Introduction of activated carbon | ApplicationsLiquid-phase
Water purification
City tap water
The water sources for waterworks in Japan are lakes and rivers. In some cases, the water may not be suitable for drinking with conventional treatment due to algal odors or contaminants.
Powdered or granular activated carbon is used to purify water at waterworks.
When purification is insufficient only with activated carbon, high-performance purification treatment methods involving combination with ozonation, etc., are used.
Furthermore, processing methods involving multiplying microbes in the granular activated carbon layer to remove biodegradable organic matter are also available.
Flowchart of advanced purification process
Drinking water industry
Raw water for drinking and making beer or rice wine should be tasteless and odorless, and is therefore processed using activated carbon.
Household water purifier
Household water purifier
Free chlorine is always included in tap water, in addition to odorants and traces of trihalomethane, in some cases.
Granular activated carbon or fiber-type activated carbon included in a cartridge is used to remove these contaminants.
Coconut shell activated carbon, which has a large surface area, is appropriate for dechlorination.
Ultrapure water
Granular activated carbon is used in preprocessing to protect the ion exchange resin and reduce load during the production of ultrapure water.
Water purification
Sewage treatment
In normal processing for sewage treatment, standard for effluent may not be satisfied in some cases. Therefore, activated carbon is used for advanced treatment.
Industrial waste water
Normally processed industrial effluent may not satisfy the discharge standard. In such cases, activated carbon is used for advanced treatment.
Decolorization and refinement
Sugar industry
Crude original carbohydrate solutions and starch sugar are impure in many cases and are colored. Therefore, to make white sugar, powdered activated carbon and/or granular activated carbon is used in addition to ion exchange resin.
Amino acid industry, pharmaceutical purification
Crude amino acid or pharmaceutical agent solutions are also impure in many cases and are colored. Therefore, powder activated carbon and/or granular activated carbon is used in addition to ion exchange resin.
Brewage
Powdered activated carbon is used to remove colored materials due to aging in alcohol and to reform flavor.
As activated carbon for brewing requires the absence of iron, strict purification is performed.
Recovery of precious metal
The gold content in gold ore is only of the order of several g/Ton.
Gold ore is crushed and gold is extracted with cyanidation soda solution. Gold is adsorbed by contacting activated carbon and this extraction liquid.
The activated carbon that has adsorbed gold is liquated with fresh cyanidation soda solution. Electrolysis is performed on the concentrated effluent to recover the gold.
In this case, coconut shell activated carbon is widely used.
Representative example of gold recovery (CIP method)
KURARAY COAL™ used for liquid phase
KURARAY COAL™ used for liquid phase is as follows:
| Name | Shape | Grain size（mesh） | Application |
|---|---|---|---|
| PW | Powder | 100 mesh or less | Water purification, water treatment |
| PK | Decolorization, purification | ||
| GW | Granular shape | 10×32, 20×42, 32×60, etc. | Water purification, water treatment |
| GW-H | Decolorization, purification, collection of gold | ||
| GLC | 10×32, 16×42, etc. (chemical liquid regeneration available) |
Decolorization, purification, pharmaceutical purification, brewage | |
| T-S | Granular shape | 10×32, 20×42, 32×60, etc. | Purifier (silver-impregnated activated carbon) |