Desorption of 4-chlorophenol from spent granular activated carbon in continuous flow ultrasonic reactor

Abstract

The purpose of this work was to explore the application of low frequency ultrasound for the desorption of 4-chlorophenol (4-CP) from saturated granular activated carbon (GAC) in a continuous flow ultrasonic reactor. The effects of operating parameters such as the amount of adsorbent, intensity of ultrasound irradiation, temperature, flow rate of desorbing solution, NaOH, ethyl alcohol, and mixture of NaOH and ethyl alcohol on the desorption process were investigated. The obtained results show that the desorption decreased with increasing the amount of adsorbent and intensity of ultrasound irradiation. The amount of 4-CP desorption gradually increased with the increase in temperature and flow rate of desorbing solution. Using NaOH or/and ethyl alcohol as desorbing solutions causes an enhancement of the desorption. Desorption was improved with increasing the concentration of NaOH and ethyl alcohol in the desorbing solution. Future studies should innovate the ultrasound-assisted desorption process in a pilot-scale test that applies this desorption procedure to a GAC adsorber used in organic compounds removal.