Activated Carbon for Water and Wastewater Treatment: Is it Different?
Activated carbon is used in water filters to absorb and remove impurities such as organic and inorganic compounds, pesticides, and chlorine to purify and reduce odors in the water.
Activated Carbon for Water and Wastewater Treatment
To provide context for the discussion of the different types of activated carbon used in water and wastewater treatment, it is important to first understand the variety of contaminants found in well water, river water, and wastewater.
What are the contaminants in well water?
Contaminants in well water can include dissolved minerals such as iron, manganese, and calcium, as well as bacteria, viruses, and chemicals from fertilizers, pesticides, and other sources.
Other contaminants may include radon, arsenic, and nitrates, depending on the geology and land use in the surrounding area.
What are the contaminants in river water?
Contaminants in river water can include sediment, silt, and debris from erosion and human activities.
Additionally, industrial waste, heavy metals, and other pollutants from nearby factories and wastewater treatment plants can contaminate river water.
River water can also contain dissolved minerals, bacteria, viruses, and chemicals from pesticides and fertilizers used in agriculture.
Also read:
- Anthracite for water filtration
- Why is activated carbon used in water treatment?
What are the contaminants in waste water?
Wastewater can contain a wide range of contaminants, including organic and inorganic compounds, nutrients, heavy metals, pathogens, and other substances that can harm human health and the environment.
Organic compounds can come from sources such as human and animal waste, food processing, and industrial activities.
These compounds can include volatile organic compounds (VOCs), pesticides, herbicides, and pharmaceuticals. Inorganic compounds can come from sources such as heavy metals, which can be toxic to humans and aquatic life.
Nutrients, such as nitrogen and phosphorus, can lead to excessive plant and algae growth in water bodies, leading to harmful algal blooms and degrading water quality.
Pathogens, such as bacteria and viruses, can also be present in wastewater and cause illnesses in humans and animals.
Proper treatment and disposal of wastewater are essential to remove these contaminants and protect public health and the environment.
Treatment processes may include physical, chemical, and biological treatments to remove or reduce contaminants to safe levels.
What is the iodine number of activated carbon?
The iodine number of activated carbon is a measure of its adsorption capacity for iodine and is expressed as the milligrams of iodine that one gram of carbon can adsorb (on a dry basis) when the residual concentration of iodine in the solution is 0.02 N.
It is a common variable used to evaluate the operational capacity of granular or pelleted activated carbons, as it reflects the ability of the carbon to adsorb certain types of contaminants.
The higher the iodine number, the greater the adsorption capacity of the carbon. However, it should be noted that the iodine number is just one of many variables that can be used to evaluate the effectiveness of activated carbon, and other factors such as pore size, surface area, and chemical properties should also be considered.
The iodine number is essentially a measure of the iodine that is absorbed into the pores of activated carbon and can be used as an indicator of the available pore volume. Water treatment activated carbons usually have iodine numbers between 600 and 1100.
Also read:
- What is zeolite?
- Absorption mechanism of zeolite
How do I choose activated carbon for well water, river water, and waste water based on the iodine number?
The iodine number is a key factor in choosing the appropriate activated carbon for water treatment.
For well water treatment, a higher iodine number is recommended as the water often contains organic contaminants, which require a high surface area for effective adsorption.
Activated carbon with an iodine number of 800-1100 is typically recommended for well water treatment.
Well water treatment often involves the use of additional media, including but not limited to silica sand, manganese greensand, and chlorine.
For river water treatment, a lower iodine number may be sufficient as the contaminants are typically less concentrated than in well water. Activated carbon with an iodine number of 600–800 is commonly used for river water treatment.
Other filtration media like silica sand, zeolite, and chemical coagulants such as aluminum sulfate and PAC are commonly employed in sedimentation processes for river water treatment.
For wastewater treatment, the contaminants are often in higher concentrations and require a higher adsorption capacity. Activated carbon with an iodine number of 900–1100 is often used for wastewater treatment.
To treat wastewater, a combination of activated carbon and waste-decomposing bacteria is a commonly used method.
It is important to note that the iodine number is not the only factor to consider when choosing activated carbon for water treatment.
Other factors such as particle size, pH, and specific contaminants present in the water should also be taken into account.
A thorough understanding of the water source and contaminants is necessary to choose the most effective activated carbon for water treatment.
Also read:
- What is silica sand?
- Zeolite for aquarium
Can I make activated carbon iodine 1100 at home?
It is not recommended to make activated carbon with an iodine number of 1100 at home as it requires specialized equipment and processes that can be dangerous to attempt without proper training and facilities.
Activated carbon is usually made in large industrial settings using high temperatures and specific raw materials.
Additionally, producing activated carbon with a high iodine number requires precise control of the activation process, which is difficult to achieve without sophisticated equipment.
Therefore, it is best to purchase activated carbon from a reputable supplier that can provide the quality and specifications needed for specific applications.