level. These filters can be used for the treatment of sewage water, for metal finishing, for different pharmaceutical operations, and purifying beverages that are distilled.
- Agricultural uses – Activated carbon is also used in different agricultural applications as well. It can be used as an additive in animal feed. It is also used as a natural pesticide to help agricultural yields. Furthermore, it also helps in disinfection.
- Environmental uses – Activated carbon has certain environmental uses such as treatment of ground water and helping in the cleaning of spills.
- Cosmetic uses – Activated carbon plays a role in cosmetic applications as well. It is used to remove harmful toxins and other contaminations from cosmetic products. Activated carbon is also used as an ingredient in different products like facial masks, toothpastes, and shampoos.
- Mercury Removal – Activated carbon can be used for removing mercury gas from the air as well. It is infused with sulfur and halogen to help remove mercury gas.
- Life support system – Interestingly activated carbon is also used in the spacesuits. It is added to the life support systems which helps contaminants from the air supply and results in a pure supply of oxygen to the astronauts.
Are Activated Carbon Filters Safe?
This is often doubted by many people as they have certain concerns about the safety of using carbon in the treatment processes of water. Despite the fact that activated carbon filters are made from naturally existing materials, people still are skeptical.
However, activated carbon filters are extremely safe. The only concern with carbon filters is that they may produce carbon fines. These are suspended solids either black or dark grey in color. These appear right after the filter is installed in a filtration media.
However, these are normal and tend to appear when you’re using granular carbon filters. Although they may appear bad but there is nothing wrong with these solids. These are not harmful and can be flushed away by simply cleaning the filters.
If there were any issues with the safety of activated carbon it wouldn’t have been used so widely specifically in the medical, agricultural, environmental, and air purification purposes.
Is Activated Carbon The Same As Activated Charcoal?
Activated carbon and activated charcoal are often used interchangeably. Both these terms refer to the remainder products of an incomplete process of combustion. Ideally, when wood is burnt the readily burnable material is burnt, which leaves a black solid comprising of carbon.
Similarly on an industrial level, when a substance is heated in a vacuum environment, it will result in charcoal. This process releases volatile compounds, and the leftovers mainly comprise of trace particles of carbon. Thus, both activated carbon and activated charcoal can be used interchangeably.
Ideally both activated carbon and charcoal have the properties of adsorption since both materials are highly absorbent. These will effectively capture organic particulates and chemicals including VOCs.
Both carbon and charcoal are called activated due to the process that both these elements undergo thus making them efficient at capturing gases. Both these elements when exposed to hot air, steam, or CO2, a mesh of small pores is produced thus increasing their surface area.
Since both activated carbon and activated charcoal are made with the same procedures and perform the same task, they are essentially the same.
Can Activated Carbon Remove Ammonia?
Yes, activated carbon can remove ammonia from contaminated waters. According to a research study on removing ammonia from liquid hospital waste, activated carbon successfully removed ammonia from the hospital waste.
To test this, a sample of 100 ml of hospital waste was taken and activated carbon was added to the mix. This solution was thoroughly stirred so that the activated carbon elements could mix with the waste. This resulted in lowering the concentration of ammonia from the water.
For further readings, you can see the entire research report here.
Can Activated Carbon Remove Chlorine?
Yes, activated carbon can lower the concentration of chlorine or remove it entirely from your water source. In fact, using activated carbon in water is the best way to get rid of chlorine from your water.
According to the EPA, activated carbon can remove over 32 different types of chlorine byproducts from your tap water including total THMs (Trihalomethanes). THMs are the most commonly existing compounds present in water mainly formed due to the presence of chlorine.
Does Activated Carbon Filter Remove Bacteria?
Yes, activated carbon filters can remove disease causing bacteria from your source water. These filters can remove a number of contaminations including pesticides, viruses, volatile organic compounds, and chemicals like hydrogen sulfide, nitrogen and even metals.
According to the EPA, these filters can remove over 14 different types of pesticides from your water. Similarly, over 12 types of herbicides are also removed from your water.
Using activated carbon filters to remove contaminations from your water leaves you with a pure form of water that can readily be consumed either for drinking purposes or cooking purposes.