Activated carbon is produced from carbon materials such as wood, coal, petroleum residues and so on. Coal is prepared by burning of material in an airless space. This coal is then oxidized at higher temperatures to find a highly porous structure. The activation phase creates irregular channels and pores in solid mass, leading to a very high ratio of surface area to mass (500 to 1500). The activated carbon power is based to these channels and pores.
Use of activated carbon
Activated carbon is used to remove taste, odor, color, organic materials, Haloform, phenolic materials and chlorine.
Activated carbon system:
Company's activated carbon systems are made of steel tanks, PP or iron with epoxy coating.
They consist of a bed of granular activated carbon (GAC). Water is passed through the bed and sufficient time is provided to complete adsorption. This system can be equipped with backwashing, regeneration with steam or acid.
It is recommended to use backwashing operation (creating reverse streaming in the tank) of activated carbon at least once every six months. This removes external material in the bed.
Regeneration of activated carbon:
Activated carbon is regenerated in two ways by using acid and steam.
A - Use of steam: High saturated steam is used for regeneration. First of all it is backwashed with water for 30 minutes, and then it is regenerated 3-4 times with steam.
B - Use of acid: After 30 minutes of backwashing with water, 10% hydrochloric acid is spilled onto activated carbon. After 30 minutes the acid must be discharged. And then it is washed with water without chlorine to removes remaining acid from carbon.
Regeneration with steam is better than regeneration with acid.
About five to ten percent of the activated carbon is lost during the recovery process .It must be replaced with fresh carbon.
Capacity of recycled carbon is less than fresh carbon.
Characteristics of inlet water to activated carbon system:
The main problem with granular activated carbon is bed blockage created by suspended solids in water.
So these suspended solids should be removed (by sand filters, cyclone) before the entering of water into the carbon bed. Activated carbon filter is designed and produced according to the maximum amount of water passing through the device and its continuous daily use. Therefore water passing through the device must be less than the maximum amount recommended by this company. This preserves activated carbon filter's ability.