Studies on evaluation and utilization of activated carbon. 4. Batch and continuous reactivation of activated carbon with a 100mm.PHI. fluidized bed reactor.

Abstract

High temperature reactivation of activated carbons used for treatments of phenolic wastewater efluents was investigated by using a 100mmφ fluidized bed reactor equipped with a screw feeder. Reactivation could be carried out in both batch and continuous systems. Batch reactivation was carried out by using a reactor installed with one perforate plate (that is, one hearth), and continuous reactivation was performed by using a reactor installed with one additional perforate plate (that is, a co-current two-hearth fluidized bed reactor).Specific surface area and methylene blue adsorption capacity of the spent carbon could be regenerated to 90% of the levels of the virgin carbon by simple heat treatment in nitrogen.Improvement of such properties as specific surface area and methylene blue adsorption capacity through reactivation with steam was slightly less in the continuous system than in the batch system due to the apparent decrease in the reactivation yield caused by the burning of the carbon with the coexisting air and the loss of fine particles produced in the screw feeder. However, sufficiently effective regeneration could be achieved in both systems.The decrease in strength of carbon by reactivation and reactivation losses were larger in the presence of air.The carbon obtained with a yield of about 95-96% in either batch system or in continuous system could be used for the treatment of phenolic wastewater effluents.