Adsorption characteristics of carbon tetrachloride from aqueous solution onto polyacrylonitrile-based activated carbon fiber

Abstract

The isotherm, mechanism and kinetics of carbon tetrachloride (CT) adsorption by polyacrylonitrile-based activated carbon fiber (PAN-ACF) were investigated in batch reactors and a continuous flow reactor, and the regeneration of PAN-ACF was also studied. Freundlich and Dubinin-Radushkevich (D-R) adsorption equations can well describe the adsorption isotherm. CT is mainly adsorbed on the exterior surface of PAN-ACF with low boundary layer effect and rate-controlling step of intra-particle diffusion. The adsorption dynamics in the batch reactor well fits with the pseudo-first-order model, and the breakthrough curves in the continuous flow reactor can be well described by the Yoon-Nelson model. The ACF can be recycled through thermal regeneration, whereas the adsorption capacity decreases from 7.87 to 4.98 mg/g after the fourth regeneration. 78%−94% of CT can be removed from the wastewater of a fluorine chemical plant on a pilot scale, which confirms the efficacy of ACF under industrial conditions. The results indicate that PAN-ACF is applicable to CT removal from wastewater.

A comparison of three methods to regenerate activated carbon saturated by diesel fuels

“…The regeneration of carbon has been extensively studied in wastewater treatment . Commonly used approaches include thermal regeneration, solvent extraction, ultrasound, bioregeneration, oxidation, electrochemical regeneration and microwave irradiation . However, very limited studies have been documented on the restoration of the adsorption capacity of carbons that are spent in the denitrogenation and desulphurisation processes.…”