Used activated carbon – what to do about it?

The use of activated carbon in environmental protection and other separation processes has expanded considerably in recent years in the technologically advanced countries of the world. World production of this interesting adsorbent material is currently approaching 1 million tons per year and is growing constantly. The largest use of activated carbon is in the field of drinking and wastewater treatment, waste gas treatment, chemical methods of gold mining and refining processes in industrial, pharmaceutical and food processing. The sorbent used needs to be regenerated in order to be able to continue to serve or to dispose of it ecologically if its regeneration or reactivation is not possible. The article deals with the possibilities of the restoration of sorption properties of used by regeneration and reactivation procedures, describes the differences between these processes, and also deals with evaluation of the sorption capacities of carbonaceous sorbents with restored sorption capacity. The technologies that use integrated regeneration of the saturated adsorbent directly in the adsorption plant and technologies that replace the saturated adsorbent with new ones, which show more favorable investment costs, are currently used in the operational practice. The saturated adsorbent used with organic substances is usually not disposed of, but regenerated or reactivated in the regeneration / reactivation plant. Both of these technologies have also been introduced and operated in the Czech Republic in the past. In the Czech Republic, there are currently two industrial facilities in operation designed to regenerate activated carbon saturated with organic substances. In the case of regenerated / reactivated sorbents, it is important to have a suitable sorbent certificate with a restored structure, which determines the degree of restoration of the porous structure of the sorbent. Because of this, it is necessary to adjust the expected adsorption capacity of the sorbent with a restored porous structure for the captured substances, and subsequently also the sorbent exchange interval. Only in this way will the adsorption equipment meet the emission limits determined throughout the operation.