Adsorption of dyes and phenols from water on the activated carbons prepared from corncob wastes

Pore structures and physical properties of the activated carbons prepared from corncob wastes at various activation temperatures (830, 860, 890°C.) were first studied. Equilibria and rates of adsorption of two commercial dyes, phenol, and 3-chlorophenol from water on such activated carbons were then measured at 30 °C. All adsorption isotherms of the solutes could be well fitted by the Langmuir equation. Three simplified kinetic models including pseudo-first-order equation, pseudo-second-order equation, and intraparticle diffusion model were selected to follow the adsorption processes. It was shown that the adsorption of both phenols could be best described by the pseudo second-order equation, but that of both dyes best by the intraparticle diffusion model. Kinetic parameters of each best-fit model were calculated and discussed.