Characterization and use of activated carbons prepared from bagasses for liquid-phase adsorption

The adsorption of two commercial dyes and phenol from water on activated carbons was investigated at 30 C. The carbons were prepared from bagasses and were activated by steam with different extents of burn-off by varying the temperature in the range of 750-840 degreesC. Pore structures of the carbons were characterized by the t-plot method based on N-2 adsorption isotherms. Three simplified models including the pseudo-first-order equation, pseudo-second-order equation, and intraparticle diffusion models were used to test the adsorption kinetics. It was shown that the adsorption of dyes could be best fitted by the intraparticle diffusion model; the kinetic parameter was calculated and correlated with the extent of burn-off of the carbons. Neither of the three models had a preference for describing the adsorption of phenol, presumably due to its combined control of chemisorption and intraparticle diffusion. (C) 2002 Elsevier Science B.V. All rights reserved.