Types of Carbon Filtration
- Activated carbon has many purposes in the water treatment industry. The main use is to improve the taste and odor by neutralizing the Chlorine based disinfectants and adsorbing certain organic compounds.
Type of Activated Carbon
- Bituminous – a coal-based used for general de-chlorination, taste/odor improvement and organic removal.
- Coconut Shell* – carbon made from coconut shells. Has a higher surface area than bituminous. Higher capacity for de-chlorination than bituminous.
*Watts Premier only uses Coconut Shell based Carbon Block filters.Activated carbon cartridges typically come in two forms:
- Granular Activated Carbon (GAC) Cartridges
- Carbon Block Cartridges
Activated Carbon Structure
- Activated Carbon is an extremely porous material, which causes it to have a high surface area (up to 1100 square meters per gram). This gives it a high capacity for contaminant removal in water treatment.
- Many contaminants are attracted to this high surface area like we are attracted to the earth by gravity. This process is called adsorption.
- Chlorine/Chloramine is chemically neutralized by a reaction when the activated carbon is introduced.
Contaminants Removed by Activated Carbon
- Chlorine - Reacts with the carbon and is neutralized
- Chloramine - Reacts with carbon and is neutralized
- Organics - Adsorbed by the carbon with 1 micron filtration
- VOCs - Adsorbed by the carbon with 1 micron filtration
- Lead - Adsorbed by an additive in the carbon with 1 micron filtration
- Cysts - Mechanically filtered by the block with 1 micron filtration
Granular Activated Carbon
- Effective Taste, Odor, and Chlorine reduction
- Designed for maximum adsorption
- Post filter to reduce carbon fines
- Available in a variety of sizes and flow rates
- Temperatures to 100°F
- Tolerant of high Sediment waters.
- Good general purpose drinking water cartridge.
- Typically designed for low flow rates.
- May have a media migration problem.
Carbon Block Filters
- Economically priced
- High Sediment efficiency with maximized chemical reduction capacities
- Greater Chlorine removal capacity than alternative technologies
- Nominal 1 – 5 micron rating
- Temperatures to 165°F
- Very high capacity.
- Some blocks capable of Cyst / VOC reduction
- Little or no media migration.
- Can be designed for higher flow rates
- May need a sediment pre-filter