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 °C. Pore structures of the carbons were characterized by the t-plot method based on N2 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.